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Mod_Rewrite Security

AskApache — Sat, 18 Feb 2012 06:54:18 +0000

Here are some specific htaccess examples taken mostly from my WordPress Password Protection plugin, which does alot more than password protection as you will see from the following mod_rewrite examples. These are a few of the mod_rewrite uses that BlogSecurity declared pushed the boundaries of Mod_Rewrite! Some of these snippets are quite exotic and unlike anything you may have seen before, also only for those who understand them as they can kill a website pretty quick.

Directory Protection

Enable the DirectoryIndex Protection, preventing directory index listings and defaulting. [Disable]

Options -Indexes
DirectoryIndex index.html index.php /index.php

Password Protect wp-login.php

Requires a valid user/pass to access the login page[401]


Order Deny,Allow
Deny from All
Satisfy Any
AuthName "Protected By AskApache"
AuthUserFile /home/askapache.com/.htpasswda1
AuthType Basic
Require valid-user

Password Protect wp-admin

Requires a valid user/pass to access any non-static (css, js, images) file in this directory.[401]

Options -ExecCGI -Indexes +FollowSymLinks -Includes
DirectoryIndex index.php /index.php
Order Deny,Allow
Deny from All
Satisfy Any
AuthName "Protected By AskApache"
AuthUserFile /home/askapache.com/.htpasswda1
AuthType Basic
Require valid-user

Allow from All



SecFilterEngine Off

Allow from All

Protect wp-content

Denies any Direct request for files ending in .php with a 403 Forbidden.. May break plugins/themes [401]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /wp-content/.*$ [NC]
RewriteCond %{REQUEST_FILENAME} !^.+flexible-upload-wp25js.php$
RewriteCond %{REQUEST_FILENAME} ^.+\.(php|html|htm|txt)$
RewriteRule .* - [F,NS,L]

Protect wp-includes

Denies any Direct request for files ending in .php with a 403 Forbidden.. May break plugins/themes [403]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /wp-includes/.*$ [NC]
RewriteCond %{THE_REQUEST} !^[A-Z]{3,9}\ /wp-includes/js/.+/.+\ HTTP/ [NC]
RewriteCond %{REQUEST_FILENAME} ^.+\.php$
RewriteRule .* - [F,NS,L]

Common Exploits

Block common exploit requests with 403 Forbidden. These can help alot, may break some plugins. [403]

RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ ///.*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\?\=?(http|ftp|ssl|https):/.*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\?\?.*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\.(asp|ini|dll).*\ HTTP/ [NC,OR]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*\.(htpasswd|htaccess|aahtpasswd).*\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

Stop Hotlinking

Denies any request for static files (images, css, etc) if referrer is not local site or empty. [403]

RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{HTTP_REFERER} !^http://www.askapache.com.*$ [NC]
RewriteRule \.(ico|pdf|flv|jpg|jpeg|mp3|mpg|mp4|mov|wav|wmv|png|gif|swf|css|js)$ - [F,NS,L]

Safe Request Methods

Denies any request not using GET,PROPFIND,POST,OPTIONS,PUT,HEAD[403]

RewriteCond %{REQUEST_METHOD} !^(GET|HEAD|POST|PROPFIND|OPTIONS|PUT)$ [NC]
RewriteRule .* - [F,NS,L]

Forbid Proxies

Denies any POST Request using a Proxy Server. Can still access site, but not comment. See Perishable Press [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP:VIA}%{HTTP:FORWARDED}%{HTTP:USERAGENT_VIA}%{HTTP:X_FORWARDED_FOR}%{HTTP:PROXY_CONNECTION} !^$ [OR]
RewriteCond %{HTTP:XPROXY_CONNECTION}%{HTTP:HTTP_PC_REMOTE_ADDR}%{HTTP:HTTP_CLIENT_IP} !^$
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

Real wp-comments-post.php

Denies any POST attempt made to a non-existing wp-comments-post.php[403]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*/wp-comments-post\.php.*\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

HTTP PROTOCOL

Denies any badly formed HTTP PROTOCOL in the request, 0.9, 1.0, and 1.1 only[403]

RewriteCond %{THE_REQUEST} !^[A-Z]{3,9}\ .+\ HTTP/(0\.9|1\.0|1\.1) [NC]
RewriteRule .* - [F,NS,L]

SPECIFY CHARACTERS

Denies any request for a url containing characters other than "a-zA-Z0-9.+/-?=&" - REALLY helps but may break your site depending on your links. [403]

RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{THE_REQUEST} !^[A-Z]{3,9}\ [a-zA-Z0-9\.\+_/\-\?\=\&]+\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

BAD Content Length

Denies any POST request that doesnt have a Content-Length Header[403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP:Content-Length} ^$
RewriteCond %{REQUEST_URI} !^/(wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

BAD Content Type

Denies any POST request with a content type other than application/x-www-form-urlencoded|multipart/form-data[403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP:Content-Type} !^(application/x-www-form-urlencoded|multipart/form-data.*(boundary.*)?)$ [NC]
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

Missing HTTP_HOST

Denies requests that dont contain a HTTP HOST Header.[403]

RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteCond %{HTTP_HOST} ^$
RewriteRule .* - [F,NS,L]

Bogus Graphics Exploit

Denies obvious exploit using bogus graphics[403]

RewriteCond %{HTTP:Content-Disposition} \.php [NC]
RewriteCond %{HTTP:Content-Type} image/.+ [NC]
RewriteRule .* - [F,NS,L]

No UserAgent, Not POST

Denies POST requests by blank user-agents. May prevent a small number of visitors from POSTING. [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP_USER_AGENT} ^-?$
RewriteCond %{REQUEST_URI} !^/(wp-login.php|wp-admin/|wp-content/plugins/|wp-includes/).* [NC]
RewriteRule .* - [F,NS,L]

No Referer, No Comment

Denies any comment attempt with a blank HTTP_REFERER field, highly indicative of spam. May prevent some visitors from POSTING. [403]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*/wp-comments-post\.php.*\ HTTP/ [NC]
RewriteCond %{HTTP_REFERER} ^-?$
RewriteRule .* - [F,NS,L]

Trackback Spam

Denies obvious trackback spam. See Holy Shmoly! [403]

RewriteCond %{REQUEST_METHOD} =POST
RewriteCond %{HTTP_USER_AGENT} ^.*(opera|mozilla|firefox|msie|safari).*$ [NC]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.+/trackback/?\ HTTP/ [NC]
RewriteRule .* - [F,NS,L]

Map all URIs except those corresponding to existing files to a handler

RewriteEngine On
RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} !-d
RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} !-f
RewriteRule . /script.php

Map any request to a handler

In the case where all URIs should be sent to the same place (including potentially requests for static content) the method to use depends on the type of the handler. For php scripts, use: For other handlers such as php scripts, use:

RewriteEngine On
RewriteCond %{REQUEST_URI} !=/script.php
RewriteRule .* /script.php

And for CGI scripts:

ScriptAliasMatch .* /var/www/script.cgi

Map URIs corresponding to existing files to a handler instead

RewriteEngine On
RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} -d [OR]
RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} -f
RewriteCond %{REQUEST_URI} !=/script.php
RewriteRule .* /script.php

If the existing files you wish to have handled by your script have a common set of file extensions distinct from that of the hander, you can bypass mod_rewrite and use instead mod_actions. Let's say you want all .html and .tpl files to be dealt with by your script:

Action foo-action /script.php
AddHandler foo-action html tpl

Deny access if var=val contains the string foo.

RewriteCond %{QUERY_STRING} foo
RewriteRule ^/url - [F]

Removing the Query String

RewriteRule ^/url /url?

Adding to the Query String

Keep the existing query string using the Query String Append flag, but add var=val to the end.

RewriteRule ^/url /url?var=val [QSA]

Rewriting For Certain Query Strings

Rewrite URLs like http://askapache.com/url1?var=val to http://askapache.com/url2?var=val but don't rewrite if val isn't present.

RewriteCond %{QUERY_STRING} val
RewriteRule ^/url1 /url2

Modifying the Query String

Change any single instance of val in the query string to other_val when accessing /path. Note that %1 and %2 are back-references to the matched part of the regular expression in the previous RewriteCond.

RewriteCond %{QUERY_STRING} ^(.*)val(.*)$
RewriteRule /path /path?%1other_val%2

Mod_Rewrite Security originally appeared on AskApache.com

Chmod, Umask, Stat, Fileperms, and File Permissions

AskApache — Fri, 17 Feb 2012 11:16:56 +0000

AskApache.com

Unix file permissions are one of the more difficult subjects to grasp.. Well, ok maybe "grasp" isn't the word.. Master is the right word.. Unix file permissions is a hard topic to fully master, mainly I think because there aren't many instances when a computer user encounters them. Windows has been trying to figure it out for decades with little progress, so don't feel bad if you don't know much about it. Unless you're with the program and running Mac or any other BSD/Unix based OS you've never had the ability to secure your system in this most basic and fundamental way. Usually the first time someone encounters file permissions it's because their website was cracked..

.htaccess

$ chmod 604 .htaccess

604 -rw----r--  /home/askapache/cgi-bin/.htaccess

php.cgi

$ chmod 711 php.cgi

$ 711 -rwx--x--x  /home/askapache/cgi-bin/php.cgi

.php.ini

$ chmod 600 php.ini

$ 600 -rw-------  /home/askapache/cgi-bin/php.ini

I'm in the process of developing an updated version of the .htaccess security plugin, and one thing I have been working on is file permissions. Some people had problems trying to create files on their server and I realized it was bad programming on my part.. so I began researching permissions in detail. I went deep into the source code of Apache (which is why this site is called AskApache, BTW), PHP, Python, Ocaml, Perl, Ruby, and POSIX operating systems and got a pretty good handle on it now..

Tips before we dig in

Here's a few things I've learned that I didn't know before (using php).

Deleting Files and Directories

Deleting a file may require chmodding the file to 666 or even 777 before you are able to delete it. You also might have to chmod the parent directory of the file as well. Also, you may have to chdir to the directory the file is in. And lastly you may have to change the owner or group of the file. Further than that you can try renaming the file first then deleting it..

Deleting a directory means you need to remove every file in it first. It needs to be empty. And if your file system uses NFS or some other networked FS you might have even more problems deleting files. If the file you are trying to delete is being used by say, Apache or php then you might have to kill that process first.

Creating Files in Restrictive Environments

My research has been geared to try and make my code as robust as possible, I'm throwing everything but the kitchen sink into some of these functions because so many people are on such different types of servers. To create a file in a restrictive environment is a fun excercise to take.. You can write a file using many different functions, but there are some tricks if they all fail. One trick is instead of trying to "write" the data to the file, you can UPLOAD the data to the server and let PHP handle the file as if you used an upload form. I like to use fsockopen to do it, as some installations have been setup to prevent this type of fake upload.

Then there are the various other hacks like using an ftp connection (if you know the user/pass) to send the file from php, using ssh from php, whatever is available on the hosts php installation. In addition to those more involved workarounds you can often get around this problem by doing little hacks discussed at php.net in the comments for various functions. Such as changing the umask, changing directories with chdir first, creating a temporary file using a function like tempfile and then renaming or copying the tempfile to your desired file which sometimes gives you the permissions needed to write to the location.

If the php installation is newer than you can also look into creating your own stream context to pass write the data direct.

Stat Function

I've created a stat function in php that goes farther than the normal stat function... Just give the function a file to stat, and it returns an array of information.

function askapache_stat($filename) {
 clearstatcache();
 $ss=@stat($filename);
 if(!$ss) die("Couldnt stat {$filename}");
 $file_convert=array(0140000=>'ssocket',0120000=>'llink',0100000=>'-file',0060000=>'bblock',0040000=>'ddir',0020000=>'cchar',0010000=>'pfifo');
 $p=$ss['mode'];
 $t=decoct($ss['mode'] & 0170000);
 $str = (array_key_exists(octdec($t),$file_convert)) ? $file_convert[octdec($t)]{0} : 'u';
 $str.=(($p&0x0100)?'r':'-').(($p&0x0080)?'w':'-').(($p&0x0040)?(($p&0x0800)?'s':'x'):(($p&0x0800)?'S':'-'));
 $str.=(($p&0x0020)?'r':'-').(($p&0x0010)?'w':'-').(($p&0x0008)?(($p&0x0400)?'s':'x'):(($p&0x0400)?'S':'-'));
 $str.=(($p&0x0004)?'r':'-').(($p&0x0002)?'w':'-').(($p&0x0001)?(($p&0x0200)?'t':'x'):(($p&0x0200)?'T':'-'));
 
 $s=array(
 'perms'=>array(
  'umask'=>sprintf("%04o",umask()),
  'human'=>$str,
  'octal1'=>sprintf("%o", ($ss['mode'] & 000777)),
  'octal2'=>sprintf("0%o", 0777 & $p),
  'decimal'=>sprintf("%04o", $p),
  'fileperms'=>@fileperms($filename),
  'mode1'=>$p,
  'mode2'=>$ss['mode']),
 
 'filetype'=>array(
  'type'=>substr($file_convert[octdec($t)],1),
  'type_octal'=>sprintf("%07o", octdec($t)),
  'is_file'=>@is_file($filename),
  'is_dir'=>@is_dir($filename),
  'is_link'=>@is_link($filename),
  'is_readable'=> @is_readable($filename),
  'is_writable'=> @is_writable($filename)),
 
 'owner'=>array(
  'fileowner'=>$ss['uid'],
  'filegroup'=>$ss['gid'],
  'owner_name'=>(function_exists('posix_getpwuid')) ? @reset(@posix_getpwuid($ss['uid'])) : '',
  'group_name'=>(function_exists('posix_getgrgid')) ? @reset(@posix_getgrgid($ss['gid'])) : ''),
 
 'file'=>array(
  'filename'=>$filename,
  'realpath'=>(@realpath($filename) != $filename) ? @realpath($filename) : '',
  'dirname'=>@dirname($filename),
  'basename'=>@basename($filename)),
 
 'device'=>array(
  'device'=>$ss['dev'], //Device
  'device_number'=>$ss['rdev'], //Device number, if device.
  'inode'=>$ss['ino'], //File serial number
  'link_count'=>$ss['nlink'], //link count
  'link_to'=>($s['type']=='link') ? @readlink($filename) : ''),
 
 'size'=>array(
  'size'=>$ss['size'], //Size of file, in bytes.
  'blocks'=>$ss['blocks'], //Number 512-byte blocks allocated
  'block_size'=> $ss['blksize']), //Optimal block size for I/O.
 
 'time'=>array(
  'mtime'=>$ss['mtime'], //Time of last modification
  'atime'=>$ss['atime'], //Time of last access.
  'ctime'=>$ss['ctime'], //Time of last status change
  'accessed'=>@date('Y M D H:i:s',$ss['atime']),
  'modified'=>@date('Y M D H:i:s',$ss['mtime']),
  'created'=>@date('Y M D H:i:s',$ss['ctime'])),
 );
 
 clearstatcache();
 return $s;
}

PHP Stat Function Output

Example output, say from print_r(askapache_stat( __FILE__ ) );

Array(
[perms] => Array
  (
  [umask] => 0022
  [human] => -rw-r--r--
  [octal1] => 644
  [octal2] => 0644
  [decimal] => 100644
  [fileperms] => 33188
  [mode1] => 33188
  [mode2] => 33188
  )
 
[filetype] => Array
  (
  [type] => file
  [type_octal] => 0100000
  [is_file] => 1
  [is_dir] =>
  [is_link] =>
  [is_readable] => 1
  [is_writable] => 1
  )
 
[owner] => Array
  (
  [fileowner] => 035483
  [filegroup] => 23472
  [owner_name] => askapache
  [group_name] => grp22558
  )
 
[file] => Array
  (
  [filename] => /home/askapache/askapache-stat/public_html/ok/g.php
  [realpath] =>
  [dirname] => /home/askapache/askapache-stat/public_html/ok
  [basename] => g.php
  )
 
[device] => Array
  (
  [device] => 25
  [device_number] => 0
  [inode] => 92455020
  [link_count] => 1
  [link_to] =>
  )
 
[size] => Array
  (
  [size] => 2652
  [blocks] => 8
  [block_size] => 8192
  )
 
[time] => Array
  (
  [mtime] => 1227685253
  [atime] => 1227685138
  [ctime] => 1227685253
  [accessed] => 2008 Nov Tue 23:38:58
  [modified] => 2008 Nov Tue 23:40:53
  [created] => 2008 Nov Tue 23:40:53
  )
)

Every Permission 0000 to 0777

This shows what each numeric permission does to a REGULAR file. I'll provide the code to do this below so you can do the same thing on your server.

chmod 0: ----------
chmod 1: ---------x
chmod 2: --------w-
chmod 3: --------wx
chmod 4: -------r--
chmod 5: -------r-x
chmod 6: -------rw-
chmod 7: -------rwx
chmod 10: ------x---
chmod 11: ------x--x
chmod 12: ------x-w-
chmod 13: ------x-wx
chmod 14: ------xr--
chmod 15: ------xr-x
chmod 16: ------xrw-
chmod 17: ------xrwx
chmod 20: -----w----
chmod 21: -----w---x
chmod 22: -----w--w-
chmod 23: -----w--wx
chmod 24: -----w-r--
chmod 25: -----w-r-x
chmod 26: -----w-rw-
chmod 27: -----w-rwx
chmod 30: -----wx---
chmod 31: -----wx--x
chmod 32: -----wx-w-
chmod 33: -----wx-wx
chmod 34: -----wxr--
chmod 35: -----wxr-x
chmod 36: -----wxrw-
chmod 37: -----wxrwx
chmod 40: ----r-----
chmod 41: ----r----x
chmod 42: ----r---w-
chmod 43: ----r---wx
chmod 44: ----r--r--
chmod 45: ----r--r-x
chmod 46: ----r--rw-
chmod 47: ----r--rwx
chmod 50: ----r-x---
chmod 51: ----r-x--x
chmod 52: ----r-x-w-
chmod 53: ----r-x-wx
chmod 54: ----r-xr--
chmod 55: ----r-xr-x
chmod 56: ----r-xrw-
chmod 57: ----r-xrwx
chmod 60: ----rw----
chmod 61: ----rw---x
chmod 62: ----rw--w-
chmod 63: ----rw--wx
chmod 64: ----rw-r--
chmod 65: ----rw-r-x
chmod 66: ----rw-rw-
chmod 67: ----rw-rwx
chmod 70: ----rwx---
chmod 71: ----rwx--x
chmod 72: ----rwx-w-
chmod 73: ----rwx-wx
chmod 74: ----rwxr--
chmod 75: ----rwxr-x
chmod 76: ----rwxrw-
chmod 77: ----rwxrwx
chmod 100: ---x------
chmod 101: ---x-----x
chmod 102: ---x----w-
chmod 103: ---x----wx
chmod 104: ---x---r--
chmod 105: ---x---r-x
chmod 106: ---x---rw-
chmod 107: ---x---rwx
chmod 110: ---x--x---
chmod 111: ---x--x--x
chmod 112: ---x--x-w-
chmod 113: ---x--x-wx
chmod 114: ---x--xr--
chmod 115: ---x--xr-x
chmod 116: ---x--xrw-
chmod 117: ---x--xrwx
chmod 120: ---x-w----
chmod 121: ---x-w---x
chmod 122: ---x-w--w-
chmod 123: ---x-w--wx
chmod 124: ---x-w-r--
chmod 125: ---x-w-r-x
chmod 126: ---x-w-rw-
chmod 127: ---x-w-rwx
chmod 130: ---x-wx---
chmod 131: ---x-wx--x
chmod 132: ---x-wx-w-
chmod 133: ---x-wx-wx
chmod 134: ---x-wxr--
chmod 135: ---x-wxr-x
chmod 136: ---x-wxrw-
chmod 137: ---x-wxrwx
chmod 140: ---xr-----
chmod 141: ---xr----x
chmod 142: ---xr---w-
chmod 143: ---xr---wx
chmod 144: ---xr--r--
chmod 145: ---xr--r-x
chmod 146: ---xr--rw-
chmod 147: ---xr--rwx
chmod 150: ---xr-x---
chmod 151: ---xr-x--x
chmod 152: ---xr-x-w-
chmod 153: ---xr-x-wx
chmod 154: ---xr-xr--
chmod 155: ---xr-xr-x
chmod 156: ---xr-xrw-
chmod 157: ---xr-xrwx
chmod 160: ---xrw----
chmod 161: ---xrw---x
chmod 162: ---xrw--w-
chmod 163: ---xrw--wx
chmod 164: ---xrw-r--
chmod 165: ---xrw-r-x
chmod 166: ---xrw-rw-
chmod 167: ---xrw-rwx
chmod 170: ---xrwx---
chmod 171: ---xrwx--x
chmod 172: ---xrwx-w-
chmod 173: ---xrwx-wx
chmod 174: ---xrwxr--
chmod 175: ---xrwxr-x
chmod 176: ---xrwxrw-
chmod 177: ---xrwxrwx
chmod 200: --w-------
chmod 201: --w------x
chmod 202: --w-----w-
chmod 203: --w-----wx
chmod 204: --w----r--
chmod 205: --w----r-x
chmod 206: --w----rw-
chmod 207: --w----rwx
chmod 210: --w---x---
chmod 211: --w---x--x
chmod 212: --w---x-w-
chmod 213: --w---x-wx
chmod 214: --w---xr--
chmod 215: --w---xr-x
chmod 216: --w---xrw-
chmod 217: --w---xrwx
chmod 220: --w--w----
chmod 221: --w--w---x
chmod 222: --w--w--w-
chmod 223: --w--w--wx
chmod 224: --w--w-r--
chmod 225: --w--w-r-x
chmod 226: --w--w-rw-
chmod 227: --w--w-rwx
chmod 230: --w--wx---
chmod 231: --w--wx--x
chmod 232: --w--wx-w-
chmod 233: --w--wx-wx
chmod 234: --w--wxr--
chmod 235: --w--wxr-x
chmod 236: --w--wxrw-
chmod 237: --w--wxrwx
chmod 240: --w-r-----
chmod 241: --w-r----x
chmod 242: --w-r---w-
chmod 243: --w-r---wx
chmod 244: --w-r--r--
chmod 245: --w-r--r-x
chmod 246: --w-r--rw-
chmod 247: --w-r--rwx
chmod 250: --w-r-x---
chmod 251: --w-r-x--x
chmod 252: --w-r-x-w-
chmod 253: --w-r-x-wx
chmod 254: --w-r-xr--
chmod 255: --w-r-xr-x
chmod 256: --w-r-xrw-
chmod 257: --w-r-xrwx
chmod 260: --w-rw----
chmod 261: --w-rw---x
chmod 262: --w-rw--w-
chmod 263: --w-rw--wx
chmod 264: --w-rw-r--
chmod 265: --w-rw-r-x
chmod 266: --w-rw-rw-
chmod 267: --w-rw-rwx
chmod 270: --w-rwx---
chmod 271: --w-rwx--x
chmod 272: --w-rwx-w-
chmod 273: --w-rwx-wx
chmod 274: --w-rwxr--
chmod 275: --w-rwxr-x
chmod 276: --w-rwxrw-
chmod 277: --w-rwxrwx
chmod 300: --wx------
chmod 301: --wx-----x
chmod 302: --wx----w-
chmod 303: --wx----wx
chmod 304: --wx---r--
chmod 305: --wx---r-x
chmod 306: --wx---rw-
chmod 307: --wx---rwx
chmod 310: --wx--x---
chmod 311: --wx--x--x
chmod 312: --wx--x-w-
chmod 313: --wx--x-wx
chmod 314: --wx--xr--
chmod 315: --wx--xr-x
chmod 316: --wx--xrw-
chmod 317: --wx--xrwx
chmod 320: --wx-w----
chmod 321: --wx-w---x
chmod 322: --wx-w--w-
chmod 323: --wx-w--wx
chmod 324: --wx-w-r--
chmod 325: --wx-w-r-x
chmod 326: --wx-w-rw-
chmod 327: --wx-w-rwx
chmod 330: --wx-wx---
chmod 331: --wx-wx--x
chmod 332: --wx-wx-w-
chmod 333: --wx-wx-wx
chmod 334: --wx-wxr--
chmod 335: --wx-wxr-x
chmod 336: --wx-wxrw-
chmod 337: --wx-wxrwx
chmod 340: --wxr-----
chmod 341: --wxr----x
chmod 342: --wxr---w-
chmod 343: --wxr---wx
chmod 344: --wxr--r--
chmod 345: --wxr--r-x
chmod 346: --wxr--rw-
chmod 347: --wxr--rwx
chmod 350: --wxr-x---
chmod 351: --wxr-x--x
chmod 352: --wxr-x-w-
chmod 353: --wxr-x-wx
chmod 354: --wxr-xr--
chmod 355: --wxr-xr-x
chmod 356: --wxr-xrw-
chmod 357: --wxr-xrwx
chmod 360: --wxrw----
chmod 361: --wxrw---x
chmod 362: --wxrw--w-
chmod 363: --wxrw--wx
chmod 364: --wxrw-r--
chmod 365: --wxrw-r-x
chmod 366: --wxrw-rw-
chmod 367: --wxrw-rwx
chmod 370: --wxrwx---
chmod 371: --wxrwx--x
chmod 372: --wxrwx-w-
chmod 373: --wxrwx-wx
chmod 374: --wxrwxr--
chmod 375: --wxrwxr-x
chmod 376: --wxrwxrw-
chmod 377: --wxrwxrwx
chmod 400: -r--------
chmod 401: -r-------x
chmod 402: -r------w-
chmod 403: -r------wx
chmod 404: -r-----r--
chmod 405: -r-----r-x
chmod 406: -r-----rw-
chmod 407: -r-----rwx
chmod 410: -r----x---
chmod 411: -r----x--x
chmod 412: -r----x-w-
chmod 413: -r----x-wx
chmod 414: -r----xr--
chmod 415: -r----xr-x
chmod 416: -r----xrw-
chmod 417: -r----xrwx
chmod 420: -r---w----
chmod 421: -r---w---x
chmod 422: -r---w--w-
chmod 423: -r---w--wx
chmod 424: -r---w-r--
chmod 425: -r---w-r-x
chmod 426: -r---w-rw-
chmod 427: -r---w-rwx
chmod 430: -r---wx---
chmod 431: -r---wx--x
chmod 432: -r---wx-w-
chmod 433: -r---wx-wx
chmod 434: -r---wxr--
chmod 435: -r---wxr-x
chmod 436: -r---wxrw-
chmod 437: -r---wxrwx
chmod 440: -r--r-----
chmod 441: -r--r----x
chmod 442: -r--r---w-
chmod 443: -r--r---wx
chmod 444: -r--r--r--
chmod 445: -r--r--r-x
chmod 446: -r--r--rw-
chmod 447: -r--r--rwx
chmod 450: -r--r-x---
chmod 451: -r--r-x--x
chmod 452: -r--r-x-w-
chmod 453: -r--r-x-wx
chmod 454: -r--r-xr--
chmod 455: -r--r-xr-x
chmod 456: -r--r-xrw-
chmod 457: -r--r-xrwx
chmod 460: -r--rw----
chmod 461: -r--rw---x
chmod 462: -r--rw--w-
chmod 463: -r--rw--wx
chmod 464: -r--rw-r--
chmod 465: -r--rw-r-x
chmod 466: -r--rw-rw-
chmod 467: -r--rw-rwx
chmod 470: -r--rwx---
chmod 471: -r--rwx--x
chmod 472: -r--rwx-w-
chmod 473: -r--rwx-wx
chmod 474: -r--rwxr--
chmod 475: -r--rwxr-x
chmod 476: -r--rwxrw-
chmod 477: -r--rwxrwx
chmod 500: -r-x------
chmod 501: -r-x-----x
chmod 502: -r-x----w-
chmod 503: -r-x----wx
chmod 504: -r-x---r--
chmod 505: -r-x---r-x
chmod 506: -r-x---rw-
chmod 507: -r-x---rwx
chmod 510: -r-x--x---
chmod 511: -r-x--x--x
chmod 512: -r-x--x-w-
chmod 513: -r-x--x-wx
chmod 514: -r-x--xr--
chmod 515: -r-x--xr-x
chmod 516: -r-x--xrw-
chmod 517: -r-x--xrwx
chmod 520: -r-x-w----
chmod 521: -r-x-w---x
chmod 522: -r-x-w--w-
chmod 523: -r-x-w--wx
chmod 524: -r-x-w-r--
chmod 525: -r-x-w-r-x
chmod 526: -r-x-w-rw-
chmod 527: -r-x-w-rwx
chmod 530: -r-x-wx---
chmod 531: -r-x-wx--x
chmod 532: -r-x-wx-w-
chmod 533: -r-x-wx-wx
chmod 534: -r-x-wxr--
chmod 535: -r-x-wxr-x
chmod 536: -r-x-wxrw-
chmod 537: -r-x-wxrwx
chmod 540: -r-xr-----
chmod 541: -r-xr----x
chmod 542: -r-xr---w-
chmod 543: -r-xr---wx
chmod 544: -r-xr--r--
chmod 545: -r-xr--r-x
chmod 546: -r-xr--rw-
chmod 547: -r-xr--rwx
chmod 550: -r-xr-x---
chmod 551: -r-xr-x--x
chmod 552: -r-xr-x-w-
chmod 553: -r-xr-x-wx
chmod 554: -r-xr-xr--
chmod 555: -r-xr-xr-x
chmod 556: -r-xr-xrw-
chmod 557: -r-xr-xrwx
chmod 560: -r-xrw----
chmod 561: -r-xrw---x
chmod 562: -r-xrw--w-
chmod 563: -r-xrw--wx
chmod 564: -r-xrw-r--
chmod 565: -r-xrw-r-x
chmod 566: -r-xrw-rw-
chmod 567: -r-xrw-rwx
chmod 570: -r-xrwx---
chmod 571: -r-xrwx--x
chmod 572: -r-xrwx-w-
chmod 573: -r-xrwx-wx
chmod 574: -r-xrwxr--
chmod 575: -r-xrwxr-x
chmod 576: -r-xrwxrw-
chmod 577: -r-xrwxrwx
chmod 600: -rw-------
chmod 601: -rw------x
chmod 602: -rw-----w-
chmod 603: -rw-----wx
chmod 604: -rw----r--
chmod 605: -rw----r-x
chmod 606: -rw----rw-
chmod 607: -rw----rwx
chmod 610: -rw---x---
chmod 611: -rw---x--x
chmod 612: -rw---x-w-
chmod 613: -rw---x-wx
chmod 614: -rw---xr--
chmod 615: -rw---xr-x
chmod 616: -rw---xrw-
chmod 617: -rw---xrwx
chmod 620: -rw--w----
chmod 621: -rw--w---x
chmod 622: -rw--w--w-
chmod 623: -rw--w--wx
chmod 624: -rw--w-r--
chmod 625: -rw--w-r-x
chmod 626: -rw--w-rw-
chmod 627: -rw--w-rwx
chmod 630: -rw--wx---
chmod 631: -rw--wx--x
chmod 632: -rw--wx-w-
chmod 633: -rw--wx-wx
chmod 634: -rw--wxr--
chmod 635: -rw--wxr-x
chmod 636: -rw--wxrw-
chmod 637: -rw--wxrwx
chmod 640: -rw-r-----
chmod 641: -rw-r----x
chmod 642: -rw-r---w-
chmod 643: -rw-r---wx
chmod 644: -rw-r--r--
chmod 645: -rw-r--r-x
chmod 646: -rw-r--rw-
chmod 647: -rw-r--rwx
chmod 650: -rw-r-x---
chmod 651: -rw-r-x--x
chmod 652: -rw-r-x-w-
chmod 653: -rw-r-x-wx
chmod 654: -rw-r-xr--
chmod 655: -rw-r-xr-x
chmod 656: -rw-r-xrw-
chmod 657: -rw-r-xrwx
chmod 660: -rw-rw----
chmod 661: -rw-rw---x
chmod 662: -rw-rw--w-
chmod 663: -rw-rw--wx
chmod 664: -rw-rw-r--
chmod 665: -rw-rw-r-x
chmod 666: -rw-rw-rw-
chmod 667: -rw-rw-rwx
chmod 670: -rw-rwx---
chmod 671: -rw-rwx--x
chmod 672: -rw-rwx-w-
chmod 673: -rw-rwx-wx
chmod 674: -rw-rwxr--
chmod 675: -rw-rwxr-x
chmod 676: -rw-rwxrw-
chmod 677: -rw-rwxrwx
chmod 700: -rwx------
chmod 701: -rwx-----x
chmod 702: -rwx----w-
chmod 703: -rwx----wx
chmod 704: -rwx---r--
chmod 705: -rwx---r-x
chmod 706: -rwx---rw-
chmod 707: -rwx---rwx
chmod 710: -rwx--x---
chmod 711: -rwx--x--x
chmod 712: -rwx--x-w-
chmod 713: -rwx--x-wx
chmod 714: -rwx--xr--
chmod 715: -rwx--xr-x
chmod 716: -rwx--xrw-
chmod 717: -rwx--xrwx
chmod 720: -rwx-w----
chmod 721: -rwx-w---x
chmod 722: -rwx-w--w-
chmod 723: -rwx-w--wx
chmod 724: -rwx-w-r--
chmod 725: -rwx-w-r-x
chmod 726: -rwx-w-rw-
chmod 727: -rwx-w-rwx
chmod 730: -rwx-wx---
chmod 731: -rwx-wx--x
chmod 732: -rwx-wx-w-
chmod 733: -rwx-wx-wx
chmod 734: -rwx-wxr--
chmod 735: -rwx-wxr-x
chmod 736: -rwx-wxrw-
chmod 737: -rwx-wxrwx
chmod 740: -rwxr-----
chmod 741: -rwxr----x
chmod 742: -rwxr---w-
chmod 743: -rwxr---wx
chmod 744: -rwxr--r--
chmod 745: -rwxr--r-x
chmod 746: -rwxr--rw-
chmod 747: -rwxr--rwx
chmod 750: -rwxr-x---
chmod 751: -rwxr-x--x
chmod 752: -rwxr-x-w-
chmod 753: -rwxr-x-wx
chmod 754: -rwxr-xr--
chmod 755: -rwxr-xr-x
chmod 756: -rwxr-xrw-
chmod 757: -rwxr-xrwx
chmod 760: -rwxrw----
chmod 761: -rwxrw---x
chmod 762: -rwxrw--w-
chmod 763: -rwxrw--wx
chmod 764: -rwxrw-r--
chmod 765: -rwxrw-r-x
chmod 766: -rwxrw-rw-
chmod 767: -rwxrw-rwx
chmod 770: -rwxrwx---
chmod 771: -rwxrwx--x
chmod 772: -rwxrwx-w-
chmod 773: -rwxrwx-wx
chmod 774: -rwxrwxr--
chmod 775: -rwxrwxr-x
chmod 776: -rwxrwxrw-
chmod 777: -rwxrwxrwx

