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Chmod, Umask, Stat, Fileperms, and File Permissions

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

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

HOWTO: Uninstall CPANEL over SSH

AskApache — Mon, 04 Jul 2011 18:55:40 +0000

AskApache.com

WARNING! This is for advanced users of the shell, this is NOT a howto or tutorial. The thing is, I googled how to uninstall cpanel and for once in my life I came up empty.. And certainly the cpanel official sites themselves don't provide any instructions other than to say "Dont uninstall it, reinstall your entire operating system without it.".. they sure don't seem confident that they know exactly what their code is doing. Cpanel is great for most people, perfect for many situations, so don't get me wrong.. this is just for fun.

Why Uninstall?

Why? Because I have always built my servers, php installations, perl installs, ruby, iptables, everything from source. I read the INSTALL/README docs, I read the man pages, and I read the info pages as well. I google for configuration advice, I google for tips, and I don't need a web-based perl script messing my stuff up!

The main problems I had with cpanel, which really is a great bit of software for millions of website developers, is that it was incredibly sneaky! I used it for about 6 months and spent that entire time trying to figure out what the heck it was doing. A couple issues that I really disliked, it takes over your bind install, it takes over your apache install, it takes over your php install. And although it does let you configure some things (very few) for custom configurations and the like, I just don't need any of that. By removing the darn thing I am saving GIGS of space on my server, tons of bandwidth, and most importantly to me I am saving CPU and processing time along with RAM and IO speed.

Anything Else

Please.. I could go on for DAYS! Another reason I have wanted to be rid of cpanel is that I like my servers to be as lean and mean as possible. This means I like as few files and processes as possible. There are many benefits to this, like it's much easier for my integrity checking software and rootkit/antivirus software to run and drastically reduces the false positives. And there is that glaring security issue of constantly having cpanel run it's own software to create the WHM/Cpanel web interface, which is accessible online. I haven't researched cpanel security at all, it's possible that it never has security problems that are published, but for me, why take the chance?

Warning - Caution!

The following is just a quick reference of some of the commands I used to uninstall cpanel. This is for advanced users of the shell. If you aren't that advanced and you run a single one of these commands without fully understanding it, you will probably kill your server, probably lose everything on it permanently, probably not have a website or email for weeks.. So backup all your data FIRST. Also, if you aren't 100% sure you won't run into problems, you should contact your hosts technical support - but be prepared for some MAJOR negativity.. cpanel makes things very easy for hosts, and the last thing tech support wants is to fix a server broken by someone who doesn't know what they are doing.

Last Warning!

Unless you understand what theses commands do and the purpose they serve, do not try any of this. These are not the exact commands I used verbatim, they are also not in order. I only put them up here because I was so amazed that google didn't have any uninstall cpanel intructions. Hopefully it's not a conspiracy that will get my site taken down.. ;)

That said and out of the way, it really only took me about 10 minutes to uninstall cpanel completely. But keep in mind I have been closely monitoring and debugging cpanel for 6 months, so I knew what I was doing. And finally, I do apologize for not having better instructions.. but hey, if you don't get this then you have no business trying to figure out how to uninstall cpanel! It's great software and shouldn't be removed unless you are fully capable of managing email/dns/www/ftp and any/all other servers and services on your machine by hand.

Do This First

I have a few drafts I'm working on at the moment with specifics, but for now you will have to figure it out with google. Basically you want to make sure you don't totally knock your machine offline without being able to reconnect. What I do is compile a static version of openssh and a few other security-type shell tools, and configure this binary sshd to run by using inittab, which is the file run by init (pid 1) and makes sure if it dies it is restarted. Here is my /etc/inittab to run the static sshd binary:

hh:12345:respawn:/failover/os/sbin/aassh -D -q -u0 -f /failover/os/etc/aassh

Another trick is to keep a detached screen logged in to root. That way if you mess up your sudoers or securetty or pam or whatever, you can just reattach and fix it.

Finally, you may want to setup your syslog to start earlier than usual, and set up more than normal verbosity. ( I take it to the max ). Then you should setup a 2nd server or machine somewhere to act as a syslog server. Lastly, configure your web server syslog to copy all messages to the remote syslog you set up. I use a reverse ssh tunnel to encrypt the syslog packets, but when I do something serious like reboot after uninstalling cpanel, I prepare for it by adding additional networking routes on my machine to make sure I will get some logs even if sshd cant start or even if my network addresses aren't brought up correctly.