Congratulations!

Here's my custom stat function, which I am definately not finished with, so check back in a couple days and if you find any improvements please hook me up with a comment!

function askapache_stat( $filename ) {
$p=@fileperms($filename);
$s=@stat($filename);
$str='';
$t=decoct($s['mode'] & 0170000);
 
switch (octdec($t)) {
case 0140000: $str = 's'; $stat['type']='socket'; break;
case 0120000: $str = 'l'; $stat['type']='link'; break;
case 0100000: $str = '-'; $stat['type']='file'; break;
case 0060000: $str = 'b'; $stat['type']='block'; break;
case 0040000: $str = 'd'; $stat['type']='dir'; break;
case 0020000: $str = 'c'; $stat['type']='char'; break;
case 0010000: $str = 'p'; $stat['type']='fifo'; break;
default: $str = 'u'; $stat['type']='unknown'; break;
}
 
$stat['type_octal'] = sprintf("%07o", octdec($t));
 
$str .= (($p&0x0100)?'r':'-').(($p&0x0080)?'w':'-').(($p&0x0040)?(($p&0x0800)?'s':'x'):(($p&0x0800)?'S':'-'));
$str .= (($p&0x0020)?'r':'-').(($p&0x0010)?'w':'-').(($p&0x0008)?(($p&0x0400)?'s':'x'):(($p&0x0400)?'S':'-'));
$str .= (($p&0x0004)?'r':'-').(($p&0x0002)?'w':'-').(($p&0x0001)?(($p&0x0200)?'t':'x'):(($p&0x0200)?'T':'-'));
 
$stat['default_umask']=sprintf("%04o",umask());
$stat['perm_human']=$str;
$stat['perm_octal1'] = sprintf( "%o", ( $s['mode'] & 00777 ) );
$stat['perm_octal2'] = sprintf("0%o", 0777 & $p);
$stat['perm_dec'] = sprintf("%04o", $p);
$stat['perm_mode']=$s['mode'];   // File mode.
 
$stat['file'] = @realpath($filename);
$stat['basename'] = basename( $filename );
 
$stat['user_id'] = $s['uid'];
$stat['group_id'] = $s['gid'];
 
$stat['device']=$s['dev'];      // Device
$stat['device_number']=$s['rdev'];    // Device number, if device.
$stat['inode']=$s['ino'];      // File serial number
$stat['link_count']=$s['nlink'];    // link count
if($stat['type']=='link')$stat['link_to']=@readlink( $filename );
 
$stat['size']=$s['size'];    // Size of file, in bytes.
$stat['block_size']=$s['blksize'];  // Optimal block size for I/O.
$stat['blocks']=$s['blocks'];  // Number 512-byte blocks allocated
 
$stat['time_access']=@date( 'Y M D H:i:s',$s['atime']);    // Time of last access.
$stat['time_modified']=@date( 'Y M D H:i:s',$s['mtime']);    // Time of last modification
$stat['time_created']=@date( 'Y M D H:i:s',$s['ctime']);    // Time of last status change
 
clearstatcache();
return $stat;
}
 
header('Content-Type: text/plain');
$stat=askapache_stat(__FILE__);
print_r($stat);

Defining Permission Bits

!defined('S_IFMT') && define('S_IFMT', 0170000); //  mask for all types
!defined('S_IFSOCK') && define('S_IFSOCK', 0140000); // type: socket
!defined('S_IFLNK') && define('S_IFLNK', 0120000); // type:  symbolic link
!defined('S_IFREG') && define('S_IFREG', 0100000); // type:  regular file
!defined('S_IFBLK') && define('S_IFBLK', 0060000); // type:  block device
!defined('S_IFDIR') && define('S_IFDIR', 0040000); // type:  directory
!defined('S_IFCHR') && define('S_IFCHR', 0020000); // type:  character device
!defined('S_IFIFO') && define('S_IFIFO', 0010000); // type:  fifo
 
!defined('S_ISUID') && define('S_ISUID', 0004000); // set-uid bit
!defined('S_ISGID') && define('S_ISGID', 0002000); // set-gid bit
!defined('S_ISVTX') && define('S_ISVTX', 0001000); // sticky bit
!defined('S_IRWXU') && define('S_IRWXU', 00700); //  mask for owner permissions
!defined('S_IRUSR') && define('S_IRUSR', 00400); //  owner: read permission
!defined('S_IWUSR') && define('S_IWUSR', 00200); //  owner: write permission
!defined('S_IXUSR') && define('S_IXUSR', 00100); //  owner: execute permission
!defined('S_IRWXG') && define('S_IRWXG', 00070); //  mask for group permissions
!defined('S_IRGRP') && define('S_IRGRP', 00040); //  group: read permission
!defined('S_IWGRP') && define('S_IWGRP', 00020); //  group: write permission
!defined('S_IXGRP') && define('S_IXGRP', 00010); //  group: execute permission
!defined('S_IRWXO') && define('S_IRWXO', 00007); //  mask for others permissions
!defined('S_IROTH') && define('S_IROTH', 00004); //  others:  read permission
!defined('S_IWOTH') && define('S_IWOTH', 00002); //  others:  write permission
!defined('S_IXOTH') && define('S_IXOTH', 00001); //  others:  execute permission
 
!defined('S_IRWXUGO') && define('S_IRWXUGO', (S_IRWXU | S_IRWXG | S_IRWXO));
!defined('S_IALLUGO') && define('S_IALLUGO', (S_ISUID | S_ISGID | S_ISVTX | S_IRWXUGO));
!defined('S_IRUGO') && define('S_IRUGO', (S_IRUSR | S_IRGRP | S_IROTH));
!defined('S_IWUGO') && define('S_IWUGO', (S_IWUSR | S_IWGRP | S_IWOTH));
!defined('S_IXUGO') && define('S_IXUGO', (S_IXUSR | S_IXGRP | S_IXOTH));
!defined('S_IRWUGO') && define('S_IRWUGO', (S_IRUGO | S_IWUGO));

How File Permissions Work

When PHP is installed on your server by you or whoever runs the server, it uses the file permissions that are used by the Operating System running the server.. If you are smart or just lucky than you are running some type of BSD/Unix/Solaris/Linux/Sun based Operating system and PHP won't have any problems. If you are running on a Locked, proprietary OS like Windows, PHP will still work but it has to use a lot of shortcuts and hacks to basically "Pretend" to act like the OS is BSD/Unix, and some key features just won't be available.

The OS Permission Bits

Here's the file permissions my Linux server uses, and which PHP automatically uses. The code basically just defines the default permissions for files, and defines the file atributes for each file that you can access by using the stat function, which I've improved upon to make things easier.

Download: POSIX Standard: 5.6 File Characteristicssys/stat.h

Protection bits for File Owner

#define S_IRWXU 00700
#define S_IRUSR 00400
#define S_IWUSR 00200
#define S_IXUSR 00100

Protection bits for File Group

#define S_IRWXG 00070
#define S_IRGRP 00040
#define S_IWGRP 00020
#define S_IXGRP 00010

Protection bits for All Others

#define S_IRWXO 00007
#define S_IROTH 00004
#define S_IWOTH 00002
#define S_IXOTH 00001

Some Example Permissions

0477 // owner has read only, other and group has rwx 0677 // owner has rw only, other and group has rwx

0444 // all have read only 0666 // all have rw only

0400 // owner has read only, group and others have no permission 0600 // owner has rw only, group and others have no permission

0470 // owner has read only, group has rwx, others have no permission 0407 // owner has read only, other has rwx, group has no permission

0670 // owner has rw only, group has rwx, others have no permission 0607 // owner has rw only, group has no permission and others have rwx

What's a File

A file is not merely its contents, a name, and a file type. A file also has an owner (a user ID), a group (a group ID), permissions (what the owner can do with the file, what people in the group can do, and what everyone else can do), various timestamps, and other information. Collectively, we call these a file's attributes.

Structure of File Mode Bits

The file mode bits have two parts: the file permission bits, which control ordinary access to the file, and special mode bits, which affect only some files.

There are three kinds of permissions that a user can have for a file:

permission to read the file. For directories, this means permission to list the contents of the directory.
permission to write to (change) the file. For directories, this means permission to create and remove files in the directory.
permission to execute the file (run it as a program). For directories, this means permission to access files in the directory.

There are three categories of users who may have different permissions to perform any of the above operations on a file:

the file's owner.
other users who are in the file's group
everyone else.

Files are given an owner and group when they are created. Usually the owner is the current user and the group is the group of the directory the file is in, but this varies with the operating system, the file system the file is created on, and the way the file is created. You can change the owner and group of a file by using the chown and chgrp commands.

In addition to the three sets of three permissions listed above, the file mode bits have three special components, which affect only executable files (programs) and, on most systems, directories:

Set the process's effective user ID to that of the file upon execution (called the set-user-ID bit, or sometimes the setuid bit). For directories on a few systems, give files created in the directory the same owner as the directory, no matter who creates them, and set the set-user-ID bit of newly-created subdirectories.
Set the process's effective group ID to that of the file upon execution (called the set-group-ID bit, or sometimes the setgid bit). For directories on most systems, give files created in the directory the same group as the directory, no matter what group the user who creates them is in, and set the set-group-ID bit of newly-created subdirectories.
Prevent unprivileged users from removing or renaming a file in a directory unless they own the file or the directory; this is called the restricted deletion flag for the directory, and is commonly found on world-writable directories like /tmp.

For regular files on some older systems, save the program's text image on the swap device so it will load more quickly when run; this is called the sticky bit.

Setting Permissions

The basic symbolic operations on a file's permissions are adding, removing, and setting the permission that certain users have to read, write, and execute or search the file. These operations have the following format:

users operation permissions

The spaces between the three parts above are shown for readability only; symbolic modes cannot contain spaces. The users part tells which users' access to the file is changed. It consists of one or more of the following letters (or it can be empty). When more than one of these letters is given, the order that they are in does not matter.

u - the user who owns the file.
g - other users who are in the file's group.
o - all other users.
a - all users; the same as ugo.

The operation part tells how to change the affected users' access to the file, and is one of the following symbols:

+ - to add the permissions to whatever permissions the users already have for the file.
- - to remove the permissions from whatever permissions the users already have for the file.
= - to make the permissions the only permissions that the users have for the file.

The permissions part tells what kind of access to the file should be changed; it is normally zero or more of the following letters. As with the users part, the order does not matter when more than one letter is given. Omitting the permissions part is useful only with the = operation, where it gives the specified users no access at all to the file.

r - the permission the users have to read the file.
w - the permission the users have to write to the file.
x - the permission the users have to execute the file, or search it if it is a directory.

For example, to give everyone permission to read and write a regular file, but not to execute it, use:

a=rw

To remove write permission for all users other than the file's owner, use:

go-w

The above command does not affect the access that the owner of the file has to it, nor does it affect whether other users can read or execute the file.

To give everyone except a file's owner no permission to do anything with that file, use the mode below. Other users could still remove the file, if they have write permission on the directory it is in.

go=

Another way to specify the same thing is:

og-rwx

Copying Existing Permissions

You can base a file's permissions on its existing permissions. To do this, instead of using a series of r, w, or x letters after the operator, you use the letter u, g, or o. For example, the mode

o+g

adds the permissions for users who are in a file's group to the permissions that other users have for the file. Thus, if the file started out as mode 664 (rw-rw-r--), the above mode would change it to mode 666 (rw-rw-rw-). If the file had started out as mode 741 (rwxr----x), the above mode would change it to mode 745 (rwxr--r-x). The - and = operations work analogously.

Umask and Protection

If the users part of a symbolic mode is omitted, it defaults to a (affect all users), except that any permissions that are set in the system variable umask are not affected. The value of umask can be set using the umask command. Its default value varies from system to system.

Omitting the users part of a symbolic mode is generally not useful with operations other than +. It is useful with + because it allows you to use umask as an easily customizable protection against giving away more permission to files than you intended to. As an example, if umask has the value 2, which removes write permission for users who are not in the file's group, then the mode:

+w

adds permission to write to the file to its owner and to other users who are in the file's group, but not to other users. In contrast, the mode:

a+w

ignores umask, and does give write permission for the file to all users.

Directories, Set-User-ID and Set-Group-ID Bits

On most systems, if a directory's set-group-ID bit is set, newly created subfiles inherit the same group as the directory, and newly created subdirectories inherit the set-group-ID bit of the parent directory. On a few systems, a directory's set-user-ID bit has a similar effect on the ownership of new subfiles and the set-user-ID bits of new subdirectories. These mechanisms let users share files more easily, by lessening the need to use chmod or chown to share new files.

These convenience mechanisms rely on the set-user-ID and set-group-ID bits of directories. If commands like chmod and mkdir routinely cleared these bits on directories, the mechanisms would be less convenient and it would be harder to share files. Therefore, a command like chmod does not affect the set-user-ID or set-group-ID bits of a directory unless the user specifically mentions them in a symbolic mode, or sets them in a numeric mode. For example, on systems that support set-group-ID inheritance:

# These commands leave the set-user-ID and
# set-group-ID bits of the subdirectories alone,
# so that they retain their default values.
mkdir A B C
chmod 755 A
chmod 0755 B
chmod u=rwx,go=rx C
mkdir -m 755 D
mkdir -m 0755 E
mkdir -m u=rwx,go=rx F

If you want to try to set these bits, you must mention them explicitly in the symbolic or numeric modes, e.g.:

# These commands try to set the set-user-ID
# and set-group-ID bits of the subdirectories.
mkdir G H
chmod 6755 G
chmod u=rwx,go=rx,a+s H
mkdir -m 6755 I
mkdir -m u=rwx,go=rx,a+s J

If you want to try to clear these bits, you must mention them explicitly in a symbolic mode, e.g.:

# This command tries to clear the set-user-ID
# and set-group-ID bits of the directory D.
chmod a-s D

Numeric Modes

The permissions granted to the user, to other users in the file's group, and to other users not in the file's group each require three bits, which are represented as one octal digit. The three special mode bits also require one bit each, and they are as a group represented as another octal digit. Here is how the bits are arranged, starting with the lowest valued bit:

Other users not in the file's group:

1 Execute/search
2 Write
4 Read

Other users in the file's group:

10 Execute/search
20 Write
40 Read

The file's owner:

100 Execute/search
200 Write
400 Read

Special mode bits:

1000 Restricted deletion flag or sticky bit
2000 Set group ID on execution
4000 Set user ID on execution

For example, numeric mode 4755 corresponds to symbolic mode u=rwxs,go=rx, and numeric mode 664 corresponds to symbolic mode ug=rw,o=r. Numeric mode 0 corresponds to symbolic mode a=.

Apache's Internal Bits (hex)

#define APR_FPROT_USETID   0x8000 /* Set user id */
#define APR_FPROT_UREAD   0x0400 /* Read by user */
#define APR_FPROT_UWRITE   0x0200 /* Write by user */
#define APR_FPROT_UEXECUTE 0x0100 /* Execute by user */
 
#define APR_FPROT_GSETID   0x4000 /* Set group id */
#define APR_FPROT_GREAD   0x0040 /* Read by group */
#define APR_FPROT_GWRITE   0x0020 /* Write by group */
#define APR_FPROT_GEXECUTE 0x0010 /* Execute by group */
 
#define APR_FPROT_WSTICKY 0x2000 /* Sticky bit */
#define APR_FPROT_WREAD   0x0004 /* Read by others */
#define APR_FPROT_WWRITE 0x0002 /* Write by others */
#define APR_FPROT_WEXECUTE 0x0001 /* Execute by others */
 
#define APR_FPROT_OS_DEFAULT  0x0FFF /* use OS's default permissions */
 
/* additional permission flags for apr_file_copy  and apr_file_append */
#define APR_FPROT_FILE_SOURCE_PERMS 0x1000 /* Copy source file's permissions */

Download: httpd-2.2.10/srclib/apr/file_io/unix/fileacc.c Here's some interesting bitmasking done by Apache that uses the defined bits set earlier by stat.h

apr_unix_perms2mode(perms){
 mode=0;
 if (perms & APR_USETID) mode |= S_ISUID;
 if (perms & APR_UREAD)  mode |= S_IRUSR;
 if (perms & APR_UWRITE) mode |= S_IWUSR;
 if (perms & APR_UEXECUTE) mode |= S_IXUSR;
 
 if (perms & APR_GSETID) mode |= S_ISGID;
 if (perms & APR_GREAD)  mode |= S_IRGRP;
 if (perms & APR_GWRITE) mode |= S_IWGRP;
 if (perms & APR_GEXECUTE) mode |= S_IXGRP;
 
 if (perms & APR_WSTICKY) mode |= S_ISVTX;
 if (perms & APR_WREAD)  mode |= S_IROTH;
 if (perms & APR_WWRITE) mode |= S_IWOTH;
 if (perms & APR_WEXECUTE) mode |= S_IXOTH;
 return mode;
}
 
apr_unix_mode2perms(mode){
 perms = 0;
 if (mode & S_ISUID)perms |= APR_USETID;
 if (mode & S_IRUSR)perms |= APR_UREAD;
 if (mode & S_IWUSR)perms |= APR_UWRITE;
 if (mode & S_IXUSR)perms |= APR_UEXECUTE;
 
 if (mode & S_ISGID)perms |= APR_GSETID;
 if (mode & S_IRGRP)perms |= APR_GREAD;
 if (mode & S_IWGRP)perms |= APR_GWRITE;
 if (mode & S_IXGRP)perms |= APR_GEXECUTE;
 
 if (mode & S_ISVTX)perms |= APR_WSTICKY;
 if (mode & S_IROTH)perms |= APR_WREAD;
 if (mode & S_IWOTH)perms |= APR_WWRITE;
 if (mode & S_IXOTH)perms |= APR_WEXECUTE;
 return perms;
}

umask

umask(int mask){
 arg1;
 int oldumask;
 int arg_count = ZEND_NUM_ARGS();
 oldumask = umask(077);
 
 if (BG(umask) == -1) BG(umask) = oldumask;
 if (arg_count == 0) umask(oldumask);
 
 convert_to_long_ex(arg1);
 umask(Z_LVAL_PP(arg1));
 RETURN_LONG(oldumask);
}

File Attributes

Each file will have attributes based on the type of OS.. Using the stat command you can view them.

Viewing stat results

* %a - Access rights in octal
* %A - Access rights in human readable form
* %b - Number of blocks allocated (see %B)
* %B - The size in bytes of each block reported by %b
* %d - Device number in decimal
* %D - Device number in hex
* %f - Raw mode in hex
* %F - File type
* %g - Group ID of owner
* %G - Group name of owner
* %h - Number of hard links
* %i - Inode number
* %n - File name
* %N - Quoted file name with dereference if symbolic link
* %o - I/O block size
* %s - Total size, in bytes
* %t - Major device type in hex
* %T - Minor device type in hex
* %u - User ID of owner
* %U - User name of owner
* %x - Time of last access
* %X - Time of last access as seconds since Epoch
* %y - Time of last modification
* %Y - Time of last modification as seconds since Epoch
* %z - Time of last change
* %Z - Time of last change as seconds since Epoch

The OS Attribute Bits

These defined values are what allows your operating system to determine the type of file being accessed.

#define S_IFMT   00170000  /* These bits determine file type. */
#define S_IFSOCK 0140000  /* Socket file */
#define S_IFLNK   0120000  /* Symbolic Link */
#define S_IFREG   0100000  /* Regular file */
#define S_IFDIR   0040000  /* Directory */
#define S_IFIFO  0010000   /* FIFO first-in-first-out file */
 
/* Such devices can be read either a character at a time or a "block" (many characters) at a time,
hence we say there are block special files and character special files. */
#define S_IFBLK   0060000  /* Block device */
#define S_IFCHR  0020000  /* Character device */

Special Permission Bits

#define S_ISUID  0004000  /* Set user ID on execution.  */
#define S_ISGID  0002000  /* Set group ID on execution.  */
#define S_ISVTX  0001000 /* Save swapped text after use (sticky).  */

Bitmasking to determine Filetype

#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
#define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
#define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
#define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)

Default Permission Masks

#define S_IRWXUGO (S_IRWXU|S_IRWXG|S_IRWXO)
#define S_IALLUGO (S_ISUID|S_ISGID|S_ISVTX|S_IRWXUGO)
#define S_IRUGO  (S_IRUSR|S_IRGRP|S_IROTH)
#define S_IWUGO  (S_IWUSR|S_IWGRP|S_IWOTH)
#define S_IXUGO  (S_IXUSR|S_IXGRP|S_IXOTH)

Download: httpd-2.2.10/srclib/apr/file_io/unix/filestat.c, this file shows a simple way to determine the type of file.

filetype_from_mode(mode){
 type;
 switch (mode & S_IFMT) {
  case S_IFREG:  type = APR_REG;  break;
  case S_IFDIR:  type = APR_DIR;  break;
  case S_IFLNK:  type = APR_LNK;  break;
 
  case S_IFCHR:  type = APR_CHR;  break;
  case S_IFBLK:  type = APR_BLK;  break;
  case S_IFFIFO: type = APR_PIPE; break;
  case S_IFSOCK: type = APR_SOCK; break;
  default: type = APR_UNKFILE;
 }
 return type;
}

Apache Stat Bits

#define APR_FINFO_LINK  0x00000001 /* Stat the link not the file itself if it is a link */
#define APR_FINFO_MTIME  0x00000010 /* Modification Time */
#define APR_FINFO_CTIME  0x00000020 /* Creation or inode-changed time */
#define APR_FINFO_ATIME  0x00000040 /* Access Time */
#define APR_FINFO_SIZE  0x00000100 /* Size of the file */
#define APR_FINFO_CSIZE  0x00000200 /* Storage size consumed by the file */
#define APR_FINFO_DEV  0x00001000 /* Device */
#define APR_FINFO_INODE  0x00002000 /* Inode */
#define APR_FINFO_NLINK  0x00004000 /* Number of links */
#define APR_FINFO_TYPE  0x00008000 /* Type */
#define APR_FINFO_USER  0x00010000 /* User */
#define APR_FINFO_GROUP  0x00020000 /* Group */
#define APR_FINFO_UPROT  0x00100000 /* User protection bits */
#define APR_FINFO_GPROT  0x00200000 /* Group protection bits */
#define APR_FINFO_WPROT  0x00400000 /* World protection bits */
#define APR_FINFO_ICASE  0x01000000 /* if dev is case insensitive */
#define APR_FINFO_NAME  0x02000000 /* name in proper case */
#define APR_FINFO_MIN  0x00008170 /* type, mtime, ctime, atime, size */
#define APR_FINFO_IDENT  0x00003000 /* dev and inode */
#define APR_FINFO_OWNER  0x00030000 /* user and group */
#define APR_FINFO_PROT  0x00700000 /* all protections */
#define APR_FINFO_NORM  0x0073b170 /* an atomic unix apr_stat() */
#define APR_FINFO_DIRENT 0x02000000 /* an atomic unix apr_dir_read() */

The Apache file information structure.

apr_uid_t user;  /* The user id that owns the file */
apr_gid_t group;  /* The group id that owns the file */
apr_ino_t inode; /* The inode of the file. */
apr_dev_t device; /* The id of the device the file is on. */
apr_int32_t nlink; /* The number of hard links to the file. */
apr_off_t size;  /* The size of the file */
apr_off_t csize; /* The storage size consumed by the file */
apr_time_t atime; /* The time the file was last accessed */
apr_time_t mtime; /* The time the file was last modified */
apr_time_t ctime; /* The time the file was created, or the inode was last changed */
const char *fname; /* The pathname of the file (possibly unrooted) */
const char *name; /* The file's name (no path) in filesystem case */

File Time Attributes

touch
If changing both the access and modification times to the current time, touch can change the timestamps for files that the user running it does not own but has write permission for. Otherwise, the user must own the files.

Although touch provides options for changing two of the times the times of last access and modification of a file, there is actually a third one as well: the inode change time. This is often referred to as a file's ctime. The inode change time represents the time when the file's meta-information last changed. One common example of this is when the permissions of a file change. Changing the permissions doesn't access the file, so the atime doesn't change, nor does it modify the file, so the mtime doesn't change. Yet, something about the file itself has changed, and this must be noted somewhere. This is the job of the ctime field. This is necessary, so that, for example, a backup program can make a fresh copy of the file, including the new permissions value. Another operation that modifies a file's ctime without affecting the others is renaming. In any case, it is not possible, in normal operations, for a user to change the ctime field to a user-specified value.

WebHost allows you to create multiple users per account. Each user can have domain assigned to its home home directory accessible via FTP or SSH/SCP. The problem with multiple users on the same account is that they share the same default unix group, and default permissions allow their files to be easily modified by the members of this group. Usually this doesn't pose a problem as each user is probably trusted by account owner to not to mess with others files, but if one of the users have their web application hacked then all other users on the same account will be in danger.

By default all files in your account are created with 644 privileges and directories are with 775. That means any user can read your files and any user from the same account can move and add files in your freshly made directories. Your home directory is different, though. By default it carries 751 attribute meaning that only members of your group can see your files, but can't add any new. These group access schemes are possible, because every user in your account has its primary/default group set to "pgxxxxxx", which is assigned to every new file you create by default. The normal way to secure users from web-intrusion is to assign a separate group to the web-server user, removing it from default group. This way, exploited scripts will not be able to traverse into home directories of other users on your account. To allow account users to update centralized web-site they could be added to web-site group explicitly. But this "normal way" doesn't work with DreamHost, because you can't delete web-user from the default group and unless you set access for every new file explicitly, it will be possible for an intruder to read it.

To make managing privileges easier in interactive sessions "umask 007" command can be specified in your .bash_profile - this makes all new files carry xx0 mask. You also need to control your scripts (web based or cron/shell) so that they set mask for critical files explicitly. To secure account users from access by means of hacked user script you would also like to define another group for every user in your account and change group ownership of the user's home directory to that group with "set gid" bit set (and optional umask 007 in .bash_profile).

Therefore, to secure your users from web-intrusion you need to:

Add a separate user and group for every domain where apache will be running
Add a separate group for other user accounts
Change the default group for new files created by your users by changing the group of their home directory and setting "set gid" bit for it (it is impossible to do this with FTP accounts, therefore you will need to login in each account via SSH)
Add users who need access to web-site into the web-user group
Optionally set umask 007 in .bash_profile for every user to tweak default WebHost775/664 permissions to something like 770/660 for directories and files that are not meant to be read by Apache (660 could also be used for all web scripts including .php as they are not read by dhapache CGI, but merely executed)

Apache Security

All your web files that need to be read by Apache should be readable by everyone as Apache itself is run under dhapache user. However, executable scripts like .php are executed under your own user and do not have to be world readable as they are not actually read by Apache, but executed via suEXEC. Quite the opposite - to prevent your code or database settings from being messed by any third-parties you SHOULD set permissions to these files explicitly to something like 640 or even 600 depending on who do you trust.

Multiuser security setup example

For our example, we will create a rainforce_www user and a aapp_www group for serving web files with apache and setup a rainforce user with a 'aapp group to manage mail and keep other files on DH privately. Since these records already exist, you will need to subsitute your own names.

Login to create the users rainforce_www and rainforce with shell access.
Create two groups - aapp_www and aapp. Note that users created in previous step are still members of the same default pgxxxxxx group.
Add rainforce_www to 'the 'aapp_www group and rainforce to both the aapp_www and aapp groups
Move your domain to rainforce_www account (mine is rainforce.org)
Now login to SSH with your rainforce_www user and change the default group for your home directory with "sgid" bit set to make all current and new files/directories created in this directory have the same aapp_www group.

 $ chgrp -R aapp_www .
 $ chmod 2751 .
 $ chmod 2771 rainforce.org

By setting 2771 the directory will be writable by the owner, the group and will be only executable by others. The contents of an executable only directory cannot be listed, but the files inside it can be read (if the permissions of the file allow it). It is important that the directory can be executable in order to allow static content (e.g. .html files) inside it to be read. Remember that directories you don't want anyone to have web access to, should be 0770 (writable by the owner and group, or 0750 writable by the owner and readable by group). Such strict permissions should by applied to password files, php include files or databases files (such as SQLite, BDB, etc).

Do the same for rainforce user, but specify aapp group instead.

 $ chgrp -R aapp .
 $ chmod 2751 .

Optionally modify umask in .bash_profile in user's home to 007 to make all files created by this user have 660 permissions set by default. If you want that newly created files by accessible by the web, you need to manually setup it's permissions to 664.

Now I can login as the user "rainforce" and update the web-site in the ../rainforce_www/rainforce.org directory. There is one more setup needed. Because files copied from other accounts can have 644 permissions set instead of 664, you need a script which will update permissions to 664 or 660 to allow other group members modify such files.

SSH key fingerprints

Just gen your own I guess

External Links

Original Article from DreamHost Wiki

Content is available under GNU Free Documentation License 1.2.

Example File Permission Bits

`/usr/lib/w3m/cgi-bin/dirlist.cgi`

sub utype {
  local($_) = @_;
  local(%T) = (
    0010000, 'PIPE',
    0020000, 'CHR',
    0040000, 'DIR',
    0060000, 'BLK',
    0100000, 'FILE',
    0120000, 'LINK',
    0140000, 'SOCK',
  );
  return $T{($_ & 0170000)} || 'FILE';
}
 
sub umode {
  local($_) = @_;
  local(%T) = (
    0010000, 'p',
    0020000, 'c',
    0040000, 'd',
    0060000, 'b',
    0100000, '-',
    0120000, 'l',
    0140000, 's',
  );
 
  return ($T{($_ & 0170000)} || '-')
     . (($_ & 00400) ? 'r' : '-')
     . (($_ & 00200) ? 'w' : '-')
     . (($_ & 04000) ? 's' :
       (($_ & 00100) ? 'x' : '-'))
     . (($_ & 00040) ? 'r' : '-')
     . (($_ & 00020) ? 'w' : '-')
     . (($_ & 02000) ? 's' :
       (($_ & 00010) ? 'x' : '-'))
     . (($_ & 00004) ? 'r' : '-')
     . (($_ & 00002) ? 'w' : '-')
     . (($_ & 01000) ? 't' :
       (($_ & 00001) ? 'x' : '-'));
}

`/usr/lib/perl/5.8.4/linux/stat.ph`

        eval 'sub S_IFMT () {00170000;}' unless defined(&S_IFMT);
        eval 'sub S_IFSOCK () {0140000;}' unless defined(&S_IFSOCK);
        eval 'sub S_IFLNK () {0120000;}' unless defined(&S_IFLNK);
        eval 'sub S_IFREG () {0100000;}' unless defined(&S_IFREG);
        eval 'sub S_IFBLK () {0060000;}' unless defined(&S_IFBLK);
        eval 'sub S_IFDIR () {0040000;}' unless defined(&S_IFDIR);
        eval 'sub S_IFCHR () {0020000;}' unless defined(&S_IFCHR);
        eval 'sub S_IFIFO () {0010000;}' unless defined(&S_IFIFO);
        eval 'sub S_ISUID () {0004000;}' unless defined(&S_ISUID);
        eval 'sub S_ISGID () {0002000;}' unless defined(&S_ISGID);
        eval 'sub S_ISVTX () {0001000;}' unless defined(&S_ISVTX);
        eval 'sub S_ISLNK {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFLNK));
        }' unless defined(&S_ISLNK);
        eval 'sub S_ISREG {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFREG));
        }' unless defined(&S_ISREG);
        eval 'sub S_ISDIR {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFDIR));
        }' unless defined(&S_ISDIR);
        eval 'sub S_ISCHR {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFCHR));
        }' unless defined(&S_ISCHR);
        eval 'sub S_ISBLK {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFBLK));
        }' unless defined(&S_ISBLK);
        eval 'sub S_ISFIFO {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFIFO));
        }' unless defined(&S_ISFIFO);
        eval 'sub S_ISSOCK {
            local($m) = @_;
            eval q(((($m) &  &S_IFMT) ==  &S_IFSOCK));
        }' unless defined(&S_ISSOCK);
        eval 'sub S_IRWXU () {00700;}' unless defined(&S_IRWXU);
        eval 'sub S_IRUSR () {00400;}' unless defined(&S_IRUSR);
        eval 'sub S_IWUSR () {00200;}' unless defined(&S_IWUSR);
        eval 'sub S_IXUSR () {00100;}' unless defined(&S_IXUSR);
        eval 'sub S_IRWXG () {00070;}' unless defined(&S_IRWXG);
        eval 'sub S_IRGRP () {00040;}' unless defined(&S_IRGRP);
        eval 'sub S_IWGRP () {00020;}' unless defined(&S_IWGRP);
        eval 'sub S_IXGRP () {00010;}' unless defined(&S_IXGRP);
        eval 'sub S_IRWXO () {00007;}' unless defined(&S_IRWXO);
        eval 'sub S_IROTH () {00004;}' unless defined(&S_IROTH);
        eval 'sub S_IWOTH () {00002;}' unless defined(&S_IWOTH);
        eval 'sub S_IXOTH () {00001;}' unless defined(&S_IXOTH);
    }
    if(defined(&__KERNEL__)) {
        eval 'sub S_IRWXUGO () {( &S_IRWXU| &S_IRWXG| &S_IRWXO);}' unless defined(&S_IRWXUGO);
        eval 'sub S_IALLUGO () {( &S_ISUID| &S_ISGID| &S_ISVTX| &S_IRWXUGO);}' unless defined(&S_IALLUGO);
        eval 'sub S_IRUGO () {( &S_IRUSR| &S_IRGRP| &S_IROTH);}' unless defined(&S_IRUGO);
        eval 'sub S_IWUGO () {( &S_IWUSR| &S_IWGRP| &S_IWOTH);}' unless defined(&S_IWUGO);
        eval 'sub S_IXUGO () {( &S_IXUSR| &S_IXGRP| &S_IXOTH);}' unless defined(&S_IXUGO);
        require 'linux/types.ph';
        require 'linux/time.ph';
    }

Mozilla-Source 1.8a2

/* notice that these valuse are octal. */
const PERM_IRWXU = 00700;  /* read, write, execute/search by owner */
const PERM_IRUSR = 00400;  /* read permission, owner */
const PERM_IWUSR = 00200;  /* write permission, owner */
const PERM_IXUSR = 00100;  /* execute/search permission, owner */
const PERM_IRWXG = 00070;  /* read, write, execute/search by group */
const PERM_IRGRP = 00040;  /* read permission, group */
const PERM_IWGRP = 00020;  /* write permission, group */
const PERM_IXGRP = 00010;  /* execute/search permission, group */
const PERM_IRWXO = 00007;  /* read, write, execute/search by others */
const PERM_IROTH = 00004;  /* read permission, others */
const PERM_IWOTH = 00002;  /* write permission, others */
const PERM_IXOTH = 00001;  /* execute/search permission, others */
 
const MODE_RDONLY   = 0x01;
const MODE_WRONLY   = 0x02;
const MODE_RDWR     = 0x04;
const MODE_CREATE   = 0x08;
const MODE_APPEND   = 0x10;
const MODE_TRUNCATE = 0x20;
const MODE_SYNC     = 0x40;
const MODE_EXCL     = 0x80;

`/usr/include/libpng12/png.h`

/* Transform masks for the high-level interface */
#define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
#define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
#define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
#define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
#define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
#define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
#define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
#define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
#define PNG_TRANSFORM_BGR            0x0080    /* read and write */
#define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
#define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
#define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
#define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* WRITE only */

`/usr/lib/python2.4/stat.py`

# Extract bits from the mode
 
def S_IMODE(mode):
    return mode & 07777
 
def S_IFMT(mode):
    return mode & 0170000
 
# Constants used as S_IFMT() for various file types
# (not all are implemented on all systems)
 
S_IFDIR  = 0040000
S_IFCHR  = 0020000
S_IFBLK  = 0060000
S_IFREG  = 0100000
S_IFIFO  = 0010000
S_IFLNK  = 0120000
S_IFSOCK = 0140000
 
# Functions to test for each file type
 
def S_ISDIR(mode):
    return S_IFMT(mode) == S_IFDIR
 
def S_ISCHR(mode):
    return S_IFMT(mode) == S_IFCHR
 
def S_ISBLK(mode):
    return S_IFMT(mode) == S_IFBLK
 
def S_ISREG(mode):
    return S_IFMT(mode) == S_IFREG
 
def S_ISFIFO(mode):
    return S_IFMT(mode) == S_IFIFO
 
def S_ISLNK(mode):
    return S_IFMT(mode) == S_IFLNK
 
def S_ISSOCK(mode):
    return S_IFMT(mode) == S_IFSOCK
 
# Names for permission bits
 
S_ISUID = 04000
S_ISGID = 02000
S_ENFMT = S_ISGID
S_ISVTX = 01000
S_IREAD = 00400
S_IWRITE = 00200
S_IEXEC = 00100
S_IRWXU = 00700
S_IRUSR = 00400
S_IWUSR = 00200
S_IXUSR = 00100
S_IRWXG = 00070
S_IRGRP = 00040
S_IWGRP = 00020
S_IXGRP = 00010
S_IRWXO = 00007
S_IROTH = 00004
S_IWOTH = 00002
S_IXOTH = 00001

`/usr/include/bits/stat.h`

/* Encoding of the file mode.  */
 
#define __S_IFMT        0170000 /* These bits determine file type.  */
 
/* File types.  */
#define __S_IFDIR       0040000 /* Directory.  */
#define __S_IFCHR       0020000 /* Character device.  */
#define __S_IFBLK       0060000 /* Block device.  */
#define __S_IFREG       0100000 /* Regular file.  */
#define __S_IFIFO       0010000 /* FIFO.  */
#define __S_IFLNK       0120000 /* Symbolic link.  */
#define __S_IFSOCK      0140000 /* Socket.  */
 
/* POSIX.1b objects.  Note that these macros always evaluate to zero.  But
   they do it by enforcing the correct use of the macros.  */
#define __S_TYPEISMQ(buf)  ((buf)->st_mode - (buf)->st_mode)
#define __S_TYPEISSEM(buf) ((buf)->st_mode - (buf)->st_mode)
#define __S_TYPEISSHM(buf) ((buf)->st_mode - (buf)->st_mode)
 
/* Protection bits.  */
 
#define __S_ISUID       04000   /* Set user ID on execution.  */
#define __S_ISGID       02000   /* Set group ID on execution.  */
#define __S_ISVTX       01000   /* Save swapped text after use (sticky).  */
#define __S_IREAD       0400    /* Read by owner.  */
#define __S_IWRITE      0200    /* Write by owner.  */
#define __S_IEXEC       0100    /* Execute by owner.  */

`/usr/include/linux/nfs.h`

#define NFS_FIFO_DEV    (-1)
#define NFSMODE_FMT     0170000
#define NFSMODE_DIR     0040000
#define NFSMODE_CHR     0020000
#define NFSMODE_BLK     0060000
#define NFSMODE_REG     0100000
#define NFSMODE_LNK     0120000
#define NFSMODE_SOCK    0140000
#define NFSMODE_FIFO    0010000

`/usr/include/linux/nfs3.h`

#define NFS3_FIFO_DEV           (-1)
#define NFS3MODE_FMT            0170000
#define NFS3MODE_DIR            0040000
#define NFS3MODE_CHR            0020000
#define NFS3MODE_BLK            0060000
#define NFS3MODE_REG            0100000
#define NFS3MODE_LNK            0120000
#define NFS3MODE_SOCK           0140000
#define NFS3MODE_FIFO           0010000
 
/* Flags for access() call */
#define NFS3_ACCESS_READ        0x0001
#define NFS3_ACCESS_LOOKUP      0x0002
#define NFS3_ACCESS_MODIFY      0x0004
#define NFS3_ACCESS_EXTEND      0x0008
#define NFS3_ACCESS_DELETE      0x0010
#define NFS3_ACCESS_EXECUTE     0x0020
#define NFS3_ACCESS_FULL        0x003f

`/usr/include/linux/stat.h`

#define S_IFMT  00170000
#define S_IFSOCK 0140000
#define S_IFLNK  0120000
#define S_IFREG  0100000
#define S_IFBLK  0060000
#define S_IFDIR  0040000
#define S_IFCHR  0020000
#define S_IFIFO  0010000
#define S_ISUID  0004000
#define S_ISGID  0002000
#define S_ISVTX  0001000
 
#define S_ISLNK(m)      (((m) & S_IFMT) == S_IFLNK)
#define S_ISREG(m)      (((m) & S_IFMT) == S_IFREG)
#define S_ISDIR(m)      (((m) & S_IFMT) == S_IFDIR)
#define S_ISCHR(m)      (((m) & S_IFMT) == S_IFCHR)
#define S_ISBLK(m)      (((m) & S_IFMT) == S_IFBLK)
#define S_ISFIFO(m)     (((m) & S_IFMT) == S_IFIFO)
#define S_ISSOCK(m)     (((m) & S_IFMT) == S_IFSOCK)
 
#define S_IRWXU 00700
#define S_IRUSR 00400
#define S_IWUSR 00200
#define S_IXUSR 00100
 
#define S_IRWXG 00070
#define S_IRGRP 00040
#define S_IWGRP 00020
#define S_IXGRP 00010
 
#define S_IRWXO 00007
#define S_IROTH 00004
#define S_IWOTH 00002
#define S_IXOTH 00001

Further File Permissions Reading

Related PHP Functions

Special file types

link invocation: Make a hard link via the link syscall
ln invocation: Make links between files
mkdir invocation: Make directories
mkfifo invocation: Make FIFOs (named pipes)
mknod invocation: Make block or character special files
readlink invocation: Print the referent of a symbolic link
rmdir invocation: Remove empty directories
unlink invocation: Remove files via unlink syscall

Changing file attributes

chown invocation: Change file owner and group
chgrp invocation: Change group ownership
chmod invocation: Change access permissions
touch invocation: Change file timestamps

Chmod, Umask, Stat, Fileperms, and File Permissions originally appeared on AskApache.com

Sample Page

admin- — Fri, 13 Jan 2012 23:17:45 +0000

AskApache.com

This is an example page. It's different from a blog post because it will stay in one place and will show up in your site navigation (in most themes). Most people start with an About page that introduces them to potential site visitors. It might say something like this:

Hi there! I'm a bike messenger by day, aspiring actor by night, and this is my blog. I live in Los Angeles, have a great dog named Jack, and I like piña coladas. (And gettin' caught in the rain.)

...or something like this:

The XYZ Doohickey Company was founded in 1971, and has been providing quality doohickies to the public ever since. Located in Gotham City, XYZ employs over 2,000 people and does all kinds of awesome things for the Gotham community.

As a new WordPress user, you should go to your dashboard to delete this page and create new pages for your content. Have fun!

Sample Page originally appeared on AskApache.com

3 Ways to Serve PDF Files using Htaccess Cookies, Headers, Rewrites

AskApache — Sun, 21 Aug 2011 03:07:53 +0000

AskApache.com

FYI, using the Mod_Rewrite Variables Cheatsheet makes this example, and all advanced .htaccess code easier to understand. This demo lets you set a cookie with 1 of 3 values, then you just request the pdf file with a normal link click and get 1 of 3 different responses. This is accomplished with a nice bit of .htaccess code.

As I explain the htaccess code that achieves this, keep in mind this is merely one simple application for this code. It's much more advanced than your basic htaccess trick, notice how this htaccess acts like a php script, very unusual.. I really wanted to share this trick after I created it for one of my clients because this is the tip of the iceberg. Another use would be to display an alternate style sheet depending on a users theme preference. The coolest thing is that it uses multiple advanced .htaccess ideas. This code uses mod_headers to set the Content-Disposition header for forcing a download and uses mod_rewrite to: Send different Content-Type headers, Check the value of a cookie, Set environment variables for use later by mod_headers header directive

Set PDF Viewing Mode - Make a selection, then click the view pdf button.

Inline Download Save As View PDF using selected mode »

What's Going On

There are 3 different ways for a server to send a pdf file in response to a request for one. This causes 3 different ways to open/view the pdf file in the clients browser.

The browser display's a "Save File As" dialog, allowing you to save the file or open.
The browser opens the pdf file "Inline", opening the pdf file in the browser like a web page.
The browser "Downloads" the pdf file automatically as an "Attachment" and then causes an external pdf reader program like adobe reader to open the file.

Some people prefer to have the option of saving the file to view later, some prefer opening it with an external program, and some just like the pdf file to load right in the browser... The point is that by using .htaccess, we can let them choose any of the 3 methods and save their preference for all further pdf files requested from our site by that user.

How It Works

When you click on one of the 3 demo buttons above, "Inline", "Save As", or "Download", a cookie named askapache_pdf is saved in your browser using the javascript below, with the value being set to which button you clicked. Then when you request the pdf file the .htaccess code below uses mod_rewrite to read the value of the askapache_pdf cookie, and depending on which was your preference it will send alternate HTTP Headers that control how your browser handles the file.

Unique HTTP Headers Returned

When it comes down to it, the following information is the 3 modes. Notice each one is different, because these headers are the only thing controlling how your browser handles the file.

Save As Mode (askapache_pdf=s)

Content-Disposition: attachment
Content-Type: application/pdf

Inline Mode (askapache_pdf=i)

Content-Type: application/pdf

Download Mode (askapache_pdf=a)

Content-Type: application/octet-stream

Htaccess Demo File

For the demo I created the folder /storage/pdf/ and this is the .htaccess file at /storage/pdf/.htaccess

The default Content-Type for .pdf files. This will make .pdf files default Content-Type header have the value 'application/pdf' - but the default can be overridden by using RewriteRule with the [T='different/type']

AddType application/pdf .pdf

Turn on the rewrite engine if its already on you dont need this

RewriteEngine On

Skip RewriteRules if not .pdf request, like autoindexing. The next [2] RewriteRule directives are specific for .pdf files so if the filename requested does not end in .pdf then the [S=2] instructs the next 2 RewriteRule directives to be completely skipped.

RewriteRule !.*\.pdf$ - [S=2]

The first RewriteCond checks to see if the askapache_pdf cookie is NOT set. The second RewriteCond checks to see if the askapche_pdf cookie has the value of s, which is the value corresponding to someone clicking the "Save As" button.

The [NC,OR] flag means that if the cookie askapache_pdf does not exist, OR (next cond) if the askapache_pdf cookie does exist and is set to 's' then process the RewriteRule. If neither cond is true the rewriterule is skipped.

If one of the RewriteCond is true, then the RewriteRule is processed. The RewriteRule applies to any/all requests (.*) but doesn't rewrite anything (-) This RewriteRule sets an Apache environment variable ASKAPACHE_PDFS to have the value of 1 if either rewritecond is true. The variable can be checked by any directives following the rewriterule in the whole htaccess file. The ASKAPACHE_PDFS ends in S because if this variable exists then it means the users preference is 'Save As'

Notice that if the user requested the pdf file without selecting a preference i.e. no cookie exists, then the ASKAPACHE_PDFS variable is still set. This just lets us pick the default preference for them, in this example the default is 'Save As'

RewriteCond %{HTTP_COOKIE} !^.*askapache_pdf.*$ [NC,OR]
RewriteCond %{HTTP_COOKIE} ^.*askapache_pdf=s.*$ [NC]
RewriteRule .* - [E=ASKAPACHE_PDFS:1]

The RewriteCond checks the askapache_pdf cookie for the value 'a' which 'a' represents 'Download'

If the cookies value is 'a' then the RewriteRule overrides the default Content-Type from 'application/pdf' set with AddType earlier, to 'application/octet-stream', which is a special content-type that tells the browser that the file cannot be loaded by the browser 'Inline', but must be saved which will be opened by an external viewer depending on browser configuration and plugins.

RewriteCond %{HTTP_COOKIE} ^.*askapache_pdf=a.*$
RewriteRule .* - [T=application/octet-stream]

This is superfly. If the cookie/users-preference was 'Save As' (s) then the RewriteRule above the last one set the environment variable ASKAPACHE_PDFS to have the value 1. The Header directive here is ONLY processed in that variable ASKAPACHE_PDFS exists. That is what the end 'env=ASKAPACHE_PDFS' does, it is the condition that must be met or the Header directive is skipped. If the ASKAPACHE_PDFS environment variable set by RewriteRule does exist then the header directive adds the header 'Content-Disposition: attachment' to the normal Response Headers. The 'Content-Disposition: attachment' header instructs your browser to present you with the 'Save As' dialog box allowing you to choose whether you want to save or open.

Header set Content-Disposition "attachment" env=ASKAPACHE_PDFS

Javascript used by Demo

The best place for javascript is quirksmode, here is a definitive article on setting, reading, parsing, etc.. COOKIES.