If that sounds easy to you, please continue. If you are saying: Wha??? Continue in read-only mode.

Also, you can't just uninstall cpanel, I have replaced a lot of cpanel already, like building my own bind, apache, php, syslog and making sure they work and aren't being tampered with by cpanel. Basically cpanel runs everything on your server in most cases, so you should prepare by creating your own static software to replace cpanel, and make sure it works.

Find files Accessing /var/cpanel

More than likely these will need to be killed.

lsof +w -Rg -nP +c15 -x f +D /var/cpanel
lsof +w -Rg -nP +c15 -x f +D /usr/local/cpanel

Killing cpanel

Just an example, your machine may have a lot more than these, I have been slowly taking control of my machine back from cpanel for 6 months, so it was easier for me.

for P in tailwatchd queueprocd cpanellogd exim; do pkill -9 $P; done

Commands and Shortcuts

alias NF='nice find $PWD -mount -depth ! -type d'
alias NFF='nice find $PWD -mount -depth ! -type d | xargs -IF87 file F87'
alias NA='nice find $PWD -mount -depth'
alias NAF='nice find $PWD -mount -depth | xargs -IF87 file F87'

Watch out for crontab

An example of the sneakiness (from my POV, from most it's called builtin robustness) that cpanel does is automagically adding crontab entries that make it behave similarly to a self-propagating virus. If you don't disable the cronjobs and kill the right processes within a short period of time, be prepared for a magic resurrection.

Here's my awesome crontab information function, you will need to check every file, it lists the default crons on my box, and every users crontab, but it can't account for other cron software like at and other crons.

function askapache_crontab()
{
  local GG i;
  for i in `getent passwd|cut -d ":" -f1`;
  do
    GG=$(sudo crontab -u $i -l 2>$N6 | tr -s '\n\000' | sed '/^#/d');
    [[ ${#GG} -gt 3 ]] && sleep 1 && echo -e "$i \n\n${GG}"
  done;
   sleep 4;
   ls -aLls1ch --color=always /etc/cron.{hourly,daily,weekly,monthly,d} | sed '/^total/d; /\ drwxr-xr-x/d';
}

grep -ir /var/spool cpan

#6 3 * * * /scripts/upcp
#0 1 * * * /scripts/cpbackup
#0 2 * * * /scripts/mailman_chown_archives
#35 * * * * /usr/bin/test -x /usr/local/cpanel/bin/tail-check && /usr/local/cpanel/bin/tail-check
#11,26,41,56 * * * * /usr/local/cpanel/whostmgr/bin/dnsqueue > /dev/null 2>&1
#30 */4 * * * /usr/bin/test -x /scripts/update_db_cache && /scripts/update_db_cache
#45 */8 * * * /usr/bin/test -x /usr/local/cpanel/bin/optimizefs && /usr/local/cpanel/bin/optimizefs
#*/5 * * * * /usr/local/cpanel/bin/dcpumon >/dev/null 2>&1
#25 1 * * * /usr/local/cpanel/whostmgr/docroot/cgi/cpaddons_report.pl --notify

Delete Crontabs

sudo crontab -u mailman -r

Find INIT scripts with cpanel

This is the main startup script: /usr/local/cpanel/etc/init/startup

I had no idea ruby-on-rails was being controlled by cpanel.. sneaky bugger. You can tell by all of these advanced unix commands just how difficult it would be to uninstall cpanel, its totally like the Alien!