Note, I now prefer using jQuery over my AAJS javascript library. Also, the whole using cookies aspect is just to highlight some advanced htaccess, you can accomplish this much easier without javascript or cookies.

if(!gi('pdfr'))return;
var pdfr=gi('pdfr');
var cval=getCookie('askapache_pdf');
 
if(cval=='i'){pdfr.innerHTML='Currently set to "Inline".';}
else if(cval=='a'){pdfr.innerHTML='Currently set to "Download" mode.';}
else if(cval=='s'){pdfr.innerHTML='Currently set to "Save As" mode.';}
 
addMyEvent(gi('pdfi'),"mousedown",function(){
  setCookie("askapache_pdf", "i", "", "/", "www.askapache.com"); gi('pdfr').innerHTML = 'Changed mode to "Inline".'; return false; });
addMyEvent(gi('pdfa'),"mousedown",function(){
  setCookie("askapache_pdf", "a", "", "/", "www.askapache.com"); gi('pdfr').innerHTML = 'Changed mode to "Download".'; return false; });
addMyEvent(gi('pdfs'),"mousedown",function(){
  setCookie("askapache_pdf", "s", "", "/", "www.askapache.com"); gi('pdfr').innerHTML = 'Changed mode to "Save As".'; return false; });

Alternative Method - No Cookies + PHP

This is what I came up with first for my client, and then while programming the php I noticed.. Hey! I think I can do the same thing using .htaccess, which would save me on cpu/memory/potential security/etc.. but this works great too. Though you will need to hack the code to get it working probably..

Note that the .htaccess rewrite code I used here used FILENAME-i.pdf or FILENAME-s.pdf to pass the preference to the pdf-dl.php script, it also worked for FILENAME.pdf?i=i

pdf-dl.php

Alternate Method .htaccess

Deny direct request to pdf-dl.php file

RewriteCond %{THE_REQUEST} ^.*pdf-dl\.php.*$ [NC]
RewriteRule .* - [F]

Handle PDF files named anything-i.pdf as inline

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ([^/]*)-i\.pdf$  /cgi-bin/pdf-dl.php?i=i&file=%{DOCUMENT_ROOT}/storage/pdf/$1.pdf [L,NC,QSA,S=1]

Handle PDF files without -i.pdf as attachments

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ([^/]*)\.pdf$  /cgi-bin/pdf-dl.php?file=%{DOCUMENT_ROOT}/storage/pdf/$1.pdf [L,NC,QSA]

More Info

The following is more information about the Content-Dispositon header and related subjects for fast readers.

Interesting Reading

Here is the thread of the original draft proposal for the Content-Disposition header.

Content-Disposition Header, Rens Troost - 22 Jun 1993
- Re: Content-Disposition Header, Nathaniel Borenstein
  - Re: Content-Disposition Header, Gabe Beged-Dov
    - Re: Content-Disposition Header, Rens Troost
    - Re: Content-Disposition Header, Gabe Beged-Dov
    - Content-Disposition Header and multipart/alternative, Rens Troost
    - Re: Content-Disposition Header and multipart/alternative, Nathaniel Borenstein
  - Re: Content-Disposition Header, Keith Moore
    - Re: Content-Disposition Header, Nathaniel Borenstein
    - Re: Content-Disposition Header, Ed Levinson (Contractor)
    - Re: Content-Disposition Header, Keith Moore
    - Re: Content-Disposition Header, Rens Troost
    - Re: Content-Disposition Header, Harald Tveit Alvestrand
  - Re: Content-Disposition Header, Steve Dorner
    - Re: Content-Disposition Header, Rens Troost
      - Re: Content-Disposition Header, Keith Moore
  - Re: Content-Disposition Header, Carlyn M. Lowery

Intense Reading

3 Ways to Serve PDF Files using Htaccess Cookies, Headers, Rewrites originally appeared on AskApache.com

Terminal Escape Code Zen

AskApache — Wed, 13 Apr 2011 04:00:27 +0000

AskApache.com

Lightning Strikes Twice!

LOL..

3rd Dimension Broken with Bash!

So 3D... it'll hurt you eyes! lol.. Man I am cracking up here. Ha but seriously those really do look 3D for terminal though.. I am actually really impressed. Sweet. Here is the little function I wrote to output that grey marble.

Just a word to the wise, start learning and going over some of these concepts, especially the code used in functions, I will be back in a followup that details actually using this stu.

This function is one of my favorites because it is so fast and useful. Like when designing a 256color prompt.

aa_256 ()
{
    local o x=`tput op` y=`printf %$((${COLUMNS}-6))s`;
    for i in {0..256};
    do
        o=00$i;
        echo -e ${o:${#o}-3:3} `tputm "setaf $i" "setab $i"`${y// /=}$x;
    done
}

Ya this is actually not very helpful or useful, but there you have it.

tputm ()
{
    local a;
    for a in "$@";
    do
        echo -en "${a}\n";
    done | tput -S
}

Some people call this function the grey bringer of death. Not really.

a256 ()
{
    ( x=`tput op` y=`printf %$((${COLUMNS}-6))slocal `;
    for i in {242..232} 232 232;
    do
        echo -en "`tput setaf $i;tput setab $i`${y}${x}`tput op`";
    done )
}

Fix screen

Helpful Ncurses Programs

Program Name	Description	Example Usage
infotocap	convert a terminfo description into a termcap description
tic	the terminfo entry-description compiler
toe	table of (terminfo) entries	`toe -a\|sort -d`
infocmp	compare or print out terminfo descriptions	`infocmp -a -L -1 -T -x`
capconvert	automated conversion from termcap to terminfo
stty	prints or changes terminal characteristics, such as baud rate.
clear	clears the terminal's screen
capconvert	automated conversion from termcap to terminfo

ALWAYS check out my functions!

This function will print out the terminal, show it's colors, etc.. I have some really nice ones in this article that I use for tmux, screen, and that sort of thing.

c ()
{
    tput clear;
    pm "$TERM: [colors:`tput colors`/`tput pairs`]";
    RC=`tput op` L1=$(L '=' $(( ${COLUMNS} - 25 )));
    for i in `seq ${1:-0} ${2:-16}`;
    do
        o="  $i";
        echo -e " ${o:${#o}-3:3} `tput setaf $i;tput setab $i`${L1}${RC}";
    done
}

Standard Capabilities

X.364 and iBCS2

\033c - RIS - full reset
\0337 - SC - save cursor
\0338 - RC - restore cursor
\033[r - RSR - not an X.364 mnemonic
\033[m - SGR0 - not an X.364 mnemonic
\033[2J - ED2 - clear page

Specified by ISO 2022

\033(0 - ISO DEC G0 - enable DEC graphics for G0
\033(A - ISO UK G0 - enable UK chars for G0
\033(B - ISO US G0 - enable US chars for G0
\033)0 - ISO DEC G1 - enable DEC graphics for G1
\033)A - ISO UK G1 - enable UK chars for G1
\033)B - ISO US G1 - enable US chars for G1

ISO 2022 charset switching:

ISO/IEC 2022:1994
"Character code structure and extension techniques"
ECMA-035
code structure
- =00..=1F C0 set of control characters
- =20..=7F G0 set of 94 or 96 graphic characters
- =80..=9F C1 set of control characters "C1 controls"
- =A0..=FF G1 set of 94 or 96 graphic characters
- ... G2 and G3
registration authority
- ISO/IEC 2375:1985 Procedure for registration of escape sequences
- "ECMA registry"
- ISO-IR registration number
- ftp://dkuug.dk/i18n/iso2375reg.txt
- Internaltional register of coded character sets to be used with escape sequences
- ISO/IEC JTC1/SC2/WG3
ISO-2022 terminals from Siemens
recode iso-2022..utf-8 not yet implemented
CJK charsets

DEC private controls widely supported by emulators

\033= - DECPAM - application keypad mode
\033> - DECPNM - normal keypad mode
\033< - DECANSI - enter ANSI mode
\033[!p - DECSTR - soft reset
\033 F - S7C1T - 7-bit controls

ECMA modes

ISO 2022

2 - AM - keyboard action mode
4 - IRM - insert/replace mode
12 - SRM - send/receive mode
20 - LNM - linefeed mode

DEC modes

1 - CKM - application cursor keys
2 - ANM - set VT52 mode
3 - COLM - 132-column mode
4 - SCLM - smooth scroll
5 - SCNM - reverse video mode
6 - OM - origin mode
7 - AWM - wraparound mode
8 - ARM - auto-repeat mode

ECMA attribute sequences

0 - NORMAL - normal
1 - +BOLD - bold on
2 - +DIM - dim on
3 - +ITALIC - italic on
4 - +UNDERLINE - underline on
5 - +BLINK - blink on
6 - +FASTBLINK - fastblink on
7 - +REVERSE - reverse on
8 - +INVISIBLE - invisible on
9 - +DELETED - deleted on
10 - MAIN-FONT - select primary font
11 - ALT-FONT-1 - select alternate font 1
12 - ALT-FONT-2 - select alternate font 2
13 - ALT-FONT-3 - select alternate font 3
14 - ALT-FONT-4 - select alternate font 4
15 - ALT-FONT-5 - select alternate font 5
16 - ALT-FONT-6 - select alternate font 6
17 - ALT-FONT-7 - select alternate font 7
18 - ALT-FONT-1 - select alternate font 1
19 - ALT-FONT-1 - select alternate font 1
20 - FRAKTUR - Fraktur font
21 - DOUBLEUNDER - double underline
22 - -DIM - dim off
23 - -ITALIC - italic off
24 - -UNDERLINE - underline off
25 - -BLINK - blink off
26 - -FASTBLINK - fastblink off
27 - -REVERSE - reverse off
28 - -INVISIBLE - invisible off
29 - -DELETED - deleted off

Init strings

Name	Description
`is1`	init_1string
`is2`	init_2string
`is3`	init_3string
`rs1`	reset_1string
`rs2`	reset_2string
`rs3`	reset_3string
`smcup`	enter_ca_mode
`rmcup`	exit_ca_mode

Cap strings

Name	Description
so	String of commands to enter standout mode.
se	String of commands to leave standout mode.
sg	Numeric capability, the width on the screen of the magic cookie. This capability is absent in terminals that record appearance modes character by character.
ms	Flag whose presence means that it is safe to move the cursor while the appearance modes are not in the normal state. If this flag is absent, programs should always reset the appearance modes to normal before moving the cursor.
xs	Flag whose presence means that the only way to reset appearance modes already on the screen is to clear to end of line. On a per-character terminal, you must clear the area where the modes are set. On a magic cookie terminal, you must clear an area containing the cookie. See the discussion above.
xt	Flag whose presence means that the cursor cannot be positioned right in front of a magic cookie, and that seis a command to delete the next magic cookie following the cursor. See discussion above.
mb	String of commands to enter blinking mode.
md	String of commands to enter double-bright mode.
mh	String of commands to enter half-bright mode.
mk	String of commands to enter invisible mode.
mp	String of commands to enter protected mode.
mr	String of commands to enter reverse-video mode.
me	String of commands to turn off all appearance modes, including standout mode and underline mode. On some terminals it also turns off alternate character set mode; on others, it may not. This capability must be present if any of mb... mris present.
as	String of commands to turn on alternate character set mode. This mode assigns some or all graphic characters an alternate picture on the screen. There is no standard as to what the alternate pictures look like.
ae	String of commands to turn off alternate character set mode.
sa	String of commands to turn on an arbitrary combination of appearance modes. It accepts 9 parameters, each of which controls a particular kind of appearance mode. A parameter should be 1 to turn its appearance mode on, or zero to turn that mode off. Most terminals do not support the sacapability, even among those that do have various appearance modes. The nine parameters are, in order, `standout` `underline` `reverse` `blink` `half-bright` `double-bright` `blank` `protect` `alt char set`

Variable and Function Index

For stty

BC: tgoto
ospeed: Output Padding
PC: Output Padding
tgetent: Find
tgetflag: Interrogate
tgetnum: Interrogate
tgetstr: Interrogate
tgoto: tgoto
tparam: tparam
tputs: Output Padding
UP: tgoto

Summary of Capability Names

Here are all the terminal capability names in alphabetical order with a brief description of each. For cross references to their definitions, see the index of capability names.

Name	Description
ae	String to turn off alternate character set mode.
al	String to insert a blank line before the cursor.
AL	String to insert `n` blank lines before the cursor.
am	Flag: output to last column wraps cursor to next line.
as	String to turn on alternate character set mode.like.
bc	Very obsolete alternative name for the lecapability.
bl	String to sound the bell.
bs	Obsolete flag: ASCII backspace may be used for leftward motion.
bt	String to move the cursor left to the previous hardware tab stop column.
bw	Flag: leat left margin wraps to end of previous line.
CC	String to change terminal's command character.
cd	String to clear the line the cursor is on, and following lines.
ce	String to clear from the cursor to the end of the line.
ch	String to position the cursor at column `c` in the same line.
cl	String to clear the entire screen and put cursor at upper left corner.
cm	String to position the cursor at line `l`, column `c`.
CM	String to position the cursor at line `l`, column `c`, relative to display memory.
co	Number: width of the screen.
cr	String to move cursor sideways to left margin.
cs	String to set the scroll region.
cS	Alternate form of string to set the scroll region.
ct	String to clear all tab stops.
cv	String to position the cursor at line `l` in the same column.
da	Flag: data scrolled off top of screen may be scrolled back.
db	Flag: data scrolled off bottom of screen may be scrolled back.
dB	Obsolete number: msec of padding needed for the backspace character.
dc	String to delete one character position at the cursor.
dC	Obsolete number: msec of padding needed for the carriage-return character.
DC	String to delete `n` characters starting at the cursor.
dF	Obsolete number: msec of padding needed for the formfeed character.
dl	String to delete the line the cursor is on.
DL	String to delete `n` lines starting with the cursor's line.
dm	String to enter delete mode.
dN	Obsolete number: msec of padding needed for the newline character.
do	String to move the cursor vertically down one line.
DO	String to move cursor vertically down `n` lines.
ds	String to disable the display of the status line.
dT	Obsolete number: msec of padding needed for the tab character.
ec	String of commands to clear `n` characters at cursor.
ed	String to exit delete mode.
ei	String to leave insert mode.
eo	Flag: output of a space can erase an overstrike.
es	Flag: other display commands work while writing the status line.
ff	String to advance to the next page, for a hardcopy terminal.
fs	String to move the cursor back from the status line to its previous position (outside the status line).
gn	Flag: this terminal type is generic, not real.
hc	Flag: hardcopy terminal.
hd	String to move the cursor down half a line.
ho	String to position cursor at upper left corner.
hs	Flag: the terminal has a status line.
hu	String to move the cursor up half a line.
hz	Flag: terminal cannot accept ~as output.
i1	String to initialize the terminal for each login session.
i3	String to initialize the terminal for each login session.
ic	String to insert one character position at the cursor.
IC	String to insert `n` character positions at the cursor.
if	String naming a file of commands to initialize the terminal.
im	String to enter insert mode.
in	Flag: outputting a space is different from moving over empty positions.
ip	String to output following an inserted character in insert mode.
is	String to initialize the terminal for each login session.
it	Number: initial spacing between hardware tab stop columns.
k0	String of input sent by function key 0 or 10.
k1 ... k9	Strings of input sent by function keys 1 through 9.
K1 ... K5	Strings sent by the five other keys in 3-by-3 array with arrows.
ka	String of input sent by the “clear all tabs” key.
kA	String of input sent by the “insert line” key.
kb	String of input sent by the “backspace” key.
kC	String of input sent by the “clear screen” key.
kd	String of input sent by typing the down-arrow key.
kD	String of input sent by the “delete character” key.
ke	String to make the function keys work locally.
kE	String of input sent by the “clear to end of line” key.
kF	String of input sent by the “scroll forward” key.
kh	String of input sent by typing the “home-position” key.
kH	String of input sent by the “home down” key.
kI	String of input sent by the “insert character” or “enter insert mode” key.
kl	String of input sent by typing the left-arrow key.
kL	String of input sent by the “delete line” key.
km	Flag: the terminal has a Meta key.
kM	String of input sent by the “exit insert mode” key.
kn	Numeric value, the number of numbered function keys.
kN	String of input sent by the “next page” key.
ko	Very obsolete string listing the terminal's named function keys.
kP	String of input sent by the “previous page” key.
kr	String of input sent by typing the right-arrow key.
kR	String of input sent by the “scroll reverse” key.
ks	String to make the function keys transmit.
kS	String of input sent by the “clear to end of screen” key.
kt	String of input sent by the “clear tab stop this column” key.
kT	String of input sent by the “set tab stop in this column” key.
ku	String of input sent by typing the up-arrow key.
l0	String on keyboard labelling function key 0 or 10.
l1 ... l9	Strings on keyboard labelling function keys 1 through 9.
le	String to move the cursor left one column.
LE	String to move cursor left `n` columns.
li	Number: height of the screen.
ll	String to position cursor at lower left corner.
lm	Number: lines of display memory.
LP	Flag: writing to last column of last line will not scroll.
mb	String to enter blinking mode.
md	String to enter double-bright mode.
me	String to turn off all appearance modes
mh	String to enter half-bright mode.
mi	Flag: cursor motion in insert mode is safe.
mk	String to enter invisible mode.
mm	String to enable the functioning of the Meta key.
mo	String to disable the functioning of the Meta key.
mp	String to enter protected mode.
mr	String to enter reverse-video mode.
ms	Flag: cursor motion in standout mode is safe.
nc	Obsolete flag: do not use ASCII carriage-return on this terminal.
nd	String to move the cursor right one column.
NF	Flag: do not use XON/XOFF flow control.
nl	Obsolete alternative name for the doand sfcapabilities.
ns	Flag: the terminal does not normally scroll for sequential output.
nw	String to move to start of next line, possibly clearing rest of old line.
os	Flag: terminal can overstrike.
pb	Number: the lowest baud rate at which padding is actually needed.
pc	String containing character for padding.
pf	String to terminate redirection of output to the printer.
po	String to redirect further output to the printer.
pO	String to redirect `n` characters ofoutput to the printer.
ps	String to print the screen on the attached printer.
rc	String to move to last saved cursor position.
RI	String to move cursor right `n` columns.
rp	String to output character `c` repeated `n` times.
rs	String to reset the terminal from any strange modes.
sa	String to turn on an arbitrary combination of appearance modes.
sc	String to save the current cursor position.
se	String to leave standout mode.
sf	String to scroll the screen one line up.
SF	String to scroll the screen `n` lines up.
sg	Number: width of magic standout cookie. Absent if magic cookies are not used.
so	String to enter standout mode.
sr	String to scroll the screen one line down.
SR	String to scroll the screen `n` line down.
st	String to set tab stop at current cursor column on all lines. programs.
ta	String to move the cursor right to the next hardware tab stop column.
te	String to return terminal to settings for sequential output.
ti	String to initialize terminal for random cursor motion.
ts	String to move the terminal cursor into the status line.
uc	String to underline one character and move cursor right.
ue	String to turn off underline mode
ug	Number: width of underlining magic cookie. Absent if underlining doesn't use magic cookies.
ul	Flag: underline by overstriking with an underscore.
up	String to move the cursor vertically up one line.
UP	String to move cursor vertically up `n` lines.
us	String to turn on underline mode
vb	String to make the screen flash.
ve	String to return the cursor to normal.
vi	String to make the cursor invisible.
vs	String to enhance the cursor.
wi	String to set the terminal output screen window.
ws	Number: the width of the status line.
xb	Flag: superbee terminal.
xn	Flag: cursor wraps in a strange way.
xs	Flag: clearing a line is the only way to clear the appearance modes of positions in that line (or, only way to remove magic cookies on that line).
xt	Flag: Teleray 1061; several strange characteristics.

Variable and Function Index

BC: tgoto
ospeed: Output Padding
PC: Output Padding
tgetent: Find
tgetflag: Interrogate
tgetnum: Interrogate
tgetstr: Interrogate
tgoto: tgoto
tparam: tparam
tputs: Output Padding
UP: tgoto

ae: Standout
AL: Insdel Line
al: Insdel Line
am: Wrapping
as: Standout
bc: Cursor Motion
bl: Bell
bs: Cursor Motion
bt: Cursor Motion
bw: Cursor Motion
CC: Basic
cd: Clearing
ce: Clearing
ch: Cursor Motion
cl: Clearing
CM: Cursor Motion
cm: Cursor Motion
co: Screen Size
cr: Cursor Motion
cS: Scrolling
cs: Scrolling
ct: Initialization
cv: Cursor Motion
da: Scrolling
dB: Pad Specs
db: Scrolling
dC: Pad Specs
DC: Insdel Char
dc: Insdel Char
dF: Pad Specs
DL: Insdel Line
dl: Insdel Line
dm: Insdel Char
dN: Pad Specs
DO: Cursor Motion
do: Cursor Motion
ds: Status Line
dT: Pad Specs
ec: Clearing
ed: Insdel Char
ei: Insdel Char
eo: Basic
es: Status Line
ff: Cursor Motion
fs: Status Line
gn: Basic
hc: Basic
hd: Half-Line
ho: Cursor Motion
hs: Status Line
hu: Half-Line
hz: Basic
i1: Initialization
i3: Initialization
IC: Insdel Char
ic: Insdel Char
if: Initialization
im: Insdel Char
in: Insdel Char
ip: Insdel Char
is: Initialization
it: Initialization
K1...K5: Keypad
k1...k9: Keypad
kA...kT: Keypad
ka...ku: Keypad
km: Meta Key
l0...l9: Keypad
LE: Cursor Motion
le: Cursor Motion
li: Screen Size
ll: Cursor Motion
lm: Scrolling
LP: Wrapping
mb: Standout
md: Standout
me: Standout
mh: Standout
mi: Insdel Char
mk: Standout
mm: Meta Key
mo: Meta Key
mp: Standout
mr: Standout
ms: Underlining
ms: Standout
nc: Cursor Motion
nd: Cursor Motion
NF: Initialization
nl: Cursor Motion
ns: Scrolling
nw: Cursor Motion
os: Basic
pb: Pad Specs
pc: Pad Specs
pf: Printer
pO: Printer
po: Printer
ps: Printer
rc: Cursor Motion
RI: Cursor Motion
rp: Basic
rs: Initialization
sa: Standout
sc: Cursor Motion
se: Standout
SF: Scrolling
sf: Scrolling
sg: Standout
so: Standout
SR: Scrolling
sr: Scrolling
st: Initialization
ta: Cursor Motion
te: Initialization
ti: Initialization
ts: Status Line
uc: Underlining
ue: Underlining
ug: Underlining
ul: Underlining
UP: Cursor Motion
up: Cursor Motion
us: Underlining
vb: Bell
ve: Cursor Visibility
vi: Cursor Visibility
vs: Cursor Visibility
wi: Windows
ws: Status Line
xb: Basic
xn: Wrapping
xs: Standout
xt: Standout
xt: Cursor Motion

Basic: Basic characteristics.
Screen Size: Screen size, and what happens when it changes.
Cursor Motion: Various ways to move the cursor.
Wrapping: What happens if you write a character in the last column.
Scrolling: Pushing text up and down on the screen.
Windows: Limiting the part of the window that output affects.
Clearing: Erasing one or many lines.
Insdel Line: Making new blank lines in mid-screen; deleting lines.
Insdel Char: Inserting and deleting characters within a line.
Standout: Highlighting some of the text.
Underlining: Underlining some of the text.
Cursor Visibility: Making the cursor more or less easy to spot.
Bell: Attracts user's attention; not localized on the screen.
Keypad: Recognizing when function keys or arrows are typed.
Meta Key: META acts like an extra shift key.
Initialization: Commands used to initialize or reset the terminal.
Pad Specs: Info for the kernel on how much padding is needed.
Status Line: A status line displays background information.
Half-Line: Moving by half-lines, for superscripts and subscripts.
Printer: Controlling auxiliary printers of display terminals.

Translated Term Capabilities

This is helpful so you can understand what a term cap does, by looking at the long name.

Tput Name	Terminfo Long Name
@7	key_end
AB	set_a_background
AF	set_a_foreground
AL	parm_insert_line
AX	AX
Co	max_colors
DC	parm_dch
DL	parm_delete_line
DO	parm_down_cursor
E0	E0
F1	key_f11
F2	key_f12
G0	G0
HC	5i
IC	parm_ich
Ic	initialize_color
Km	delete_line
LE	parm_left_cursor
NC	no_color_video
ND	MT
NP	NL
RI	parm_right_cursor
S0	S0
UP	parm_up_cursor
YA	NR
YC	YB
YE	YD
YG	YF
ac	acs_chars
ae	exit_alt_charset_mode
al	insert_line
am	auto_right_margin
as	enter_alt_charset_mode
back_color_erase	backspaces_with_bs
bl	bell
bs	eat_newline_glitch
bt	back_tab
bw	auto_left_margin
cb	clr_bol
cc	can_change
cd	clr_eos
ce	clr_eol
cl	clear_screen
cm	cursor_address
co	columns
col_addr_glitch	ceol_standout_glitch
cpi_changes_res	cr_cancels_micro_mode
cr	carriage_return
cs	change_scroll_region
ct	clear_all_tabs
cursor_up	scroll_reverse
da	crt_no_scrolling
db	dest_tabs_magic_smso
dc	delete_character
dl	key_mouse
do	cursor_down
eA	ena_acs
ei	exit_insert_mode
eo	erase_overstrike
es	generic_type
gn	gnu_has_meta_key
hard_copy	hard_cursor
has_meta_key	has_hardware_tabs
has_status_line	has_print_wheel
hl	hc
ho	cursor_home
hs	hue_lightness_saturation
im	enter_insert_mode
in	hz
insert_null_glitch	linefeed_is_newline
is	init_2string
it	init_tabs
k1	key_f1
k2	key_f2
k3	key_f3
k4	key_f4
k5	key_f5
k6	key_f6
k7	key_f7
k8	key_f8
k9	key_f9
k;	key_f10
kB	key_btab
kD	key_dc
kI	key_ic
kN	key_npage
kP	key_ppage
kb	cursor_left
kd	key_down
ke	keypad_local
kh	key_home
kl	key_left
kr	key_right
ks	keypad_xmit
ku	key_up
le	key_backspace
li	lines
mb	enter_blink_mode
md	enter_bold_mode
me	exit_attribute_mode
memory_above	lpi_changes_res
mi	km
move_insert_mode	move_standout_mode
mr	enter_reverse_mode
nc	memory_below
nd	cursor_right
needs_xon_xoff	no_correctly_working_cr
no_pad_char	no_esc_ctlc
non_rev_rmcup	non_dest_scroll_region
nw	newline
nx	ns
op	orig_pair
os	over_strike
pa	max_pairs
prtr_silent	return_does_clr_eol
pt	ms
r2	reset_2string
rc	restore_cursor
row_addr_glitch	semi_auto_right_margin
sa	set_attributes
sc	save_cursor
se	exit_standout_mode
sf	scroll_forward
so	enter_standout_mode
st	set_tab
ta	tab
te	exit_ca_mode
ti	enter_ca_mode
tilde_glitch	status_line_esc_ok
ue	exit_underline_mode
ul	transparent_underline
up	sr
us	enter_underline_mode
vb	flash_screen
ve	cursor_normal
vi	cursor_invisible
vs	cursor_visible
xn	ut
xo	xb
xr	xon_xoff
xt	xs

List of All Terminals

You can view this list with the following command:

$ toe -a|sort -d

VT100 keypad Diagram

VT100 LINK

Here's a diagram of the VT100 keypad keys with their bindings. The top line is the name of the key (some DEC keyboards have the keys labelled somewhat differently, like GOLD instead of PF1, but this is the most "official" name). The second line is the escape sequence it generates in Application Keypad mode (where "$" means the ESC character). The third line contains two items, first the mapping of the key in terminfo, and then in termcap.

   _______________________________________
  |   PF1   |   PF2   |   PF3   |   PF4   |
  |   $OP   |   $OQ   |   $OR   |   $OS   |
  |_kf1__k1_|_kf2__k2_|_kf3__k3_|_kf4__k4_|
  |    7         8         9         -    |
  |   $Ow   |   $Ox   |   $Oy   |   $Om   |
  |_kf9__k9_|_kf10_k;_|_kf0__k0_|_________|
  |    4    |    5    |    6    |    ,    |
  |   $Ot   |   $Ou   |   $Ov   |   $Ol   |
  |_kf5__k5_|_kf6__k6_|_kf7__k7_|_kf8__k8_|
  |    1    |    2    |    3    |         |
  |   $Oq   |   $Or   |   $Os   |  enter  |
  |_ka1__K1_|_kb2__K2_|_ka3__K3_|  $OM    |
  |         0         |   .     |         |
  |        $Op        |  $On    |         |
  |___kc1_______K4____|_kc3__K5_|_kent_@8_|

A better adaptation to modern keyboards such as the PC's, which have a dozen function keys and the keypad 2,4,6,8 keys are labeled with arrows keys, is to use the 5-key arrangement to model the arrow keys as suggested in the terminfo guidelines:

   _______________________________________
  |   PF1   |   PF2   |   PF3   |   PF4   |
  |   $OP   |   $OQ   |   $OR   |   $OS   |
  |_kf1__k1_|_kf2__k2_|_kf3__k3_|_kf4__k4_|
  |    7         8         9         -    |
  |   $Ow   |   $Ox   |   $Oy   |   $Om   |
  |_ka1__K1_|_________|_ka3__K3_|_________|
  |    4    |    5    |    6    |    ,    |
  |   $Ot   |   $Ou   |   $Ov   |   $Ol   |
  |_________|_kb2__K2_|_________|_________|
  |    1    |    2    |    3    |         |
  |   $Oq   |   $Or   |   $Os   |  enter  |
  |_kc1__K4_|_________|_kc3__K5_|  $OM    |
  |         0         |   .     |         |
  |        $Op        |  $On    |         |
  |___________________|_________|_kent_@8_|

SGR parameter values

Name	Description
`0`	default mode (attributes off)
`1`	bold
`2`	dim
`3`	italicized
`4`	underlined
`5`	slow blink
`6`	fast blink
`7`	reverse video
`8`	invisible
`9`	crossed-out (marked for deletion)
`10`	primary font [10 + n (n in 1..9) = nth alternative font]
`20`	Fraktur
`21`	double underline
`22`	turn off 2
`23`	turn off 3
`24`	turn off 4
`25`	turn off 5
`26`	proportional spacing
`27`	turn off 7
`28`	turn off 8
`29`	turn off 9
`30`	black fg
`31`	red fg
`32`	green fg
`33`	yellow fg
`34`	blue fg
`35`	magenta fg
`36`	cyan fg
`37`	white fg
`38`	set fg color as in CCIT T.416
`39`	set default fg color
`40`	black bg
`41`	red bg
`42`	green bg
`43`	yellow bg
`44`	blue bg
`45`	magenta bg
`46`	cyan bg
`47`	white bg
`48`	set bg color as in CCIT T.416
`39`	set default bg color
`50`	turn off 26
`51`	framed
`52`	encircled
`53`	overlined
`54`	turn off 51 & 52
`55`	not overlined
`56-59`	reserved
`61-65`	variable highlights for ideograms.

Sequence     Sequence                             Parameter   or
Mnemonic     Name              Sequence           Value      Mode   terminfo
-----------------------------------------------------------------------------
APC  Applicatn Program Command \E _                -         Delim  -
BEL  Bell *                    ^G                  -         -      bel
BPH  Break Permitted Here *    \E B                -         *      -
BS   Backpace *                ^H                  -         EF     -
CAN  Cancel *                  ^X                  -         -      -   (A)
CBT  Cursor Backward Tab       \E [ Pn Z           1         eF     cbt
CCH  Cancel Previous Character \E T                -         -      -
CHA  Cursor Horizntal Absolute \E [ Pn G           1         eF     hpa (B)
CHT  Cursor Horizontal Tab     \E [ Pn I           1         eF     tab (C)
CMD  Coding Method Delimiter * \E
CNL  Cursor Next Line          \E [ Pn E           1         eF     nel (D)
CPL  Cursor Preceding Line     \E [ Pn F           1         eF     -
CPR  Cursor Position Report    \E [ Pn ; Pn R      1, 1      -      -   (E)
CSI  Control Sequence Intro    \E [                -         Intro  -
CTC  Cursor Tabulation Control \E [ Ps W           0         eF     -   (F)
CUB  Cursor Backward           \E [ Pn D           1         eF     cub
CUD  Cursor Down               \E [ Pn B           1         eF     cud
CUF  Cursor Forward            \E [ Pn C           1         eF     cuf
CUP  Cursor Position           \E [ Pn ; Pn H      1, 1      eF     cup (G)
CUU  Cursor Up                 \E [ Pn A           1         eF     cuu
CVT  Cursor Vertical Tab       \E [ Pn Y           -         eF     -   (H)
DA   Device Attributes         \E [ Pn c           0         -      -
DAQ  Define Area Qualification \E [ Ps o           0         -      -
DCH  Delete Character          \E [ Pn P           1         eF     dch
DCS  Device Control String     \E P                -         Delim  -
DL   Delete Line               \E [ Pn M           1         eF     dl
DLE  Data Link Escape *        ^P                  -         -      -
DMI  Disable Manual Input      \E \                -         Fs     -
DSR  Device Status Report      \E [ Ps n           0         -      -   (I)
DTA  Dimension Text Area *     \E [ Pn ; Pn SPC T  -         PC     -
EA   Erase in Area             \E [ Ps O           0         eF     -   (J)
ECH  Erase Character           \E [ Pn X           1         eF     ech
ED   Erase in Display          \E [ Ps J           0         eF     ed  (J)
EF   Erase in Field            \E [ Ps N           0         eF     -
EL   Erase in Line             \E [ Ps K           0         eF     el  (J)
EM   End of Medium *           ^Y                  -         -      -
EMI  Enable Manual Input       \E b                          Fs     -
ENQ  Enquire                   ^E                  -         -      -
EOT  End Of Transmission       ^D                  -         *      -
EPA  End of Protected Area     \E W                -         -      -   (K)
ESA  End of Selected Area      \E G                -         -      -
ESC  Escape                    ^[                  -         -      -
ETB  End Transmission Block    ^W                  -         -      -
ETX  End of Text               ^C                  -         -      -
FF   Form Feed                 ^L                  -         -      -
FNK  Function Key *            \E [ Pn SPC W       -         -      -
GCC  Graphic Char Combination* \E [ Pn ; Pn SPC B  -         -      -
FNT  Font Selection            \E [ Pn ; Pn SPC D  0, 0      FE     -
GSM  Graphic Size Modify       \E [ Pn ; Pn SPC B  100, 100  FE     -   (L)
GSS  Graphic Size Selection    \E [ Pn SPC C       none      FE     -
HPA  Horz Position Absolute    \E [ Pn `           1         FE     -   (B)
HPB  Char Position Backward    \E [ j              1         FE     -
HPR  Horz Position Relative    \E [ Pn a           1         FE     -   (M)
HT   Horizontal Tab *          ^I                  -         FE     -   (N)
HTJ  Horz Tab w/Justification  \E I                -         FE     -
HTS  Horizontal Tab Set        \E H                -         FE     hts
HVP  Horz & Vertical Position  \E [ Pn ; Pn f      1, 1      FE     -   (G)
ICH  Insert Character          \E [ Pn @           1         eF     ich
IDCS ID Device Control String  \E [ SPC O          -         *      -
IGS  ID Graphic Subrepertoire  \E [ SPC M          -         *      -
IL   Insert Line               \E [ Pn L           1         eF     il
IND  Index                     \E D                -         FE     -
INT  Interrupt                 \E a                -         Fs     -
JFY  Justify                   \E [ Ps SPC F       0         FE     -
IS1  Info Separator #1 *       ^_                  -         *      -
IS2  Info Separator #1 *       ^^                  -         *      -
IS3  Info Separator #1 *       ^]                  -         *      -
IS4  Info Separator #1 *       ^\                  -         *      -
LF   Line Feed                 ^J                  -         -      -
LS1R Locking Shift Right 1 *   \E ~                -         -      -
LS2  Locking Shift 2 *         \E n                -         -      -
LS2R Locking Shift Right 2 *   \E }                -         -      -
LS3  Locking Shift 3 *         \E o                -         -      -
LS3R Locking Shift Right 3 *   \E |                -         -      -
MC   Media Copy                \E [ Ps i           0         -      -   (S)
MW   Message Waiting           \E U                -         -      -
NAK  Negative Acknowledge *    ^U                  -         *      -
NBH  No Break Here *           \E C                -         -      -
NEL  Next Line                 \E E                -         FE     nel (D)
NP   Next Page                 \E [ Pn U           1         eF     -
NUL  Null *                    ^@                  -         -      -
OSC  Operating System Command  \E ]                -         Delim  -
PEC  Pres. Expand/Contract *   \E Pn SPC Z         0         -      -
PFS  Page Format Selection *   \E Pn SPC J         0         -      -
PLD  Partial Line Down         \E K                -         FE     -   (T)
PLU  Partial Line Up           \E L                -         FE     -   (U)
PM   Privacy Message           \E ^                -         Delim  -
PP   Preceding Page            \E [ Pn V           1         eF     -
PPA  Page Position Absolute *  \E [ Pn SPC P       1         FE     -
PPB  Page Position Backward *  \E [ Pn SPC R       1         FE     -
PPR  Page Position Forward *   \E [ Pn SPC Q       1         FE     -
PTX  Parallel Texts *          \E [ \              -         -      -
PU1  Private Use 1             \E Q                -         -      -
PU2  Private Use 2             \E R                -         -      -
QUAD Typographic Quadding      \E [ Ps SPC H       0         FE     -
REP  Repeat Char or Control    \E [ Pn b           1         -      rep
RI   Reverse Index             \E M                -         FE     -   (V)
RIS  Reset to Initial State    \E c                -         Fs     -
RM   Reset Mode *              \E [ Ps l           -         -      -   (W)
SACS Set Add. Char. Sep. *     \E [ Pn SPC /       0         -      -
SAPV Sel. Alt. Present. Var. * \E [ Ps SPC ]       0         -      -   (X)
SCI  Single-Char Introducer    \E Z                -         -      -
SCO  Sel. Char. Orientation *  \E [ Pn ; Pn SPC k  -         -      -
SCS  Set Char. Spacing *       \E [ Pn SPC g       -         -      -
SD   Scroll Down               \E [ Pn T           1         eF     rin
SDS  Start Directed String *   \E [ Pn ]           1         -      -
SEE  Select Editing Extent     \E [ Ps Q           0         -      -   (Y)
SEF  Sheet Eject & Feed *  \E [ Ps ; Ps SPC Y  0,0       -      -
SGR  Select Graphic Rendition  \E [ Ps m           0         FE     sgr (O)
SHS  Select Char. Spacing *    \E [ Ps SPC K       0         -      -
SI   Shift In                  ^O                  -         -      -   (P)
SIMD Sel. Imp. Move Direct. *  \E [ Ps ^           -         -      -
SL   Scroll Left               \E [ Pn SPC @       1         eF     -
SLH  Set Line Home *           \E [ Pn SPC U       -         -      -
SLL  Set Line Limit *          \E [ Pn SPC V       -         -      -
SLS  Set Line Spacing *        \E [ Pn SPC h       -         -      -
SM   Select Mode               \E [ Ps h           none      -      -   (W)
SO   Shift Out                 ^N                  -         -      -   (Q)
SOH  Start Of Heading *        ^A                  -         -      -
SOS  Start of String *         \E X                -         -      -
SPA  Start of Protected Area   \E V                -         -      -   (Z)
SPD  Select Pres. Direction *  \E [ Ps ; Ps SPC S  0,0       -      -
SPH  Set Page Home *           \E [ Ps SPC G       -         -      -
SPI  Spacing Increment         \E [ Pn ; Pn SPC G  none      FE     -
SPL  Set Page Limit *          \E [ Ps SPC j       -         -      -
SPQR Set Pr. Qual. & Rapid. *  \E [ Ps SPC X       0         -      -
SR   Scroll Right              \E [ Pn SPC A       1         eF     -
SRCS Set Reduced Char. Sep. *  \E [ Pn SPC f       0         -      -
SRS  Start Reversed String *   \E [ Ps [           0         -      -
SSA  Start of Selected Area    \E F                -         -      -
SSU  Select Size Unit *        \E [ Pn SPC I       0         -      -
SSW  Set Space Width *         \E [ Pn SPC [       none      -      -
SS2  Single Shift 2 (G2 set)   \E N                -         Intro  -
SS3  Single Shift 3 (G3 set)   \E O                -         Intro  -
ST   String Terminator         \E \                -         Delim  -
STAB Selective Tabulation *    \E [ Pn SPC ^       -         -      -
STS  Set Transmit State        \E S                -         -      -
STX  Start pf Text *           ^B                  -         -      -
SU   Scroll Up                 \E [ Pn S           1         eF     indn
SUB  Substitute *              ^Z                  -         -      -
SVS  Select Line Spacing *     \E [ Pn SPC \       1         -      -
SYN  Synchronous Idle *        ^F                  -         -      -
TAC  Tabul. Aligned Centered * \E [ Pn SPC b       -         -      -
TALE Tabul. Al. Leading Edge * \E [ Pn SPC a       -         -      -
TATE Tabul. Al. Trailing Edge* \E [ Pn SPC `       -         -      -
TBC  Tab Clear                 \E [ Ps g           0         FE     tbc
TCC  Tabul. Centered on Char * \E [ Pn SPC c       -         -      -
TSR  Tabulation Stop Remove  * \E [ Pn SPC d       -         FE     -
TSS  Thin Space Specification  \E [ Pn SC E        none      FE     -
VPA  Vert. Position Absolute   \E [ Pn d           1         FE     vpa
VPB  Line Position Backward *  \E [ Pn k           1         FE     -
VPR  Vert. Position Relative   \E [ Pn e           1         FE     -   (R)
VPR  Vert. Position Relative   \E [ Pn e           1         FE     -   (R)
VT   Vertical Tabulation *     ^K                  -         FE     -
VTS  Vertical Tabulation Set   \E J                -         FE     -

Basic Characteristics

This section documents the capabilities that describe the basic and nature of the terminal, and also those that are relevant to the output of graphic characters.

Name	Description
os	Flag whose presence means that the terminal can overstrike. This means that outputting a graphic character does not erase whatever was present in the same character position before. The terminals that can overstrike include printing terminals, storage tubes (all obsolete nowadays), and many bit-map displays.
eo	Flag whose presence means that outputting a space erases a character position even if the terminal supports overstriking. If this flag is not present and overstriking is supported, output of a space has no effect except to move the cursor. (On terminals that do not support overstriking, you can always assume that outputting a space at a position erases whatever character was previously displayed there.)
gn	Flag whose presence means that this terminal type is a generic type which does not really describe any particular terminal. Generic types are intended for use as the default type assigned when the user connects to the system, with the intention that the user should specify what type he really has. One example of a generic type is the type `network`. Since the generic type cannot say how to do anything interesting with the terminal, termcap-using programs will always find that the terminal is too weak to be supported if the user has failed to specify a real terminal type in place of the generic one. The gnflag directs these programs to use a different error message: “You have not specified your real terminal type”, rather than “Your terminal is not powerful enough to be used”.
hc	Flag whose presence means this is a hardcopy terminal.
rp	String of commands to output a graphic character `c`, repeated `n` times. The first parameter value is the ASCII code for the desired character, and the second parameter is the number of times to repeat the character. Often this command requires padding proportional to the number of times the character is repeated. This effect can be had by using parameter arithmetic with `%`-sequences to compute the amount of padding, then generating the result as a number at the front of the string so that `tputs` will treat it as padding.
hz	Flag whose presence means that the ASCII character cannot be output on this terminal because it is used for display commands. Programs handle this flag by checking all text to be output and replacing each ~with some other character(s). If this is not done, the screen will be thoroughly garbled. The old Hazeltine terminals that required such treatment are probably very rare today, so you might as well not bother to support this flag.
CC	String whose presence means the terminal has a settable command character. The value of the string is the default command character (which is usually ). All the strings of commands in the terminal description should be written to use the default command character. If you are writing an application program that changes the command character, use the CCcapability to figure out how to translate all the display commands to work with the new command character. Most programs have no reason to look at the CCcapability.
xb	Flag whose presence identifies Superbee terminals which are unable to transmit the characters and `Control-C`. Programs which support this flag are supposed to check the input for the code sequences sent by the and keys, and pretend that or `Control-C` (respectively) had been read. But this flag is obsolete, and not worth supporting.

7bit vs. 8bit

These recommendations are optional. IBCS2 allows the leading escape to # be either the 7-bit \E[ or 8-bit \0233 introducer, in accordance with # the ANSI X.364/ISO 6429/ECMA-48 standard.

1.6.1 Describing the Encoding
For example, the cm string for a standard ANSI terminal is written as \E[%i%d;%dH. (\E stands for .) cm by convention always requires two parameters, the vertical and horizontal goal positions, so this string specifies the encoding of two parameters. Here %i increments the two values supplied, and each %d encodes one of the values in decimal. If the cursor position values 20,58 are encoded with this string, the result is \E[21;59H.

First, here are the %-sequences that generate output. Except for %%, each of them encodes one parameter and advances the pointer to the following parameter.

%% Output a single %. This is the only way to represent a literal % in a terminal command with parameters. %% does not use up a parameter.
%d As in printf, output the next parameter in decimal.
%2 Like %02d in printf: output the next parameter in decimal, and always use at least two digits.
%3 Like %03d in printf: output the next parameter in decimal, and always use at least three digits. Note that %4 and so on are _not_ defined.
%. Output the next parameter as a single character whose ASCII code is the parameter value. Like %c in printf.
%+CHAR Add the next parameter to the character CHAR, and output the resulting character. For example, %+ represents 0 as a space, 1 as !, etc.

The following %-sequences specify alteration of the parameters (their values, or their order) rather than encoding a parameter for output. They generate no output; they are used only for their side effects on the parameters. Also, they do not advance the "next parameter" pointer except as explicitly stated. Only %i, %r and %> are defined in standard Unix termcap. The others are GNU extensions.

%i Increment the next two parameters. This is used for terminals that expect cursor positions in origin 1. For example, %i%d,%d would output two parameters with 1 for 0, 2 for 1, etc.
%r Interchange the next two parameters. This is used for terminals whose cursor positioning command expects the horizontal position first.
%s Skip the next parameter. Do not output anything.
%b Back up one parameter. The last parameter used will become once again the next parameter to be output, and the next output command will use it. Using %b more than once, you can back up any number of parameters, and you can refer to each parameter any number of times.
%>C1C2 Conditionally increment the next parameter. Here C1 and C2 are characters which stand for their ASCII codes as numbers. If the next parameter is greater than the ASCII code of C1, the ASCII code of C2 is added to it.
%a OP TYPE POS Perform arithmetic on the next parameter, do not use it up, and do not output anything. Here OP specifies the arithmetic operation, while TYPE and POS together specify the other operand.

Spaces are used above to separate the operands for clarity; the spaces don't appear in the data base, where this sequence is exactly five characters long. The character OP says what kind of arithmetic operation to perform. It can be any of these characters:

= - assign a value to the next parameter, ignoring its old value. The new value comes from the other operand.
+ - add the other operand to the next parameter.
- - subtract the other operand from the next parameter.
* - multiply the next parameter by the other operand.
/ - divide the next parameter by the other operand.

The "other operand" may be another parameter's value or a constant; the character TYPE says which. It can be:

p - Use another parameter. The character POS says which parameter to use. Subtract 64 from its ASCII code to get the position of the desired parameter relative to this one. Thus, the character A as POS means the parameter after the next one; the character ? means the parameter before the next one.
c - Use a constant value. The character POS specifies the value of the constant. The 0200 bit is cleared out, so that 0200 can be used to represent zero.

The following %-sequences are special purpose hacks to compensate for the weird designs of obscure terminals. They modify the next parameter or the next two parameters but do not generate output and do not use up any parameters. %m is a GNU extension; the others are defined in standard Unix termcap.

%n - Exclusive-or the next parameter with 0140, and likewise the parameter after next.
%m - Complement all the bits of the next parameter and the parameter after next.
%B - Encode the next parameter in BCD. It alters the value of the parameter by adding six times the quotient of the parameter by ten. Here is a C statement that shows how the new value is computed: PARM = (PARM / 10) * 16 + PARM % 10;
%D - Transform the next parameter as needed by Delta Data terminals. This involves subtracting twice the remainder of the parameter by 16. PARM -= 2 * (PARM % 16);

Terminal Type Name Conventions

Here is a list of standard suffixes and their conventional meanings:

-w - Short for "wide". This is a mode that gives the terminal more columns than usual. This is normally a user option.
-am - "Automatic margins". This is an alternate description for use when the terminal's margin-wrap switch is on; it contains the am flag. The implication is that normally the switch is off and the usual description for the terminal says that the switch is off.
-nam - "No automatic margins". The opposite of -am, this names an alternative description which lacks the am flag. This implies that the terminal is normally operated with the margin-wrap switch turned on, and the normal description of the terminal says so.
-na - "No arrows". This terminal description initializes the terminal to keep its arrow keys in local mode. This is a user option.
-rv - "Reverse video". This terminal description causes text output for normal video to appear as reverse, and text output for reverse video to come out as normal. Often this description differs from the usual one by interchanging the two strings which turn reverse video on and off.

This is a user option; you can choose either the "reverse video" variant terminal type or the normal terminal type, and termcap will obey.

-s - "Status". Says to enable use of a status line which ordinary output does not touch (*note Status Line::).

Some terminals have a special line that is used only as a status line. For these terminals, there is no need for an -s variant; the status line commands should be defined by default. On other terminals, enabling a status line means removing one screen line from ordinary use and reducing the effective screen height. For these terminals, the user can choose the -s variant type to request use of a status line.

-NLINES - Says to operate with NLINES lines on the screen, for terminals such as the Ambassador which provide this as an option. Normally this is a user option; by choosing the terminal type, you control how many lines termcap will use.
-NPAGESp - Says that the terminal has NPAGES pages worth of screen memory, for terminals where this is a hardware option.
-unk - Says that description is not for direct use, but only for reference in tc capabilities. Such a description is a kind of subroutine, because it describes the common characteristics of several variant descriptions that would use other suffixes in place of -unk.

MS-DOS ANSI.SYS

Here is a description of the color and attribute controls supported in the ANSI.SYS driver under MS-DOS. Most console drivers and ANSI terminal emulators for Intel boxes obey these. They are a proper subset of the ECMA-48 escapes.

Bright black becomes gray, bright brown becomes yellow. These coincide with the prescriptions of the ISO 6429/ECMA-48 standard. * If the 5 attribute is on and you set a background color (40-47) it is supposed to enable bright background.

0        all attributes off
1        foreground bright
4        underscore on
5        blink on/background bright (not reliable with brown)
7        reverse-video
8        set blank (non-display)
10       set primary font
11       set first alternate font (on PCs, display ROM characters 1-31)
12       set second alternate font (on PCs, display IBM high-half chars)
3n       set foreground color       / 0=black, 1=red,     2=green, 3=brown,
4n       set background color       \ 4=blue,  5=magenta, 6=cyan,  7=white

STTY

Stty Control Settings

Name	Description
parenb	`parenb` Generate parity bit in output and expect parity bit in input. May be negated.
parodd	Set odd parity (even if negated). May be negated.
cs5, cs6, cs7, cs8	Set character size to 5, 6, 7, or 8 bits.
hup, hupcl	Send a hangup signal when the last process closes the tty. May be negated.
cstopb	Use two stop bits per character (one if negated). May be negated.
cread	Allow input to be received. May be negated.
clocal	Disable modem control signals. May be negated.
crtscts	Enable RTS/CTS flow control. Disables DTR/DSR flow control. Non-POSIX. May be negated.
cdtrdsr	Enable DTR/DSR flow control. Disables RTS/CTS flow control. Non-POSIX. May be negated. No stty-readable form available. It needs to be supported by device. Usage on device without DTR/DSR support could lead to an error and failure of `stty`.

Stty Input settings

Name	Description
ignbrk	Ignore break characters. May be negated.
brkint	Make breaks cause an interrupt signal. May be negated.
ignpar	Ignore characters with parity errors. May be negated.
parmrk	Mark parity errors (with a 255-0-character sequence). May be negated.
inpck	Enable input parity checking. May be negated.
istrip	Clear high (8th) bit of input characters. May be negated.
inlcr	Translate newline to carriage return. May be negated.
igncr	Ignore carriage return. May be negated.
icrnl	Translate carriage return to newline. May be negated.
iutf8	Assume input characters are UTF-8 encoded. May be negated.
ixon	Enable XON/XOFF flow control (that is, `CTRL-S`/`CTRL-Q`). May be negated.
ixoff, tandem	Enable sending of `stop` character when the system input buffer is almost full, and `start` character when it becomes almost empty again. May be negated.
iuclc	Translate uppercase characters to lowercase. Non-POSIX. May be negated.
ixany	Allow any character to restart output (only the start character if negated). Non-POSIX. May be negated.
imaxbel	Enable beeping and not flushing input buffer if a character arrives when the input buffer is full. Non-POSIX. May be negated.

Stty Output settings

These arguments specify output-related operations.

Name	Description
opost	Postprocess output. May be negated.
olcuc	Translate lowercase characters to uppercase. Non-POSIX. May be negated.
ocrnl	Translate carriage return to newline. Non-POSIX. May be negated.
onlcr	Translate newline to carriage return-newline. Non-POSIX. May be negated.
onocr	Do not print carriage returns in the first column. Non-POSIX. May be negated.
onlret	Newline performs a carriage return. Non-POSIX. May be negated.
ofill	Use fill (padding) characters instead of timing for delays. Non-POSIX. May be negated.
ofdel	Use delete characters for fill instead of null characters. Non-POSIX. May be negated.
nl1, nl0	Newline delay style. Non-POSIX.
cr3, cr2, cr1, cr0	Carriage return delay style. Non-POSIX.
tab3, tab2, tab1, tab0	Horizontal tab delay style. Non-POSIX.
bs1, bs0	Backspace delay style. Non-POSIX.
vt1, vt0	Vertical tab delay style. Non-POSIX.
ff1, ff0	Form feed delay style. Non-POSIX.

Stty Local settings

Name	Description
isig	Enable `interrupt`, `quit`, and `suspend` special characters. May be negated.
icanon	Enable `erase`, `kill`, `werase`, and `rprnt` special characters. May be negated.
iexten	Enable non-POSIX special characters. May be negated.
echo	Echo input characters. May be negated.
echoe, crterase	Echo `erase` characters as backspace-space-backspace. May be negated.
echok	Echo a newline after a `kill` character. May be negated.
echonl	Echo newline even if not echoing other characters. May be negated.
noflsh	Disable flushing after `interrupt` and `quit` special characters. May be negated.
xcase	Enable input and output of uppercase characters by preceding their lowercase equivalents with `\`, when `icanon` is set. Non-POSIX. May be negated.
tostop	Stop background jobs that try to write to the terminal. Non-POSIX. May be negated.
echoprt, prterase	Echo erased characters backward, between `\` and `/`. Non-POSIX. May be negated.
echoctl, ctlecho	Echo control characters in hat notation (`^C`) instead of literally. Non-POSIX. May be negated.
echoke, crtkill	Echo the `kill` special character by erasing each character on the line as indicated by the `echoprt` and `echoe` settings, instead of by the `echoctl` and `echok` settings. Non-POSIX. May be negated.