(1:3744)# find . ! -type d -print0|xargs -0 -I'F87' grep -Hi "cpan\|tailwat\|chkser" F87
./fastmail:# Author:       cPanel, Inc. 
./httpd:        HTTPD=/usr/local/cpanel/bin/chroothttpd
./cpanel:# cpanel8       Start Cpanel Services
./cpanel:# Author:       cPanel, Inc. 
./cpanel:# description: This is the cpanel webserver and chat.
./cpanel:# processname: cpaneld
./cpanel:# pidfile: /var/run/cpanel.pid
./cpanel:[ -f /usr/local/cpanel/etc/init/startup ] || exit 0
./cpanel:       if [ -f "/var/cpanel/smtpgidonlytweak" ]; then
./cpanel:       echo -n "Starting cPanel services: "
./cpanel:       daemon /usr/local/cpanel/etc/init/startcpsrvd
./cpanel:       echo -n "Starting cPanel brute force detector services: "
./cpanel:       daemon /usr/local/cpanel/etc/init/startcphulkd
./cpanel:    echo -n "Starting cPanel dav services: "
./cpanel:       daemon /usr/local/cpanel/etc/init/startcpdavd
./cpanel:               daemon /usr/local/cpanel/etc/init/startcppop
./cpanel:       echo -n "Starting cPanel Chat services: "
./cpanel:               daemon /usr/local/cpanel/entropychat/entropychat
./cpanel:               daemon /usr/local/cpanel/bin/startmelange
./cpanel:                       /usr/local/cpanel/bin/startinterchange
./cpanel:       echo -n "Starting cPanel ssl services: "
./cpanel:       daemon /usr/local/cpanel/startstunnel
./cpanel:    echo -n "Starting cPanel Queue services: "
./cpanel:       daemon /usr/local/cpanel/etc/init/startqueueprocd
./cpanel:    echo -n "Starting tailwatchd: "
./cpanel:    daemon /usr/local/cpanel/libexec/tailwatchd --start
./cpanel:       echo -n "Starting cPanel Log services: "
./cpanel:       daemon /usr/local/cpanel/cpanellogd
./cpanel:    action "Starting mailman services: " /usr/local/cpanel/etc/init/startmailman
./cpanel:    action "Stopping tailwatchd: " /usr/local/cpanel/libexec/tailwatchd --stop
./cpanel:    action "Stopping cPanel services: " /usr/local/cpanel/etc/init/stopcpsrvd
./cpanel:       action "Stopping cPanel dav services: " /usr/local/cpanel/etc/init/stopcpdavd
./cpanel:       action "Stopping cPanel queue services: " /usr/local/cpanel/etc/init/stopqueueprocd
./cpanel:       action "Stopping cPanel brute force detector services: " /usr/local/cpanel/etc/init/stopcphulkd
./cpanel:               action "Stopping pop3 services: " /usr/local/cpanel/etc/init/stopcppop
./cpanel:       echo -n "Stopping cPanel log services: "
./cpanel:       killproc cpanellogd
./cpanel:       echo -n "Stopping cPanel Chat services: "
./cpanel:       action "Stopping cPanel ssl services: " /usr/local/cpanel/etc/init/stopstunnel
./cpanel:       action "Stopping mailman services: " /usr/local/cpanel/etc/init/stopmailman
./cpanel:       if [ -e "/usr/local/cpanel/3rdparty/mailman/bin/mailmanctl" ]; then
./exim:if [ -e "/etc/chkserv.d" ]; then
./exim:        for file in `ls /etc/chkserv.d`
./exim:            if [ ! -e "/usr/local/cpanel/libexec/tailwatchd" ]; then
./exim:    if [ -x "/usr/local/cpanel/etc/init/startspamd" ]; then
./exim:        /usr/local/cpanel/etc/init/startspamd
./exim:        if [ ! -e "/usr/local/cpanel/libexec/tailwatchd" ]; then
./ror:  /usr/local/cpanel/bin/rormgr --startboot
./ror:  /usr/local/cpanel/bin/rormgr --stopall
./ror:  /usr/local/cpanel/bin/rormgr --stopall
./ror:  /usr/local/cpanel/bin/rormgr --startboot
./ror:  /usr/local/cpanel/bin/rormgr --statusall
./securetmp:# Author:       cPanel, Inc.

Turn off cpanel services

You should remove the below delete command and start by just disabling the inits by turning them off. Then reboot. Then delete. If your machine won't reboot, I told you so, Cpanel told you so, and likely your host told you so.

for S in cpanel ror securetmp fastmail exim; do R=$(command chkconfig --level 123456 $S off ||echo); R=$(command chkconfig --del $S ||echo); done

HTTPD

If you are running chrooted httpd then you'll need to make sure you don't delete your entire webserver on accident. Here's a relevant part from the /etc/init.d/httpd script.

# the path to your httpd binary, including options if necessary
if [ -e "/etc/chroothttpd" ]; then
        HTTPD=/usr/local/cpanel/bin/chroothttpd
else
        HTTPD=/usr/local/apache/bin/httpd
fi

Finding files owned by cpanel

Some super cool bash commands in this post.. let's start with one to find all the files and folders on your machine owned by cpanel. Check your /etc/passwd file for your machines specific usernames and groups. This command saves all the filenames to ~/cpanel-files-backup.txt, which is used by tar next to create a backup of all of them.