Stty Combination settings

Name	Description
evenp, parity	Same as `parenb -parodd cs7`. May be negated. If negated, same as `-parenb cs8`.
oddp	Same as `parenb parodd cs7`. May be negated. If negated, same as `-parenb cs8`.
nl	Same as `-icrnl -onlcr`. May be negated. If negated, same as `icrnl -inlcr -igncr onlcr -ocrnl -onlret`.
ek	Reset the `erase` and `kill` special characters to their default values.
sane	Sets all special characters to their default values and: cread -ignbrk brkint -inlcr -igncr icrnl -ixoff -iuclc -ixany imaxbel opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke
cooked	Same as `brkint ignpar istrip icrnl ixon opost isig icanon`, plus sets the `eof` and `eol` characters to their default values if they are the same as the `min` and `time` characters. May be negated. If negated, same as `raw`.
raw	Same as: -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon -ixoff -iuclc -ixany -imaxbel -opost -isig -icanon -xcase min 1 time 0 May be negated. If negated, same as `cooked`.
cbreak	Same as `-icanon`. May be negated. If negated, same as `icanon`.
pass8	Same as `-parenb -istrip cs8`. May be negated. If negated, same as `parenb istrip cs7`.
litout	Same as `-parenb -istrip -opost cs8`. May be negated. If negated, same as `parenb istrip opost cs7`.
decctlq	Same as `-ixany`. Non-POSIX. May be negated.
tabs	Same as `tab0`. Non-POSIX. May be negated. If negated, same as `tab3`.
lcase, LCASE	Same as `xcase iuclc olcuc`. Non-POSIX. May be negated.
crt	Same as `echoe echoctl echoke`.
dec	Same as `echoe echoctl echoke -ixany intr ^C erase ^? kill C-u`.

Special characters

The special characters' default values vary from system to system. They are set with the syntax name value, where the names are listed below and the value can be given either literally, in hat notation (^C), or as an integer which may start with 0x to indicate hexadecimal, 0 to indicate octal, or any other digit to indicate decimal.

For GNU stty, giving a value of ^- or undef disables that special character. (This is incompatible with Ultrix stty, which uses a value of u to disable a special character. GNU stty treats a value u like any other, namely to set that special character to .)

Name	Description
`intr`	Send an interrupt signal.
`quit`	Send a quit signal.
`erase`	Erase the last character typed.
`kill`	Erase the current line.
`eof`	Send an end of file (terminate the input).
`eol`	End the line.
`eol2`	Alternate character to end the line. Non-POSIX.
`swtch`	Switch to a different shell layer. Non-POSIX.
`start`	Restart the output after stopping it.
`stop`	Stop the output.
`susp`	Send a terminal stop signal.
`dsusp`	Send a terminal stop signal after flushing the input. Non-POSIX.
`rprnt`	Redraw the current line. Non-POSIX.
`werase`	Erase the last word typed. Non-POSIX.
`lnext`	Enter the next character typed literally, even if it is a special character. Non-POSIX.

Special settings

min N - Set the minimum number of characters that will satisfy a read until the time value has expired, when -icanon is set.
time N - Set the number of tenths of a second before reads time out if the minimum number of characters have not been read, when -icanon is set.
ispeed N - Set the input speed to N.
ospeed N - Set the output speed to N.
rows N - Tell the tty kernel driver that the terminal has N rows. Non-POSIX.
cols N, columns N - Tell the kernel that the terminal has N columns. Non-POSIX.
size - Print the number of rows and columns that the kernel thinks the terminal has. (Systems that don't support rows and columns in the kernel typically use the environment variables LINES and COLUMNS instead; however, GNU stty does not know anything about them.) Non-POSIX.
line N - Use line discipline N. Non-POSIX.
speed - Print the terminal speed.
N - Set the input and output speeds to N. N can be one of: 0 50 75 110 134 134.5 150 200 300 600 1200 1800 2400 4800 9600 19200 38400 exta extb. exta is the same as 19200; extb is the same as 38400. 0 hangs up the line if -clocal is set.

Color Terminals

color256 ()
{
    local L=$(sed 's/[0-9]//g; s/./#/g' <<<`seq -s+0 $(($COLUMNS - 10))`);
    for i in `seq 0 $(tput colors)`;
    do printf " %.3d `tput setab $i`${L}${R} %.3d `tput setab 0;tput setaf 7`\n" $i $i | tr '#' ' ';
    done
}

for F in `find ~/.terminfo/ -type f | sed 's/^.*\///' | xargs -P0 -I'TT' sh -c 'echo "$(tput -T TT colors): TT"'|sed '/^-/d'| grep ^16:|cut -d: -f2`; do
echo -e "\n\n";
pm $F; export TERM=$F; tput -T $F initc; color256; done

find ~/.terminfo/ -type f | sed 's/^.*\///' | xargs -I'TT' sh -c 'echo "$(tput -T TT colors): TT"'|sed '/^-/d'

Terminals with 16 Colors

aixterm-16color
amiga-vnc
hp2397
hp2397a
hp+color
ibm+16color
konsole-16color
nsterm-16color
nsterm-7-c
nsterm-7-c-s
nsterm-acs-c
nsterm-acs-c-s
nsterm-c
nsterm+c
nsterm-c-7
nsterm-c-acs
nsterm-c-s
nsterm-c-s-7
nsterm-c-s-acs
rxvt-16color
screen-16color
screen-16color-bce
screen-16color-bce-s
screen-16color-s
xterm-16color

Terminals with 52 Colors

d430c-dg-ccc
d430c-unix-25-ccc
d430c-unix-ccc
d430c-unix-s-ccc
d430c-unix-sr-ccc
d430c-unix-w-ccc
d430-dg-ccc
d430-unix-25-ccc
d430-unix-ccc
d430-unix-s-ccc
d430-unix-sr-ccc
d430-unix-w-ccc
dg+ccc
dgunix+ccc

Terminals with 64 Colors

hpterm-color
wy370
wy370-101k
wy370-105k
wy370-EPC
wy370-nk
wy370-rv
wy370-vb
wy370-w
wy370-wvb
wyse370
Eterm-88color
rxvt-88color
xterm-88color
xterm+88color

Terminals with 256 colors

Eterm-256color
gnome-256color
konsole-256color
putty-256color
rxvt-256color
screen-256color
screen-256color-bce
screen-256color-bce-s
screen-256color-s
xterm-256color
xterm+256color

View All tput capabilities

http://blogs.msdn.com/adioltean/articles/271063.aspx

function tputs(){ infocmp -1|sed 's/^[   ]*//; /=/!d; s/=.*//g; /[#\|]/d'; }

Some common terminfo parameter sequences, their termcap equivalents, and some terminal types which commonly have such sequences, are:

terminfo                    termcap   Representative Terminals
---------------------------------------------------------------
%p1%c                       %.        adm
%p1%d                       %d        hp, ANSI standard, vt100
%p1%+%c                 %+x       concept
%i                          %iq       ANSI standard, vt100
%p1%?%>%t%p1%+%;    %>xy      concept
%p2 is printed before %p1   %r        hp

Installing your Own Terminfo

MostLike, or if that is offline I uploaded a copy: mostlike - manpages with color looking like most

rm -rvf ~/.terminfo
mkdir -pv ~/.terminfo
curl -o terminfo.master http://nion.modprobe.de/mostlike.txt; curl -Ss ftp://invisible-island.net/ncurses/terminfo.src.gz
export TERMINFO=~/.terminfo;
sudo tic -e screen-256color,screen-256color-s,screen-256color-bce,screen-256color-bce-s,xterm+256color,xterm,xterm-pcolor terminfo.src

256 Colors in Terminal

256 Colors (Background)

W=`tput setaf 7` RC="\E[0;0;0m" L=$(sed 's/[0-9]//g; s/./ /g' <<<`seq -s+0 $(($COLUMNS/2))`);
 
for i in `seq 0 256`;
do
  printf "${W}\n%.3d `tput setab $i`${L}${RC}" $i;
done

256 Colors (Foreground)

W=`tput setaf 7` WB=`tput setab 0` RC="\E[0;0;0m" L=$(sed 's/[0-9]//g; s/./#/g' <<<`seq -s+0 $(($COLUMNS/2))`);
for i in `seq 0 256`;
do
  printf "${WB}\n%.3d `tput setaf $i`${L}${RC}" $i;
done

Terminal Capabilities - Infocmp

infocmp -1Lq|grep -v "$TERM\|#"|tr -d '  '

DEC/ANSI special sequences

List of the DEC/ANSI special sequences recognized:

----------------------------------------- ----------------------------------------- ----------------------------------------- ----------------------------------------- ----------------------------------------- -----------------------------------------

Action	Meaning
`%%`	The percent sign
`%t`	The time the request was received in Universal Coordinated Time since the epoch (Jan. 1, 1970) measured in microseconds. The value is preceded by `t=`.
`%D`	The time from when the request was received to the time the headers are sent on the wire. This is a measure of the duration of the request. The value is preceded by `D=`. The value is measured in microseconds.
`%{VARNAME}e`	The contents of the environment variable `VARNAME`.
`%{VARNAME}s`	The contents of the SSL environment variable `VARNAME`, if `mod_ssl` is enabled.
`RIS`	full reset
`SC`	save cursor
`RC`	restore cursor
`LL`	home-down
`RSR`	reset scroll region
`DECSTR`	soft reset (VT320)
`S7C1T`	7-bit controls (VT220)
`ISO DEC G0`	enable DEC graphics for G0
`ISO UK G0`	enable UK chars for G0
`ISO US G0`	enable US chars for G0
`ISO DEC G1`	enable DEC graphics for G1
`ISO UK G1`	enable UK chars for G1
`ISO US G1`	enable US chars for G1
`DECPAM`	application keypad mode
`DECPNM`	normal keypad mode
`DECANSI`	enter ANSI mode
`ECMA[+-]AM`	keyboard action mode
`ECMA[+-]IRM`	insert replace mode
`ECMA[+-]SRM`	send receive mode
`ECMA[+-]LNM`	linefeed mode
`DEC[+-]CKM`	application cursor keys
`DEC[+-]ANM`	set VT52 mode
`DEC[+-]COLM`	132-column mode
`DEC[+-]SCLM`	smooth scroll
`DEC[+-]SCNM`	reverse video mode
`DEC[+-]OM`	origin mode
`DEC[+-]AWM`	wraparound mode
`DEC[+-]ARM`	auto-repeat mode

Name	Description
acs_chars	``aaffggiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{\|\|}}~~,
back_tab	`\E[Z,`
bell	`^G,`
carriage_return	`^M,`
change_scroll_region	`\E[%i%p1%d;%p2%dr,`
clear_all_tabs	`\E[3g,`
clear_screen	`\E[H\E[2J,`
clr_bol	`\E[1K,`
clr_eol	`\E[K,`
clr_eos	`\E[J,`
column_address	`\E[%i%p1%dG,`
cursor_address	`\E[%i%p1%d;%p2%dH,`
cursor_down	`^J,`
cursor_home	`\E[H,`
cursor_invisible	`\E[?25l,`
cursor_left	`^H,`
cursor_normal	`\E[?12l\E[?25h,`
cursor_right	`\E[C,`
cursor_up	`\E[A,`
cursor_visible	`\E[?12;25h,`
delete_character	`\E[P,`
delete_line	`\E[M,`
enter_alt_charset_mode	`\E(0,`
enter_am_mode	`\E[?7h,`
enter_blink_mode	`\E[5m,`
enter_bold_mode	`\E[1m,`
enter_ca_mode	`\E[?1049h,`
enter_insert_mode	`\E[4h,`
enter_reverse_mode	`\E[7m,`
enter_secure_mode	`\E[8m,`
enter_standout_mode	`\E[7m,`
enter_underline_mode	`\E[4m,`
erase_chars	`\E[%p1%dX,`
exit_alt_charset_mode	`\E(B,`
exit_am_mode	`\E[?7l,`
exit_attribute_mode	`\E(B\E[m,`
exit_ca_mode	`\E[?1049l,`
exit_insert_mode	`\E[4l,`
exit_standout_mode	`\E[27m,`
exit_underline_mode	`\E[24m,`
flash_screen	`\E[?5h$<100/>\E[?5l,`
init_2string	`\E[\041p\E[?3;4l\E[4l\E>,`
initialize_color	`\E]4;%p1%d;rgb\072%p2%{255}%%{1000}%/%2.2X/%p3%{255}%%{1000}%/%2.2X/%p4%{255}%*%{1000}%/%2.2X\E\,`
insert_line	`\E[L,`
key_b2	`\EOE,`
key_backspace	`\177,`
key_btab	`\E[Z,`
key_dc	`\E[3~,`
key_down	`\EOB,`
key_end	`\EOF,`
key_enter	`\EOM,`
key_f1	`\EOP,`
key_f10	`\E[21~,`
key_f11	`\E[23~,`
key_f12	`\E[24~,`
key_f13	`\EO2P,`
key_f14	`\EO2Q,`
key_f15	`\EO2R,`
key_f16	`\EO2S,`
key_f17	`\E[15;2~,`
key_f18	`\E[17;2~,`
key_f19	`\E[18;2~,`
key_f2	`\EOQ,`
key_f20	`\E[19;2~,`
key_f21	`\E[20;2~,`
key_f22	`\E[21;2~,`
key_f23	`\E[23;2~,`
key_f24	`\E[24;2~,`
key_f25	`\EO5P,`
key_f26	`\EO5Q,`
key_f27	`\EO5R,`
key_f28	`\EO5S,`
key_f29	`\E[15;5~,`
key_f3	`\EOR,`
key_f30	`\E[17;5~,`
key_f31	`\E[18;5~,`
key_f32	`\E[19;5~,`
key_f33	`\E[20;5~,`
key_f34	`\E[21;5~,`
key_f35	`\E[23;5~,`
key_f36	`\E[24;5~,`
key_f37	`\EO6P,`
key_f38	`\EO6Q,`
key_f39	`\EO6R,`
key_f4	`\EOS,`
key_f40	`\EO6S,`
key_f41	`\E[15;6~,`
key_f42	`\E[17;6~,`
key_f43	`\E[18;6~,`
key_f44	`\E[19;6~,`
key_f45	`\E[20;6~,`
key_f46	`\E[21;6~,`
key_f47	`\E[23;6~,`
key_f48	`\E[24;6~,`
key_f49	`\EO3P,`
key_f5	`\E[15~,`
key_f50	`\EO3Q,`
key_f51	`\EO3R,`
key_f52	`\EO3S,`
key_f53	`\E[15;3~,`
key_f54	`\E[17;3~,`
key_f55	`\E[18;3~,`
key_f56	`\E[19;3~,`
key_f57	`\E[20;3~,`
key_f58	`\E[21;3~,`
key_f59	`\E[23;3~,`
key_f6	`\E[17~,`
key_f60	`\E[24;3~,`
key_f61	`\EO4P,`
key_f62	`\EO4Q,`
key_f63	`\EO4R,`
key_f7	`\E[18~,`
key_f8	`\E[19~,`
key_f9	`\E[20~,`
key_home	`\EOH,`
key_ic	`\E[2~,`
key_left	`\EOD,`
key_mouse	`\E[M,`
key_npage	`\E[6~,`
key_ppage	`\E[5~,`
key_right	`\EOC,`
key_sdc	`\E[3;2~,`
key_send	`\E[1;2F,`
key_sf	`\E[1;2B,`
key_shome	`\E[1;2H,`
key_sic	`\E[2;2~,`
key_sleft	`\E[1;2D,`
key_snext	`\E[6;2~,`
key_sprevious	`\E[5;2~,`
key_sr	`\E[1;2A,`
key_sright	`\E[1;2C,`
key_up	`\EOA,`
keypad_local	`\E[?1l\E>,`
\E[?1h\E	`,`
memory_lock	`\El,`
memory_unlock	`\Em,`
orig_pair	`\E[39;49m,`
parm_dch	`\E[%p1%dP,`
parm_delete_line	`\E[%p1%dM,`
parm_down_cursor	`\E[%p1%dB,`
parm_ich	`\E[%p1%d@,`
parm_index	`\E[%p1%dS,`
parm_insert_line	`\E[%p1%dL,`
parm_left_cursor	`\E[%p1%dD,`
parm_right_cursor	`\E[%p1%dC,`
parm_rindex	`\E[%p1%dT,`
parm_up_cursor	`\E[%p1%dA,`
print_screen	`\E[i,`
prtr_off	`\E[4i,`
prtr_on	`\E[5i,`
reset_1string	`\Ec,`
reset_2string	`\E[\041p\E[?3;4l\E[4l\E>,`
restore_cursor	`\E8,`
row_address	`\E[%i%p1%dd,`
save_cursor	`\E7,`
scroll_forward	`^J,`
scroll_reverse	`\EM,`
set_a_background	`\E[%?%p1%{8}%`

Term Sorted

./MKtermsort.sh |sed 's/.*\/\*  \(.*\)  \*\//\1/g'|sort -u|grep ^[a-zA-Z]|sortwc|grep -v ^static|sort -d|tr " " ','|sed 's/\([^,]\{1,\}\),/\1<\/var>,/g'

AB,ac,acs_btee,acsc,acs_chars,acs_hline,acs_llcorner,acs_lrcorner,acs_ltee,acs_plus,acs_rtee,acs_ttee,acs_ulcorner,acs_urcorner,acs_vline,ae,AF,al,AL,alt_scancode_esc,am,apstr,arrow_key_map,as,auto_left_margin,auto_right_margin,back_color_erase,backspace_delay,backspace_if_not_bs,backspaces_with_bs,back_tab,batt1,batt2,bc,bce,bel,bell,bicr,binel,birep,bit_image_carriage_return,bit_image_entwining,bit_image_newline,bit_image_repeat,bit_image_type,bitwin,bitype,bl,blink,bold,box1,box2,box_chars_1,bs,bt,BT,btml,btns,buffer_capacity,bufsz,buttons,bw,bx,can_change,carriage_return,carriage_return_delay,cb,cbt,cc,CC,ccc,cd,ce,ceol_standout_glitch,ch,change_char_pitch,change_line_pitch,change_res_horz,change_res_vert,change_scroll_region,char_padding,char_set_names,chr,chts,ci,civis,cl,clear,clear_all_tabs,clear_margins,clear_screen,clr_bol,clr_eol,clr_eos,cm,CM,cmdch,cnorm,co,Co,code_set_init,col_addr_glitch,colb0,colb1,colb2,colb3,colb4,colb5,colb6,colb7,colf0,colf1,colf2,colf3,colf4,colf5,colf6,colf7,color_names,colornm,colors,cols,column_address,columns,command_character,cpi,cpi_changes_res,cpix,cps,cr,cr_cancels_micro_mode,create_window,crt_no_scrolling,crxm,cs,csin,csnm,csr,ct,cub,cub1,cud,cud1,cuf,cuf1,cup,cursor_address,cursor_down,cursor_home,cursor_invisible,cursor_left,cursor_mem_address,cursor_normal,cursor_right,cursor_to_ll,cursor_up,cursor_visible,cuu,cuu1,cv,cvr,cvvis,CW,cwin,da,daisy,db,dB,dc,dC,DC,dch,dch1,dclk,defbi,defc,define_bit_image_region,define_char,delete_character,delete_line,dest_tabs_magic_smso,device_type,devt,DI,dial,dial_phone,dim,dispc,display_clock,display_pc_char,dis_status_line,DK,dl,DL,dl1,dm,dN,do,DO,docr,dot_horz_spacing,dot_vert_spacing,down_half_line,ds,dsl,dT,dv,eA,eat_newline_glitch,ec,ech,ed,ehhlm,ei,el,el1,elhlm,elohlm,ena_acs,enacs,endbi,end_bit_image_region,enter_alt_charset_mode,enter_am_mode,enter_blink_mode,enter_bold_mode,enter_ca_mode,enter_delete_mode,enter_dim_mode,enter_doublewide_mode,enter_draft_quality,enter_horizontal_hl_mode,enter_insert_mode,enter_italics_mode,enter_left_hl_mode,enter_leftward_mode,enter_low_hl_mode,enter_micro_mode,enter_near_letter_quality,enter_normal_quality,enter_pc_charset_mode,enter_protected_mode,enter_reverse_mode,enter_right_hl_mode,enter_scancode_mode,enter_secure_mode,enter_shadow_mode,enter_standout_mode,enter_subscript_mode,enter_superscript_mode,enter_top_hl_mode,enter_underline_mode,enter_upward_mode,enter_vertical_hl_mode,enter_xon_mode,eo,erase_chars,erase_overstrike,erhlm,es,eslok,ethlm,evhlm,exit_alt_charset_mode,exit_am_mode,exit_attribute_mode,exit_ca_mode,exit_delete_mode,exit_doublewide_mode,exit_insert_mode,exit_italics_mode,exit_leftward_mode,exit_micro_mode,exit_pc_charset_mode,exit_scancode_mode,exit_shadow_mode,exit_standout_mode,exit_subscript_mode,exit_superscript_mode,exit_underline_mode,exit_upward_mode,exit_xon_mode,F1,F2,F3,F4,F5,F6,F7,F8,F9,Fa,FA,Fb,FB,Fc,FC,Fd,FD,Fe,FE,ff,Ff,FF,Fg,FG,fh,Fh,FH,Fi,FI,fixed_pause,Fj,FJ,Fk,FK,Fl,FL,flash,flash_hook,flash_screen,fln,Fm,FM,Fn,FN,Fo,FO,font0,font1,font2,font3,font4,font5,font6,font7,form_feed,Fp,FP,Fq,FQ,Fr,FR,from_status_line,fs,FS,fsl,FT,FU,FV,FW,FX,FY,FZ,G1,G2,G3,G4,GC,GD,generic_type,getm,get_mouse,GH,GL,Gm,gn,gnu_has_meta_key,goto_window,GR,GU,GV,hangup,hard_copy,hard_cursor,has_hardware_tabs,has_meta_key,has_print_wheel,has_status_line,hc,HC,hd,hl,hls,ho,home,hook,horizontal_tab_delay,hpa,hs,ht,hts,hu,HU,hue_lightness_saturation,hup,hz,i1,i2,i3,ic,Ic,IC,ich,ich1,if,il,il1,im,in,ind,indn,init_1string,init_2string,init_3string,initc,init_file,initialize_color,initial ize_pair,initp,init_prog,init_tabs,insert_character,insert_line,insert_null_glitch,insert_padding,invis,ip,iP,Ip,iprog,is,is1,is2,is3,it,k;,k0,k1,K1,k2,K2,k3,K3,k4,K4,k5,K5,k6,k7,k8,k9,ka,kA,ka1,ka3,kact,kb,kB,kb2,kbeg,kBEG,kbs,kbtab,kC,kc1,kc3,kcan,kCAN,kcbt,kclo,kclr,kcmd,kCMD,kcpn,kcpy,kCPY,kcrt,kCRT,kctab,kcub1,kcud1,kcuf1,kcuu1,kd,kD,kDC,kdch1,kDL,kdl1,kdo,ke,kE,ked,kel,kend,kEND,kent,kEOL,kext,kEXT,key_a1,key_a3,key_b2,key_backspace,key_beg,key_btab,key_c1,key_c3,key_cancel,key_catab,key_clear,key_close,key_command,key_copy,key_create,key_ctab,key_dc,key_dl,key_down,key_eic,key_end,key_enter,key_eol,key_eos,key_exit,key_f0,key_f1,key_f10,key_f11,key_f12,key_f13,key_f14,key_f15,key_f16,key_f17,key_f18,key_f19,key_f2,key_f20,key_f21,key_f22,key_f23,key_f24,key_f25,key_f26,key_f27,key_f28,key_f29,key_f3,key_f30,key_f31,key_f32,key_f33,key_f34,key_f35,key_f36,key_f37,key_f38,key_f39,key_f4,key_f40,key_f41,key_f42,key_f43,key_f44,key_f45,key_f46,key_f47,key_f48,key_f49,key_f5,key_f50,key_f51,key_f52,key_f53,key_f54,key_f55,key_f56,key_f57,key_f58,key_f59,key_f6,key_f60,key_f61,key_f62,key_f63,key_f7,key_f8,key_f9,key_find,key_help,key_home,key_ic,key_il,key_left,key_ll,key_mark,key_message,key_mouse,key_move,key_next,key_npage,key_open,key_options,keypad_local,keypad_xmit,key_ppage,key_previous,key_print,key_redo,key_reference,key_refresh,key_replace,key_restart,key_resume,key_right,key_save,key_sbeg,key_scancel,key_scommand,key_scopy,key_screate,key_sdc,key_sdl,key_select,key_send,key_seol,key_sexit,key_sf,key_sfind,key_shelp,key_shome,key_sic,key_sleft,key_smessage,key_smove,key_snext,key_soptions,key_sprevious,key_sprint,key_sr,key_sredo,key_sreplace,key_sright,key_srsume,key_ssave,key_ssuspend,key_stab,key_sundo,key_suspend,key_undo,key_up,kF,kf0,kf1,kf10,kf11,kf12,kf13,kf14,kf15,kf16,kf17,kf18,kf19,kf2,kf20,kf21,kf22,kf23,kf24,kf25,kf26,kf27,kf28,kf29,kf3,kf30,kf31,kf32,kf33,kf34,kf35,kf36,kf37,kf38,kf39,kf4,kf40,kf41,kf42,kf43,kf44,kf45,kf46,kf47,kf48,kf49,kf5,kf50,kf51,kf52,kf53,kf54,kf55,kf56,kf57,kf58,kf59,kf6,kf60,kf61,kf62,kf63,kf7,kf8,kf9,kfnd,kFND,kh,kH,khlp,kHLP,kHOM,khome,khts,kI,kIC,kich1,kil1,kind,kl,kL,kLFT,kll,km,kM,Km,kmous,kmov,kMOV,kmpf1,kmpf2,kmpf3,kmpf4,kmpf5,kmpf6,kmpf7,kmpf8,kmpf9,kmpt1,kmpt2,kmpt3,kmpt4,kmpt5,kmpt6,kmpt7,kmpt8,kmpt9,kmrk,kmsg,kMSG,kn,kN,knl,knp,knpn,knxt,kNXT,ko,kopn,kopt,kOPT,kP,kpp,kppn,kprt,kPRT,kprv,kPRV,kquit,kr,kR,krdo,kRDO,kref,kres,kRES,krfr,kri,kRIT,krmir,krpl,kRPL,krst,ks,kS,ksav,kSAV,kscl,kscr,ksel,ksf1,ksf10,ksf2,ksf3,ksf4,ksf5,ksf6,ksf7,ksf8,ksf9,kslt,kspd,kSPD,kt,kT,ktab,ktbc,ku,kund,kUND,l0,l1,l2,l3,l4,l5,l6,l7,l8,l9,la,label_format,label_height,label_off,label_on,label_width,lab_f0,lab_f1,lab_f10,lab_f2,lab_f3,lab_f4,lab_f5,lab_f6,lab_f7,lab_f8,lab_f9,le,LE,Lf,LF,lf0,lf1,lf10,lf2,lf3,lf4,lf5,lf6,lf7,lf8,lf9,lh,li,linefeed_if_not_lf,linefeed_is_newline,lines,lines_of_memory,ll,lm,LO,lpi,lpi_changes_res,lpix,lvert,lw,ma,maddr,magic_cookie_glitch,magic_cookie_glitch_ul,max_attributes,max_colors,maximum_windows,max_micro_address,max_micro_jump,max_pairs,mb,MC,mc0,mc4,mc5,mc5i,mc5p,mcs,mcub,mcub1,mcud,mcud1,mcuf,mcuf1,mcuu,mcuu1,md,me,meml,memory_above,memory_below,memory_lock,memory_unlock,memu,meta_off,meta_on,mgc,mh,mhpa,mi,Mi,micro_col_size,micro_column_address,micro_down,micro_left,micro_line_size,micro_right,micro_row_address,micro_up,minfo,mir,mjump,mk,ml,ML,mls,mm,mo,mouse_info,move_insert_mode,move_standout_mode,mp,mr,MR,mrcup,ms,msgr,MT,mu,mvpa,MW,nc,NC,ncv,nd,ND,ndscr,needs_xon_xoff,nel,newline,new_line_delay,nl,Nl,NL,nlab,no_color_video,no_correctly_working_cr,no_esc_ctlc,non_dest_scroll_region,non_rev_rmcup,no_pad_char,NP,npc,npins,NR,nrrmc,ns,number_of_function_keys,number_of_pins,num_labels,nw,nx,nxon,oc,op,orc,order_of_pins,orhi,orig_colors,orig_pair,orl,orvi,os,OTbc,OTbs,OTdB,OTdC,OTdN,OTdT,OTG1,OTG2,OTG3,OTG4,OTGC,OTGD,OTGH,OTGL,OTGR,OTGU,OTGV,other_non_function_keys,OTi2,OTkn,OTko,OTma,OTMT,OTnc,OTnl,OTNL,OTns,OTpt,OTrs,OTug,OTxr,output_res_char,output_res_horz_inch,output_res_line,output_res_vert_inch,over_strike,pa,PA,pad,pad_char,padding_baud_rate,pairs,parm_dch,parm_delete_line,parm_down_cursor,parm_down_micro,parm_ich,parm_index,parm_insert_line,parm_left_cursor,parm_left_micro,parm_right_cursor,parm_right_micro,parm_rindex,parm_up_cursor,parm_up_micro,pause,pb,pc,pc_term_options,pctrm,pf,pfkey,pfloc,pfx,pfxl,pk,pkey_key,pkey_local,pkey_plab,pkey_xmit,pl,plab_norm,pln,pn,po,pO,porder,print_rate,print_screen,prot,prtr_non,prtr_off,prtr_on,prtr_silent,ps,pt,PU,pulse,px,QD,qdial,quick_dial,r1,r2,r3,RA,rbim,rc,RC,rcsd,remove_clock,rep,repeat_char,req_for_input,req_mouse_pos,reqmp,reset_1string,reset_2string,reset_3string,reset_file,restore_cursor,return_does_clr_eol,rev,rf,RF,rfi,ri,RI,rin,ritm,rlm,rmacs,rmam,rmclk,rmcup,rmdc,rmicm,rmir,rmkx,rmln,rmm,rmp,rmpch,rmsc,rmso,rmul,rmxon,row_address,row_addr_glitch,rp,rP,RQ,rs,rs1,rs2,rs3,rshm,rsubm,rsupm,rum,rvert,rwidm,RX,s0,s0ds,s1,S1,s1ds,s2,S2,s2ds,s3,S3,s3ds,S4,S5,S6,S7,S8,sa,sA,SA,sam,save_cursor,Sb,sbim,sc,SC,scancode_escape,scesa,scesc,sclk,scp,scroll_forward,scroll_reverse,scs,scsd,sdrfq,se,select_char_set,semi_auto_right_margin,set0_des_seq,set1_des_seq,set2_des_seq,set3_des_seq,set_a_attributes,setab,set_a_background,setaf,set_a_foreground,set_attributes,setb,set_background,set_bottom_margin,set_bottom_margin_parm,set_clock,setcolor,set_color_band,set_color_pair,setf,set_foreground,set_left_margin,set_left_margin_parm,set_lr_margin,set_page_length,set_pglen_inch,set_right_margin,set_right_margin_parm,set_tab,set_tb_margin,set_top_margin,set_top_margin_parm,set_window,sf,Sf,SF,sg,sgr,sgr0,sgr1,sitm,sL,slength,slines,slm,smacs,smam,smcup,smdc,smgb,smgbp,smgl,smglp,smglr,smgr,smgrp,smgt,smgtb,smgtp,smicm,smir,smkx,smln,smm,smpch,smsc,smso,smul,smxon,snlq,snrmq,so,sp,spinh,spinv,sr,SR,sshm,ssubm,ssupm,st,start_bit_image,start_char_set_def,status_line_esc_ok,stop_bit_image,stop_char_set_def,subcs,subscript_characters,sum,supcs,superscript_characters,swidm,SX,ta,tab,tbc,te,termcap_init2,termcap_reset,these_cause_cr,ti,tilde_glitch,TO,tone,topl,to_status_line,transparent_underline,ts,tsl,u0,u1,u2,u3,u4,u5,u6,u7,u8,u9,uc,ue,ug,ul,underline_char,up,UP,up_half_line,us,user0,user1,user2,user3,user4,user5,user6,user7,user8,user9,ut,vb,ve,vi,virtual_terminal,vpa,vs,vt,WA,wait,wait_tone,WG,wi,widcs,wide_char_size,width_status_line,wind,wingo,wnum,ws,wsl,xb,xenl,XF,Xh,xhp,xhpa,xl,Xl,xmc,xn,XN,xo,Xo,xoffc,xoff_character,xon,xonc,xon_character,xon_xoff,xr,Xr,xs,xsb,xt,Xt,Xv,xvpa,Xy,Ya,YA,Yb,YB,Yc,YC,Yd,YD,Ye,YE,Yf,YF,Yg,YG,Yh,Yi,Yj,Yk,Yl,Ym,Yn,Yo,Yp,Yv,Yw,Yx,Yy,Yz,YZ,Za,ZA,Zb,ZB,Zc,ZC,Zd,ZD,Ze,ZE,zerom,zero_motion,Zf,ZF,Zg,ZG,Zh,ZH,Zi,ZI,Zj,ZJ,Zk,ZK,Zl,ZL,Zm,ZM,Zn,ZN,Zo,ZO,Zp,ZP,Zq,ZQ,Zr,ZR,Zs,ZS,Zt,ZT,Zu,ZU,Zv,ZV,Zw,ZW,Zx,ZX,Zy,ZY,Zz,ZZ

TERMINAL TYPE DESCRIPTIONS SOURCE FILE

ANSI, UNIX CONSOLE, AND SPECIAL TYPES
Specials
ANSI.SYS/ISO 6429/ECMA-48 Capabilities
ANSI/ECMA-48 terminals and terminal emulators
DOS ANSI.SYS variants
ANSI console types
BeOS
Linux consoles
Mach
OSF Unix
QNX
NetBSD consoles
FreeBSD console entries
386BSD and BSD/OS Consoles
DEC VT52
DEC VT100 and compatibles
VT100 emulations
X terminal emulators
MGR
UNIX VIRTUAL TERMINALS, VIRTUAL CONSOLES, AND TELNET CLIENTS
Pilot Pro Palm-Top
COMMERCIAL WORKSTATION CONSOLES
Alpha consoles
Sun consoles
Iris consoles
NeWS consoles
NeXT consoles
Sony NEWS workstations
Common Desktop Environment
Non-Unix Consoles
COMMON TERMINAL TYPES
Altos
Hewlett-Packard (hp)
Honeywell-Bull
Lear-Siegler (adm)
Prime
Qume (qvt)
Televideo (tvi)
Visual (vi)
Wyse (wy)
Kermit terminal emulations
NON-ANSI TERMINAL EMULATIONS
Avatar
RBcomm
LCD DISPLAYS
Matrix Orbital
OLDER TERMINAL TYPES
AT&T (att, tty)
Ampex (Dialogue)
Ann Arbor (aa)
Applied Digital Data Systems (adds)
C. Itoh Electronics
Control Data (cdc)
Getronics
Human Designed Systems (Concept)
Contel Business Systems.
Data General (dg)
Datamedia (dm)
Falco

Just something sorta cool for you to check out

{
 local t=`tputm 'clear' 'setaf 75'` l a b f=/tmp/ps IFS=' ';
exec 6<>$f;ps L|tr -s ' ' &>$f;
while read -u6 l;do a=${l/% */} b=${l/* /};
figlet -rtw $((${COLUMNS} /2 )) -f big "$l";
tput sgr0;
command ps wwo pid:6,user:8,vsize:8,comm:20,$a:50 k -$a -A;cont;
done;
};

Terminal Escape Code Zen originally appeared on AskApache.com

Debugging Tools for Windows

AskApache — Thu, 24 Jun 2010 23:43:47 +0000

AskApache.com

I am almost ready to publish the final tutorial on using ssh tunnels from a truecrypt partition on a Windows machine. Of course I choose to go way overboard in my research and the tutorial is full of some pretty awesome windows tricks.. I will come back to this post soon and post all the other advanced tools I use for debugging windows, for now though you MUST know how to debug the kernel and use these basic debugging tools.

WINDOWS NETWORKING !!!!!

Debugging Tools for Windows

Target Computer and Host Computer

Kernel-mode debugging requires a target computer and a host computer. The target computer is used to run the kernel-mode application. The host computer is used to run the debugger. The following diagram shows the typical Microsoft Windows setup that you can use to perform kernel debugging and diagnose system failures. Typical Windows debugging setup This diagram shows the typical setup. However, the current versions of KD and WinDbg (which you installed with this documentation) are flexible. KD and WinDbg can do the following

Debug a target computer that is running Windows.
Debug a target computer that is running on an x86-based platform, an Itanium-based platform, or an x64-based platform.
Can be started from a host computer that is running Windows.
Can be started from a host computer that is on an x86-based platform, an Itanium-based platform, or an x64-based platform.

The target computer and host computer do not have to use the same platform or the same version of Windows. Kernel debugging does not require specific combinations of the free or checked builds. You can debug a free system from a free or checked system, and you can debug a checked system from a free or checked system. However, typically, there is no reason for the host computer to run the slower checked build. Note If you are running the debuggers from an Itanium-based host computer, make sure that you are using the correct version of the binaries. For more information about which version of the debugger package to use, see Choosing a 32-bit or 64-bit Debugger Package.

Debugging Tools for Windows

List of Tools and Documentation

Microsoft Debugging Tools for Windows includes a number of debuggers and other tools. Some of them are described in this documentation, and others are described elsewhere. The following list briefly describes each tool and where its documentation can be found.

Debuggers

Debugging Tools for Windows includes the following debuggers. These are described throughout this documentation, and are referred to by their individual names or collectively as "the debugger":

WinDbg (Windbg.exe): A user-mode and kernel-mode debugger with a graphical interface.
KD (Kd.exe): A kernel-mode debugger with a console interface.
CDB (Cdb.exe): A user-mode debugger with a console interface.
NTSD (Ntsd.exe): A user-mode debugger with a console interface. CDB and NTSD are virtually identical. In this documentation, whenever a reference is made to "CDB", it applies to both CDB and NTSD. When these two debuggers differ, it is noted. (See CDB and NTSD for details.)

Debugging Tools for Windows - Overview

Looking for updates and drivers for your personal computer? You can use Debugging Tools for Windows to debug drivers, applications, and services on systems that are running Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows Server 2008 R2, or Windows 7. You can also use Debugging Tools for Windows to debug the operating system itself. Versions of the Debugging Tools for Windows package are available for 32-bit x86, native Intel Itanium, and native x64 platforms. The latest release of Debugging Tools for Windows is available as part of the Windows Driver Kit (WDK). Note: If you have a system with a 64-bit processor and you are debugging an application on it, you must use one of the native 64-bit packages.

Using Debugging Tools for Windows

	Download Windows Symbol Packages Symbol packages for a variety of Windows versions.
	Install Debugging Tools for Windows 32-bit Version Download page for the latest 32-bit packages.
	Install Debugging Tools for Windows 64-bit Versions Download page for the latest 64-bit packages.
	What's New for Debugging Tools for Windows
	Debugging Tools and Symbols: Getting Started Tips for using Debugging Tools for Windows, with links to presentations and papers on best practices

Debugger How-Tos

	Driver Tip: Debugging Windows Vista
	Improve Driver Debugability
	1394 Kernel Debugging Tips and Tricks [WinHEC 2004; 373 KB]
	Advanced Driver Debugging [336 KB]
	Driver Debugging Basics [WinHEC 2007; 633 KB]
	Debugging Kernel-Mode Driver Framework Drivers
	Debugging User-Mode Driver Framework Drivers Training Sessions
	Debugging Tools for Windows (MSDN)
	HOWTO: Enable Verbose Debug Tracing in Various Drivers and Subsystems (314743)
	WDK Online: Tools for Debugging Drivers

Resources

	WDK Documentation Download
	Driver Developer Community Resources
	Driver Signing Requirements for Windows
	Notes from Windows Development Teams
	Support for Developer Kits and Tools
	Driver Developer Blogs
	Windows Driver Kit (WDK) Version 7.1.0 Release Notes
	WDK Documentation on MSDN

See Also

Microsoft Application Verifier

Additional Tools and Utilities

Debugging Tools for Windows also includes the following tools and utilities:

Logger (Logger.exe and Logexts.dll): A tool and an extension DLL that record the function calls and other actions of a program. Logger is described in this documentation; see Logger and LogViewer.
LogViewer (Logviewer.exe): A tool that displays the logs created by Logger. LogViewer is described in this documentation; see Logger and LogViewer.
ADPlus (Autodump+, Adplus.vbs): A console-based Microsoft Visual Basic script that can automatically create memory dump files and log files with debug output from one or more processes. ADPlus is described in this documentation; see ADPlus.
DbgRpc (Dbgrpc.exe): A tool used to display Microsoft Remote Procedure Call (RPC) state information. DbgRpc is described in this documentation; see RPC Debugging and Using the DbgRpc Tool.
KDbgCtrl (Kernel Debugging Control, Kdbgctrl.exe): A tool that controls and configures the kernel debugging connection. KDbgCtrl is described in this documentation; see Using KDbgCtrl.
SrcSrv (Srcsrv.dll): A source server that can be used to deliver source files while debugging. SrcSrv is described in this documentation; see SrcSrv.
SymSrv (Symsrv.dll): A symbol server that the debugger can use to connect to a symbol store. SymSrv is described in this documentation; see SymSrv.
SymStore (Symstore.exe): A tool used to create a symbol store. SymSrv is described in this documentation; see Using SymStore.
SymProxy: A tool used to create a single HTTP symbol server on your network that all your debuggers can point to. This has the benefit of pointing to multiple symbol servers (both internal and external) with a single symbol path, handling all authentication, and increasing performance via symbol caching. SymProxy is described in this documentation; see SymProxy.
AgeStore (Agestore.exe): A tool that removes old entries in the downstream store of a symbol server or a source server. AgeStore is described in this documentation; see AgeStore.
DBH (Dbh.exe): A tool that displays information about the contents of a symbol file. DBH is described in this documentation; see DBH.
PDBCopy (Pdbcopy.exe): A tool that removes private symbol information from a symbol file, and controls which public symbols are included in the file. PDBCopy is described in this documentation; see PDBCopy.
DumpChk (Dump File Checking Utility, Dumpchk.exe): A tool used to validate a memory dump file. DumpChk is described in this documentation; see DumpChk.
DbgSrv (Dbgsrv.exe): A process server used for remote debugging. DbgSrv is described in this documentation; see Process Servers (User Mode).
KdSrv (Kdsrv.exe): A KD connection server used for remote debugging. KDSrv is described in this documentation; see KD Connection Servers (Kernel Mode).
DbEngPrx (Dbengprx.exe): A repeater (small proxy server) used for remote debugging. DbgSrv is described in this documentation; see Repeaters.


The Remote tool (Remote.exe): A remoting tool that can be used to remotely control any console program, including KD, CDB, and NTSD. The Remote tool is described in this documentation; see Remote Tool and Remote Debugging Through Remote.exe.
GFlags (Global Flags Editor, Gflags.exe): A tool used to control registry keys and other settings. GFlags is described in this documentation; see GFlags.
The Kill tool (Kill.exe): A tool used to terminate a process. The Kill tool is described in this documentation; see Kill Tool.
The Breakin tool (Breakin.exe): A tool used to cause a user-mode break to occur in a process. Breakin.exe is not described in this documentation. Use the breakin /? command for help with this tool.
The List tool (File List Utilit y, List.exe): List.exe is not described in this documentation. Use the list /? command for help with this tool.
TList (Task List Viewer, Tlist.exe): A tool used to list all running processes. TList is described in this documentation; see TList.
RTList (Remote Task List Viewer, Rtlist.exe): A tool used to list running processes via a DbgSrv process server. RTList is not described in this documentation. Use the rtlist /? command for help with this tool.
UMDH (User-Mode Dump Heap utility, Umdh.exe): A tool used to analyze heap allocations. UMDH is described in this documentation; see UMDH.
USBView (Universal Serial Bus Viewer, Usbview.exe): A tool used to display the USB devices connected to a computer. USBView is described in this documentation; see USBView.

If you peform a custom install of Debugging Tools for Windows and select the SDK feature and all of its subfeatures, the libraries, headers, and samples used to build debugger extensions will be installed.

Documentation

"Debugging Tools for Windows" (Debugger.chm): This is the documentation you are currently reading. It is the central documentation for Debugging Tools for Windows.
"Debug Help Library" (Dbghelp.chm): This documentation describes the DbgHelp API and the ImageHlp API, and also explains how to create your own symbol server. This is installed when you peform a custom install of Debugging Tools for Windows and select the SDK feature and its subfeatures.

Tools Outside the Debugging Tools for Windows Package

The following related tools are not part of the Debugging Tools for Windows package:

Dr. Watson (Drwtsn32.exe): A tool used for automatically creating dump files and sending error reports to Microsoft Online Crash Analysis (OCA). Dr. Watson is partially described in this documentation; see Dr. Watson. The other features of Dr. Watson are described in the help file associated with drwtsn32.exe.
Build utility (Build.exe): A compiler and linker used to build debugger extensions and other programs. The Build utility and its documentation can be found in the Windows Driver Kit, and in earlier versions of the Windows DDK.
BinPlace (Binplace.exe): A tool used to control symbol files for build products. BinPlace and its documentation can be found in the Windows Driver Kit, and in earlier versions of the Windows DDK.
Application Verifier (AppVerif.exe and !avrf): A tool used to test user-mode applications. This tool consists of two components: the AppVerif.exe utility and the !avrf extension command. All the features of Application Verifier that are debugger-related are described in Application Verifier. The other features of Application Verifier are described in the help file associated with AppVerif.exe.

Debugging Tools for Windows

WinDbg

Microsoft Windows Debugger (WinDbg) is a powerful Windows-based debugging tool. It is capable of both user-mode and kernel-mode debugging. WinDbg provides full source-level debugging for the Windows kernel, kernel-mode drivers, and system services, as well as user-mode applications and drivers. WinDbg uses the Microsoft Visual Studio debug symbol formats for source-level debugging. It can access any symbol or variable from a module that has PDB symbol files, and can access any public function's name that is exposed by modules that were compiled with COFF symbol files (such as Windows .dbg files). WinDbg can view source code, set breakpoints, view variables (including C++ objects), stack traces, and memory. Its Debugger Command window allows the user to issue a wide variety of commands. For kernel-mode debugging, WinDbg requires two machines (the host computer and the target computer). Kernel debugging is only supported on NT-based Windows operating systems. WinDbg also supports various remote debugging options for both user-mode and kernel-mode targets. WinDbg is the graphical-interface counterpart to CDB / NTSD and to KD.

Debugging Tools for Windows

Microsoft Kernel Debugger (KD) is a character-based console program that enables in-depth analysis of kernel-mode activity on all NT-based operating systems. KD can be used to debug kernel-mode programs and drivers, or to monitor the behavior of the operating system itself. KD also supports multiprocessor debugging. Typically, the KD tool will not be run on the computer being debugged. Two machines (the host computer and the target computer) are needed for kernel-mode debugging. Most KD commands cannot be targeted to specific processes or threads, as they can in CDB, NTSD, and WinDbg.

Debugging different target platforms

KD is capable of debugging a target computer which is running on an x86, Itanium, or x64 platform. The debugger will automatically detect the platform on which the target is running. You do not need to specify the target on the KD command line. The older syntax (using the name I386KD or IA64KD) is obsolete.

Debugging Tools for Windows

CDB and NTSD

CDB and NTSD are console applications which can debug user-mode programs. These two debuggers are nearly identical, except in the manner in which they are launched. This documentation will use "CDB" when referring to the capabilities of both CDB and NTSD. Except as noted, all references to CDB in this documentation apply equally to NTSD. There are a few techniques that can only work properly with CDB, or can only work properly with NTSD. These differences are documented in the appropriate sections.

CDB

Microsoft Console Debugger (CDB) is a character-based console program that enables low-level analysis of Windows user-mode memory and constructs. CDB is extremely powerful for debugging a program that is currently running or has recently crashed ("live analysis"), yet simple to set up. It can be used to investigate the behavior of a working application. In the case of a failing application, CDB can be used to obtain a stack trace or to look at the guilty parameters. It works well across a network (using a remote access server), as it is character-based. With CDB, you can display and execute program code, set breakpoints, and examine and change values in memory. CDB can analyze binary code by "disassembling" it and displaying assembly instructions. It can also analyze source code directly. Because CDB can access memory locations through addresses or global symbols, you can refer to data and instructions by name rather than by address, making it easy to locate and debug specific sections of code. You can also display disassembled machine code. CDB supports debugging multiple threads and processes. It is extensible, and can read and write both paged and non-paged memory. If the target application is itself a console application, the target will share the console window with CDB. To spawn a separate console window for a target console application, use the -2 command-line option.

NTSD

There is a variation of the CDB debugger named Microsoft NT Symbolic Debugger (NTSD). It is identical to CDB in every way, except that it spawns a new text window when it is started, whereas CDB inherits the Command Prompt window from which it was invoked. Like CDB, NTSD is fully capable of debugging both console applications and graphical Windows programs. (The name "Console Debugger" is used to indicate the fact that CDB is classified as a console application; it does not imply that the target application must be a console application.) Since the start command can also be used to spawn a new console window, the following two constructions will give the same results: start cdb parameters ntsd parameters

NTSD in the System32 Directory

Whereas CDB is only available as part of the Debugging Tools for Windows package, NTSD is available both in this package and as part of the Windows system itself. It can be found in the system32 directory of Windows. If you are planning on using the NTSD that appears in the system32 directory, there are two important facts you should be aware of:

This version of NTSD cannot be used for Remote Debugging Through the Debugger.
This version of NTSD may not match the version of the documentation you are currently reading.

To avoid these issues, it is recommended that you use only the version of NTSD or CDB that was installed as part of the Debugging Tools for Windows package.

Controlling CDB or NTSD from the Kernel Debugger

It is possible to redirect the input and output from CDB or NTSD so that it can be controlled from a kernel debugger (either KD or WinDbg). If this technique is used with CDB, the CDB window will appear but will not be useable for input and output. If this is used with NTSD, no console window will appear at all. Controlling NTSD from the kernel debugger is therefore especially useful, since it results in an extremely light-weight debugger that places almost no burden on the computer containing the target application. This combination can be used to debug system processes, shutdown, and the later stages of boot up. See Controlling the User-Mode Debugger from the Kernel Debugger for details.

Debugging Tools for Windows originally appeared on AskApache.com

30x Faster Cache and Site Speed with TMPFS

AskApache — Thu, 18 Mar 2010 15:43:21 +0000

AskApache.com

I haven't had time to post much the past year, so I wanted to make up for that by publishing an article on a topic that would blow your mind and be something that you could actually start using and really get some benefit out of it. This is one of those articles that the majority of web hosting companies would love to see in paperback, so they could burn it. Now ask yourself, if a webhost makes money based on how much memory, bandwidth, and data used by a customer, what would they not want their customers to do? That's right, they do not want their customers to learn how to minimize and drastically reduce these moneymakers. They get giddy when you complain about slow-site-speed, or that it takes a long time for your site to load, because they have exactly the right answer- upgrade your memory, bandwidth, and data by purchasing a more expensive plan.

WARNING!! This article has some seriously advanced stuff in it, pretty far beyond my skill level as well (getting there). I personally shutdown some of my own servers with various webhosts because of this.. Note I said personally, not intentionally. Even after spending almost a year (this has been in my drafts folder a long time) using TMPFS on as many machines as I can, I still make mistakes (gotta pay attention!) and lose a tmpfs folder.. Oh and if you go experimenting with this stuff on your web host, you will almost definately, most certainly be on the road to getting your account terminated if you are with one of the cheap hosts. They hate this stuff because it cuts right into the heart of their profit curves and can seriously disrupt a poorly configured machine. DO NOT TRY THIS!! (except and of course on your own development machines). Of course the whole point of this article is how you can take advantage of this incredible filesystem to get crazy speed improvements.. Those are the follow up articles ;)

For those of you who thought modifying your server httpd.conf and htaccess files is very dangerous, you are right. But this is not like that, this is dangerous in the sense that if you try to rush through with your super amazing "copy and paste skills" (script kids) you will easily lose entire folders. That's because TMPFS is stored in RAM/Memory, and upon reboot RAM is cleared. I personally loathe disclaimers, and if you look around you will see there aren't many even with all my sloppy poorly documented articles... So be careful if you feel up to going further.

Introducing tmpfs

If I had to explain tmpfs in one breath, I'd say that tmpfs is like a ramdisk, but different. Like a ramdisk, tmpfs can use your RAM, but it can also use your swap devices for storage. And while a traditional ramdisk is a block device and requires a mkfs command of some kind before you can actually use it, tmpfs is a filesystem, not a block device; you just mount it, and it's there. All in all, this makes tmpfs the niftiest RAM-based filesystem I've had the opportunity to meet.

Beware of WebHosts

What is a modern day web hosting company? What costs do they actually have? A webhost's only unique ability is their connection to the Internet. That is why you can see such tremendous link speed. Other than that they consist of servers that are getting smaller and cheaper for them every month. The servers they use are generally just like any computer, except much larger and built specifically for multi-tasking.

Virtualization allows you to run multiple applications and operating systems independently on a single server. Additionally, administrators can quickly move workloads from one virtual workspace to another — easily prioritizing business needs while maximizing server resources....

Virtualization removes the limitations of the traditional IT approach, enabling a single PowerEdge server to operate multiple applications simultaneously in "virtual machines"

Hosting Company Tricks

Web hosts like to vaguely describe their products as if you are buying your own powerful machine, but in reality you get placed on the same machine as hundreds or thousands of other customers, and the server basically creates an operating system for each customer using virtualization technology. Everyone on the machine literally is sharing the same RAM and resources, many times even sharing IP address's, and the virtualization software lets them limit the amount of memory / cpu / disk / and bandwidth for each of these virtual machines. That is why so often when a web host has an outage they make big public announcements and it appears that hundreds or thousands of their customers have been affected.. One of their server farm machines goes offline and it literally takes down all the customers virtualized machines with it.

Why it gets Evil

Don't get me wrong, I absolutely love this technology, both the hardware virtualization and the software side, but what I truly do not appreciate is how these companies take advantage of their customers every day and know it. Here's what they do, they make justifications about why one plan costs more than another, and these justifications are always about the same thing: CPU's, how fast the data can crunch.. RAM/Memory: How fast and how much your server can handle in terms of traffic... Disk Usage: How much storage you have... And finally bandwidth: How fast can people get data off your sites, and how many people can connect.

Now lets think for a second. The webhost has a BIG computer/server/machine that has MASSIVE amounts of RAM, DISK, PROCESSING power, and NETWORK bandwidth.. but just like anything they all have limits. So if this machine has 10GB of RAM, and the webhost offered plans that have 1GB of RAM, then on that machine they can only have 10 customers right? WRONG. If each customer pays $100/month, then of course they would love to have as many customers on that machine as possible. This builtin incentive is just the reality and isn't anyone fault.

Where it gets Evil

Here's what goes on.. all the host advertises is the 1GB of guaranteed RAM with your machine, but for even if the web server was fairly busy it would never use all of that ram because all the software is careful not to use too much, or has no need for any RAM. Runtime libraries and internal caches use ram, but it's not directly accessed by the customer, only the software. What happens is when those 10 customers aren't using 100% of their ram, which never happens, then the virtualization technology can use that RAM elsewhere. So technically you do have 1GB of RAM available, but if you aren't using it then it is essentially FREE RAM that they can sell to another customer. The only way this wouldn't work of course is if all 11 customers somehow used 100% of RAM simultaneously, at that point the 11th customer would be ramless. But that is impossible because the system is a load-balancing system that provides both an upper and a lower limit to how much RAM is allotted to each virtual machine.

It sounds unrealistic but I see server farms all the time that are stuffed full of virtual machines, like situations where there are 100 1GB customers all sharing 10GB of RAM.. no-one uses the whole 1GB allotted to them as the maximum amount they can use, and they don't know because it appears they have a lot of free RAM, but really that is virtual RAM and could be used by anyone else on the machine.

Where it gets Fun (for me)

This is actually even worse for anyone who is using what they call "shared-hosting" which is the budget hosting that is the most common. With shared-hosting there is actually some skill involved on the hosting companies part, like real linux skills. In this setup they may or more often may not use any virtualization software. It's just a vanilla multi-user server machine where each customer gets a restricted unix account that powers their website using the same system as thousands of others on the box. This is usually dirt cheap because it costs so little to do, but alot of companies charge outrageous amounts for shared-hosting because they make it look really full-featured, which it can be, they just don't mention 1000 other people use the same machine, hard-drive, /tmp directory, network device, IP address, etc.. Alot of the times the cheaper end of the spectrum is where the most gifted system administrators are located, they are so good with linux administration that they could fit 10 customers and 100 websites on an XBOX converted to run linux, and you'd think you got a great deal until you found out! lol. Anyone alive is able to buy more hardware to expand their capacity to take on more customers, but it takes a lot of knowhow and real skill to have that many users on 1 machine. I've seen pretty extreme cases that are analogous to the XBOX example (which is possible by the way).

I personally love shared-hosting environments, because for those of us who know almost as much or more than the system administrators running the machine we are able to use a disproportionate (legally) amount of the CPU and RAM available on the system. So for example my sites would all show up fast and be able to handle more traffic than several other customers combined. Not because anything has been circumvented, but because I am able to access and utilize as much of the guaranteed 1GB of RAM that I am paying for every month, which is usually just a few bucks. The downside is that when you have corporate sites or really high-traffic sites then you are forced to move to a more powerful machine..

This leads to a familiar situation for some of you.. When your site starts becoming popular and you are getting a lot of traffic, this means that your site could be using 10x the amount of RAM and Bandwidth of any other customer in that server farm. And what that really means to the webhost is that you are costing them 10x what anyone else is.. And if they removed you, they would have the space for 10 new customers to take your place, and they would make 10x more money. DreamHost is notorious for terminating accounts because of that.. It happened to me except I was given the option to pay 5x more a month for their "upgrade" to a VPS. Giant shared-hosts advertise like crazy how they offer unlimited bandwidth, but when you start using 100x more bandwidth than anyone on your server you are costing them 100x what you are paying them, every month. That's why you will never see a webhost offering this kind of unlimited bandwidth that doesn't require you to sign a contract giving them permission to terminate your account for any reason. Seriously read the fine print at DreamHost or anywhere else, it's included because that is a core part of their business to terminate anyone using too much bandwidth since that is bandwidth they can't sell to dozens of other customers. That's why I eventually closed my account with them and moved to a legitimate company, it's a great host for spammers though.

Back in the mid-90's I was doing a lot of war-dialing with my modem and discovering all sorts of networks and machines, many of them were Unix and Solaris based public systems, and when I managed to gain access to the system and found myself staring at a unix shell I was very excited but also a total idiot. In those days of using the phone networks to research unknown systems it was very difficult for anyone to actually get the phone company to trace a call, so instead of what happens today where it is child's play to trace an IP address, back then it was a very real back-and-forth battle between the system admin and whoever was gaining access to their system. Essentially, I would gain a shell or some kind of terminal, and just go at it trying to figure out what it could do, trying all kinds of commands. Inevitably this would eventually alert even the laziest admin and they would proceed to attempt to lock me out. It was great sport and extremely addictive. When my favorite system (a massive sun machine in the basement of a big library) finally locked me out and I couldn't get back in I went to my local library and got some reading material -- one of my favorites was the red hat bible. I was able to acquire my own computer and the first thing I did was install red hat linux onto it from the discs included with the book. For the next several years I was essentially offline, all we had at home was a modem and it was becoming difficult to locate any more systems in my area code.. I was into phreaking of course as well, but I never was able to make free long-distance war-dialing a reality. So I just read the books and learned what I could. I would also goto the library when I could in order to use their machines which were connected to the internet (before aol it was much different than today's internet) and since my time was short I would download as many documents as I could so that I could read them offline. The TLDP documentation that we know today was around back then in various forms, and I read every HOWTO in the index, though not understanding half. The other big resource I found for really intense reading was the kernel documentation, which admitedly I still don't comprehend 1/4th of.. I try and peruse all the new documents when a new kernel is released, since the kernel is where all the real action is, hence the military authoritative name, and that is how I discovered one of the coolest features of Linux that I have found. TMPFS!

TMPFS kills the RAMDISK

Ok so we all know what RAM is, it's the memory cards that most people never see that is used by the computer to store and access data that all programs need. RAM is very expensive compared to most PC components, because it's what makes a computer blazing fast or slow. So real quick lets look at a few (there are not many) ways that various linux hackers use RAM in non-conventional ways in the past.

Tmpfs is a file system which keeps all files in virtual memory. Everything is temporary in the sense that no files will be created on your hard drive. If you reboot, everything in tmpfs will be lost.

In contrast to RAM disks, which get allocated a fixed amount of physical RAM, tmpfs grows and shrinks to accommodate the files it contains and is able to swap unneeded pages out to swap space.

Like a ramdisk, tmpfs can use your RAM, but it can also use your swap devices for storage. And while a traditional ramdisk is a block device and requires a mkfs command of some kind before you can actually use it, tmpfs is a filesystem, not a block device; you just mount it, and it's there. All in all, this makes tmpfs the niftiest RAM-based filesystem I've had the opportunity to meet.

What kind of filesystem is used on your server to store all your site files? EXT4, REISERFS, EXT3, NFS, etc.. are the usual filesystems, Windows users are limited to the NTFS filesystem. A filesystem is different than a device, a device is a hard-drive disk. A filesystem is how the device is formatted to allow for file and folder structures. A hard drive is slow compared to RAM, no question about that. So what if instead of your server serving files off a hard-drive it served files stored in RAM? 30x faster thats what happens!

I just figured out how to store my cached static files created by WP-Super Cache in my server's RAM, and the difference is unbelievable. My "AskApache Crazy Cache" plugin basically forces WP-Super Cache, Hyper Cache, etc.. to recreate a static cached file for every page on a blog. For the AskApache.com site this takes around 3 minutes to complete. Once I switched to using this new method of storing the files on RAM I am able to re-cache the entire site in about 15 seconds!!!!

tmpfs is a dynamically expandable/shrinkable ramdisk, and will # use almost no memory if not populated with files

Tmpfs is a file system which keeps all files in virtual memory.

Everything in tmpfs is temporary in the sense that no files will be created on your hard drive. If you unmount a tmpfs instance, everything stored therein is lost.

tmpfs puts everything into the kernel internal caches and grows and shrinks to accommodate the files it contains and is able to swap unneeded pages out to swap space. It has maximum size limits which can be adjusted on the fly via 'mount -o remount ...'

If you compare it to ramfs (which was the template to create tmpfs) you gain swapping and limit checking. Another similar thing is the RAM disk (/dev/ram*), which simulates a fixed size hard disk in physical RAM, where you have to create an ordinary filesystem on top. Ramdisks cannot swap and you do not have the possibility to resize them.

Since tmpfs lives completely in the page cache and on swap, all tmpfs pages currently in memory will show up as cached. It will not show up as shared or something like that. Further on you can check the actual RAM+swap use of a tmpfs instance with df(1) and du(1).

Both tmpfs and ramfs mount will give you the power of fast reading and writing files from and to the primary memory. When you test this on a small file, you may not see a huge difference. You’ll notice the difference only when you write large amount of data to a file with some other processing overhead such as network.

TMPFS uses RAM+SWAP

TMPFS is another filesystem with uniquely cool capabilities. It stores any files contained within it on RAM and in SWAP which means your server can access any files stored on TMPFS without even having to access the disk, which according to technical stats is around 30 times faster than accessing a file off disk.

Some other cool aspects of TMPFS are that it intelligently and automatically sizes itself to be just alittle bigger then it needs to be. So when you remove files to a folder stored on a TMPFS filesystem, the TMPFS filesystem shrinks by allocating less RAM and/or SWAP. Conversely when adding files to TMPFS it grows larger. You can set the max-size and max-number-of-files as a mount option to make sure your TMPFS never uses all of the available RAM and SWAP, which would halt your server.

Swap

Find the swap size.

# free -m -t
             total       used       free     shared    buffers     cached
Mem:           458         93        364          0          0          0
-/+ buffers/cache:         93        364
Swap:          900          0        900
Total:        1358         93       1264

Adding 3004144k swap on /dev/sdb2.  Priority:-1 extents:1 across:3004144k
Adding 2096472k swap on /dev/sda3.  Priority:-2 extents:1 across:2096472k

Using TMPFS for Cache

The method here will show how to create and use a TMPFS filesystem to hold all the static files created by WP-Super Cache. These static files are served to visitors instead of loading php for every request, so by moving those static files to TMPFS your server will be able to access and start sending your site to the browser 30x faster!

The WP-Super Cache plugin stores all the static files in the wp-content/cache folder of your WordPress installation, so to enable TMPFS we simply will create a new TMPFS filesystem and mount it to the wp-content/cache folder. That makes anything in that folder (all the static files) be part of the TMPFS filesystem.

Boosting Cache with TMPFS

There are a lot of maybe new concepts surrounding TMPFS and it may seem too complicated, but the process of actually setting up a robust tmpfs to use for wp-super-cache's cache folder is actually very simple. As long as you have shell access to your server and the permissions required (any sudo or private server should be good to go) you can set this up in a couple minutes and not really have to give it a second thought or debug anything. Here's the process I've used on several client sites.

Create a TMPFS Filesystem and Mount at /wp-content/cache/
Restore TMPFS Cached Files across Reboots
Keep a semi-current mirror of the TMPFS files on Disk

Create TMPFS at wp-content/cache

/etc/fstab

tmpfs /home/askapache/wp-content/cache tmpfs defaults,size=2g,noexec,nosuid,uid=648,gid=648,mode=1755 0 0

Restoring TMPFS across Reboots

In /etc/rc.local

ionice -c3 -n7 nice -n 19 rsync -ahv --stats --delete /_b/tmpfs/cache/ /home/askapache/wp-content/cache/ 1>/dev/null

Mirroring TMPFS to Disk

Cronjob entry

*/5 * * * * /usr/bin/ionice -c3 -n7 /bin/nice -n 19 /usr/bin/rsync -ah --stats --delete /home/askapache/wp-content/cache/ /_b/tmpfs/cache/ 1>/dev/null

/tmp, /var/run, and /var/lock

The directories /tmp, /var/run, and /var/lock contain files that are not needed across reboots. This means they are ideal candidates for tmpfs. HEre's how to do it.

tmpfs /var/run tmpfs defaults,rw,nosuid,mode=0755 0 0

tmpfs /var/lock tmpfs defaults,rw,noexec,nosuid,nodev,mode=1777 0 0

Resize /dev/shm

You can view your current /dev/shm size with the command df -ha|grep /dev/shm then if you want to resize that use the command:

mount -t tmpfs -o remount,size-2G,rw,nosuid,nodev tmpfs /dev/shm

Secure /dev/shm:
 
Step 1: Edit your /etc/fstab:
 
nano -w /etc/fstab
 
Locate:
 
none /dev/shm tmpfs defaults,rw 0 0
 
Change it to:
 
none /dev/shm tmpfs defaults,nosuid,noexec,rw 0 0
 
Step 2: Remount /dev/shm:
 
mount -o remount /dev/shm
 
guilt makes extensive use of the '$$' shell variable for temporary
files in /tmp. This is a serious security vulnerability; on multi-user
systems it allows an attacker to clobber files with something like the
following:
 
for i in `seq 1 32768`; do
ln -sf /etc/passwd /tmp/guilt.log.$i;
done
 
(In this example, if root does e.g. 'guilt push', /etc/passwd will get
clobbered.)

Securing and Using /tmp

tmpfs mount parameters

A good way to find a good tmpfs upper-bound is to use top to monitor your system's swap usage during peak usage periods. Then, make sure that you specify a tmpfs upper-bound that's slightly less than the sum of all free swap and free RAM during these peak usage times.

mode=1777 sets sticky bit on directory. Only file owners can delete files in this directory.

The following parameters accept a suffix k, m or g for Ki, Mi, Gi (binary kilo, mega and giga) and can be changed on remount.

size: Override default maximum size of the filesystem. The size is given in bytes, and rounded down to entire pages. The default is half of the memory.The limit of allocated bytes for this tmpfs instance. The default is half of your physical RAM without swap. If you oversize your tmpfs instances the machine will deadlock since the OOM handler will not be able to free that memory.
nr_inodes: Set number of inodes.
nr_blocks: Set number of blocks.
mode: The permissions as an octal number
uid: The user id
gid: The group id

mount -t tmpfs -o size=10G,nr_inodes=10k,mode=700 tmpfs /mytmpfs

Will give you tmpfs instance on /mytmpfs which can allocate 10GB RAM/SWAP in 10240 inodes and it is only accessible by root.

Using tmpfs for /tmp storage

Many users find it very convenient to use tmpfs for /tmp and /var/tmp which does a number of positive things. Any temporary files are instead created in RAM not your hard-drive, which means that reading/writing/accessing those temporary files by various processes doesn't slow down your hard-drive read/writes/accesses for your other processes. This also has a side-effect of making your hard-drive have a longer life as it reduces activity by a huge amount.

Remember that tmpfs uses both RAM and swap, so make sure your machine has a large swapfile, like gigabytes. If your tmpfs consumes all the swap and RAM then you are screwed, so make sure that you correctly set the mount options for the tmpfs so that it doesn't do that. If your /tmp or /var/tmp gets filled with tmp files that for some reason don't get deleted except at reboot, and your machine has a very high uptime, then you will want to run some cron jobs to periodically clean the /tmp and /var/tmp directories of older files...

Here's an example scenario: let's say that we have an existing filesystem mounted at /tmp. However, we decide that we'd like to start using tmpfs for /tmp storage.

with recent 2.4 kernels, you can mount your new /tmp filesystem without getting the "device is busy" error:

mount tmpfs /tmp -t tmpfs -o size=64m

With a single command, your new tmpfs /tmp filesystem is mounted at /tmp, on top of the already-mounted partition, which can no longer be directly accessed. However, while you can't get to the original /tmp, any processes that still have open files on this original filesystem can continue to access them. And, if you umount your tmpfs-based /tmp, your original mounted /tmp filesystem will reappear. In fact, you can mount any number of filesystems to the same mountpoint, and the mountpoint will act like a stack; unmount the current filesystem, and the last-most-recently mounted filesystem will reappear from underneath.

Bind Mounts

Using bind mounts, we can mount all, or even part of an already-mounted filesystem to another location, and have the filesystem accessible from both mountpoints at the same time!

For example, you can use bind mounts to mount your existing /tmp filesystem to /sites/askapache.com/tmp, as follows:

mount --bind /tmp /sites/askapache.com/tmp

Now, if you look inside /sites/askapache.com/tmp, you'll see your /tmp filesystem and all its files. And if you modify a file on your /tmp filesystem, you'll see the modifications in /sites/askapache.com/tmp as well. This is because they are one and the same filesystem; the kernel is simply mapping the filesystem to two different mountpoints for us.

Note that when you mount a filesystem somewhere else, any filesystems that were mounted to mountpoints inside the bind-mounted filesystem will not be moved along. In other words, if you have /tmp/cache on a separate filesystem, the bind mount we performed above will leave /sites/askapache.com/tmp/cache empty. You'll need an additional bind mount command to allow you to browse the contents of /tmp/cache at /sites/askapache.com/tmp/cache:

mount --bind /tmp/cache /sites/askapache.com/tmp/cache

Bind mounting and /dev/shm

glibc 2.2 and above expects tmpfs to be mounted at /dev/shm for POSIX shared memory (shm_open, shm_unlink). Adding the following line to /etc/fstab should take care of this:

tmpfs  /dev/shm  tmpfs  defaults  0 0

Many systems by default have a tmpfs filesystem mounted at /dev/shm that defaults to a size of half of your physical RAM without swap. Say you decide that you'd like to start using tmpfs for /tmp, which currently lives on your root filesystem. Rather than mounting a new tmpfs filesystem to /tmp (which is possible), you may decide that you'd like the new /tmp to share the currently mounted /dev/shm filesystem. However, while you could bind mount /dev/shm to /tmp and be done with it, your /dev/shm contains some directories that you don't want to appear in /tmp. So, what do you do? How about this:

mkdir /dev/shm/tmp
chmod 1777 /dev/shm/tmp
mount --bind /dev/shm/tmp /tmp

In this example, we first create a /dev/shm/tmp directory and then give it 1777 perms, the proper permissions for /tmp. Now that our directory is ready, we can mount /dev/shm/tmp, and only /dev/shm/tmp to /tmp. So, while /tmp/foo would map to /dev/shm/tmp/foo, there's no way for you to access the /dev/shm/bar file from /tmp.

/etc/default/tmpfs WorkAround

$ cat /etc/default/tmpfs
# SHM_SIZE sets the maximum size (in bytes) that the /dev/shm tmpfs can use.
# If this is not set then the size defaults to the value of TMPFS_SIZE
# if that is set; otherwise to the kernel's default.
#
# The size will be rounded down to a multiple of the page size, 4096 bytes.
SHM_SIZE=524288000
# TMPFS_SIZE sets the max size that /dev/shm can use.  By default, the
# kernel sets this upper limit to half of available memory.
TMPFS_SIZE=524288000

RSYNC vs. CP

rsync [options]  SRC DEST
rsync -av --delete --stats /home/wincom/public_html/wp-content/cache/ /backups/tmp-mnt/cache/
-a, --archive               archive mode; same as -rlptgoD (no -H)
-r, --recursive             recurse into directories
-l, --links                 copy symlinks as symlinks
-p, --perms                 preserve permissions
-t, --times                 preserve times
-g, --group                 preserve group
-o, --owner                 preserve owner (super-user only)
-D                          same as --devices --specials
    --devices               preserve device files (super-user only)
    --specials              preserve special files
 -h, --human-readable        output numbers in a human-readable format
     --progress              show progress during transfer

Mount Options

The following options apply to any file system that is being mounted (but not every file system actually honors them)

async All I/O to the file system should be done asynchronously.
atime Update inode access time for each access. This is the default.
auto Can be mounted with the -a option.
defaults Use default options: rw, suid, dev, exec, auto, nouser, and async.
dev Interpret character or block special devices on the file system.
exec Permit execution of binaries.
group Allow an ordinary (i.e., non-root) user to mount the file system if one of his groups matches the group of the device. This option implies the options nosuid and nodev (unless overridden by subsequent options, as in the option line group,dev,suid).
mand Allow mandatory locks on this filesystem. See fcntl(2).
_netdev The filesystem resides on a device that requires network access (used to prevent the system from attempting to mount these filesystems until the network has been enabled on the system).
noatime Do not update inode access times on this file system (e.g, for faster access on the news spool to speed up news servers).
nodiratime Do not update directory inode access times on this filesystem.
noauto Can only be mounted explicitly (i.e., the -a option will not cause the file system to be mounted).
nodev Do not interpret character or block special devices on the file system.
noexec Do not allow direct execution of any binaries on the mounted file system. (Until recently it was possible to run binaries anyway using a command like /lib/ld*.so /mnt/binary. This trick fails since Linux 2.4.25 / 2.6.0.)
nomand Do not allow mandatory locks on this filesystem.
nosuid Do not allow set-user-identifier or set-group-identifier bits to take effect. (This seems safe, but is in fact rather unsafe if you have suidperl(1) installed.)
nouser Forbid an ordinary (i.e., non-root) user to mount the file system. This is the default.
owner Allow an ordinary (i.e., non-root) user to mount the file system if he is the owner of the device. This option implies the options nosuid and nodev (unless overridden by subsequent options, as in the option line owner,dev,suid).
remount Attempt to remount an already-mounted file system. This is commonly used to change the mount flags for a file system, especially to make a readonly file system writeable. It does not change device or mount point.
ro Mount the file system read-only.
_rnetdev Like _netdev, except "fsck -a" checks this filesystem during rc.sysinit.
rw Mount the file system read-write.
suid Allow set-user-identifier or set-group-identifier bits to take effect.
sync All I/O to the file system should be done synchronously. In case of media with limited number of write cycles (e.g. some flash drives) "sync" may cause life-cycle shortening.
dirsync All directory updates within the file system should be done synchronously. This affects the following system calls: creat, link, unlink, symlink, mkdir, rmdir, mknod and rename.
user Allow an ordinary user to mount the file system. The name of the mounting user is written to mtab so that he can unmount the file system again. This option implies the options noexec, nosuid, and nodev (unless overridden by subsequent options, as in the option line user,exec,dev,suid).
users Allow every user to mount and unmount the file system. This option implies the options noexec, nosuid, and nodev (unless overridden by subsequent options, as in the option line users,exec,dev,suid).

Filesystems

You can find out what is filesystems are in place by using one of the following linux commands:

cat /etc/fstab
cat /etc/mtab
cat /proc/mounts
df -a

/etc/fstab

       /etc/fstab        file system table
       /etc/mtab         table of mounted file systems
       /etc/mtab~        lock file
       /etc/mtab.tmp     temporary file
       /etc/filesystems  a list of filesystem types to try

From /etc/mtab

none /tmp tmpfs size=128m,mode=1777 0 0

From /proc/mounts

none /tmp tmpfs rw,nodev,relatime,size=131072k 0 0

/etc/fstab

It is possible that files /etc/mtab and /proc/mounts don’t match. The first file is based only on the mount command options, but the content of the second file also depends on the kernel and others settings (e.g. remote NFS server. In particular case the mount command may reports unreliable information about a NFS mount point and the /proc/mounts file usually contains more reliable information.)

This file is used in three ways:

The following command (usually given in a bootscript) causes all file systems mentioned in fstab (of the proper type and/or having or not having the proper options) to be mounted as indicated, except for those whose line contains the noauto keyword. Adding the -F option will make mount fork, so that the filesystems are mounted simultaneously.
```
mount -a [-t type] [-O optlist]
```
When mounting a file system mentioned in fstab, it suffices to give only the device, or only the mount point.
Normally, only the superuser can mount file systems. However, when fstab contains the user option on a line, anybody can mount the corresponding system.

The programs mount and umount maintain a list of currently mounted file systems in the file /etc/mtab.

Only the user that mounted a filesystem can unmount it again. If any user should be able to unmount, then use users instead of user in the fstab line. The owner option is similar to the user option, with the restriction that the user must be the owner of the special file. The group option is similar, with the restriction that the user must be member of the group of the special file.

The order of records in fstab is important because fsck(8), mount(8), and umount(8) sequentially iterate through fstab doing their thing.

The first field, (fs_spec)

Describes the block special device or remote filesystem to be mounted. For ordinary mounts it will hold (a link to) a block special device node (as created by mknod(8)) for the device to be mounted, like ‘/dev/cdrom’ or ‘/dev/sdb7’. For NFS mounts one will have :

, e.g., ‘knuth.aeb.nl:/’. For procfs, use ‘proc’.

Instead of giving the device explicitly, one may indicate the (ext2 or xfs) filesystem that is to be mounted by its UUID or volume label (cf. e2label(8) or xfs_admin(8)), writing LABEL= or UUID=, e.g., ‘LABEL=Boot’ or ‘UUID=3e6be9de-8139-11d1-9106-a43f08d823a6’. This will make the system more robust: adding or removing a SCSI disk changes the disk device name but not the filesystem volume label.

The second field, (fs_file)

Describes the mount point for the filesystem. For swap partitions, this field should be specified as ‘none’. If the name of the mount point contains spaces these can be escaped as ‘\040’.

The third field, (fs_vfstype), describes the type of the filesystem. Linux supports lots of filesystem types, such as adfs, affs, autofs, coda, coherent, cramfs, devpts, efs, ext2, ext3, hfs, hpfs, iso9660, jfs, minix, msdos, ncpfs, nfs, ntfs, proc, qnx4, reiserfs, romfs, smbfs, sysv, tmpfs, udf, ufs, umsdos, vfat, xenix, xfs, and possibly others. For more details, see mount(8). For the filesystems currently supported by the running kernel, see /proc/filesystems. An entry swap denotes a file or partition to be used for swapping, cf. swapon(8). An entry ignore causes the line to be ignored. This is useful to show disk partitions which are currently unused.

The fourth field, (fs_mntops)

Describes the mount options associated with the filesystem. It is formatted as a comma separated list of options. It contains at least the type of mount plus any additional options appropriate to the filesystem type. For documentation on the available options for non-nfs file systems, see mount(8). For documentation on all nfs-specific options have a look at nfs(5).

Common for all types of file system are the options:

noauto: (do not mount when "mount -a" is given, e.g., at boot time)
user: (allow a user to mount)
owner: (allow device owner to mount)
pamconsole: (allow a user at the console to mount)
comment: (e.g., for use by fstab-maintaining programs).

The fifth field, (fs_freq)

Used for these filesystems by the dump(8) command to determine which filesystems need to be dumped. If the fifth field is not present, a value of zero is returned and dump will assume that the filesystem does not need to be dumped.

The sixth field, (fs_passno)

Used by the fsck(8) program to determine the order in which filesystem checks are done at reboot time. The root filesystem should be specified with a fs_passno of 1, and other filesystems should have a fs_passno of 2. Filesystems within a drive will be checked sequentially, but filesystems on different drives will be checked at the same time to utilize parallelism available in the hardware. If the sixth field is not present or zero, a value of zero is returned and fsck will assume that the filesystem does not need to be checked.

Use tmpfs for MySQL

--tmpdir=path, -t path

The path of the directory to use for creating temporary files. It might be useful if your default /tmp directory resides on a partition that is too small to hold temporary tables. Starting from MySQL 4.1.0, this option accepts several paths that are used in round-robin fashion. Paths should be separated by colon characters (“:”) on Unix and semicolon characters (“;”) on Windows, NetWare, and OS/2. If the MySQL server is acting as a replication slave, you should not set --tmpdir to point to a directory on a memory-based file system or to a directory that is cleared when the server host restarts. For more information about the storage location of temporary files, see Section A.1.4.4, “Where MySQL Stores Temporary Files”. A replication slave needs some of its temporary files to survive a machine restart so that it can replicate temporary tables or LOAD DATA INFILE operations. If files in the temporary file directory are lost when the server restarts, replication fails.

On Unix, MySQL uses the value of the TMPDIR environment variable as the path name of the directory in which to store temporary files. If TMPDIR is not set, MySQL uses the system default, which is usually /tmp, /var/tmp, or /usr/tmp. If the file system containing your temporary file directory is too small, you can use the --tmpdir option to mysqld to specify a directory in a file system where you have enough space. Starting from MySQL 4.1, the --tmpdir option can be set to a list of several paths that are used in round-robin fashion. Paths should be separated by colon characters (“:”) on Unix and semicolon characters (“;”) on Windows, NetWare, and OS/2. Note To spread the load effectively, these paths should be located on different physical disks, not different partitions of the same disk. If the MySQL server is acting as a replication slave, you should not set --tmpdir to point to a directory on a memory-based file system or to a directory that is cleared when the server host restarts. A replication slave needs some of its temporary files to survive a machine restart so that it can replicate temporary tables or LOAD DATA INFILE operations. If files in the temporary file directory are lost when the server restarts, replication fails. MySQL creates all temporary files as hidden files. This ensures that the temporary files are removed if mysqld is terminated. The disadvantage of using hidden files is that you do not see a big temporary file that fills up the file system in which the temporary file directory is located.

Shell Script for Firefox tmpfs

#!/bin/bash
### Bind temporary directories to /dev/shm ###
# I do this instead of mounting tmpfs on the #
# directories, so less memory gets wasted.   #
##############################################
mkdir /dev/shm/{tmp,lock}
mount --bind /dev/shm/tmp /tmp
mount --bind /dev/shm/tmp /var/tmp
mount --bind /dev/shm/lock /var/lock
chmod 1777 /dev/shm/{tmp,lock}

Hey! You made it!@ at least to the bottom of the page.. I still have to finish this article, so check back in a few months.

30x Faster Cache and Site Speed with TMPFS originally appeared on AskApache.com