{ find / -mount -depth -maxdepth 150 \( -group cpanel -o   -group cpanel-phpmyadmin -o -group cpanel-phppgadmin   -o -group cpanelphpmyadmin   -o -group cpanelphppgadmin   -o -group cpanelhorde   -o -group cpanelroundcube \) -print; find / -mount -depth -maxdepth 150 \( -user cpanel -o   -user cpanel-phpmyadmin -o -user cpanel-phppgadmin   -o -user cpanelphpmyadmin   -o -user cpanelphppgadmin   -o -user cpanelhorde   -o -user cpanelroundcube \) -print; } > ~/cpanel-files-backup.txt

Here's another way to search directories.

 grep --color=always -Hir cpanel /var

Create the Backup

Note that you must have the latest version of tar for this exact command, also you should backup /var/cpanel and /usr/local/cpanel and /etc and heck the whole machine why dontcha!

tar -T ~/cpanel-files-backup.txt -cvz --checkpoint=1000 --checkpoint-action="ttyout=\rHit %s checkpoint #%u" -f /cpanel-files-backup.tgz --totals

Remove Files

Once you do this your upstream without a paddle, you better make sure you know what you're doing with this. This removes all those files.

cat ~/cpanel-files-backup.txt | xargs -I'F87' rm -vfr F87

Additionally you will want to remove /usr/local/cpanel and /var/cpanel - What I always do when running as root is alias my rm command to instead simply move the files to a .trash folder. That way if something goes bork you have a better chance at fixing it.

Find Group-Owned Files

find / -mount -depth -maxdepth 150 \
\(  -group cpanel -o \
  -group cpanel-phpmyadmin \
  -o -group cpanel-phppgadmin \
  -o -group cpanelphpmyadmin \
  -o -group cpanelphppgadmin \
  -o -group mailman \
  -o -group cpanelhorde \
  -o -group cpanelroundcube \
\) -fprintf /root/cpanel-group-files.log '%#8k %#5m %11M %#10u:%-10g %-5U:%-5G %p %f %Y %F\n'

Find User-Owned Files

find / -mount -depth -maxdepth 150 \(
  -user cpanel \
  -o -user cpanel-phpmyadmin \
  -o -user cpanel-phppgadmin \
  -o -user cpanelphpmyadmin \
  -o -user cpanelphppgadmin \
  -o -user mailman \
  -o -user cpanelhorde \
  -o -user cpanelroundcube
\) -fprintf /root/cpanel-users-files.log '%#8k %#5m %11M %#10u:%-10g %-5U:%-5G %p %f %Y %F\n'

       4  0755  drwxr-xr-x     cpanel:cpanel     32002:32004 /var/cpanel/userhomes/cpanel cpanel d reiserfs
       4  0700  drwx------ cpanel-phpmyadmin:cpanel-phpmyadmin 32005:32007 /var/cpanel/userhomes/cpanel-phpmyadmin/tmp tmp d reiserfs
       4  0644  -rw-r--r-- cpanel-phpmyadmin:cpanel-phpmyadmin 32005:32007 /var/cpanel/userhomes/cpanel-phpmyadmin/.cpanel/caches/featurelists/default.cache default.cache f reiserfs
       4  0700  drwx------ cpanel-phpmyadmin:cpanel-phpmyadmin 32005:32007 /var/cpanel/userhomes/cpanel-phpmyadmin/.cpanel/caches/featurelists featurelists d reiserfs
       4  0700  drwx------ cpanel-phpmyadmin:cpanel-phpmyadmin 32005:32007 /var/cpanel/userhomes/cpanel-phpmyadmin/.cpanel/caches caches d reiserfs
       4  0700  drwx------ cpanel-phpmyadmin:cpanel-phpmyadmin 32005:32007 /var/cpanel/userhomes/cpanel-phpmyadmin/.cpanel .cpanel d reiserfs
       4  0750  drwxr-x--- cpanel-phpmyadmin:cpanel-phpmyadmin 32005:32007 /var/cpanel/userhomes/cpanel-phpmyadmin/mail mail d reiserfs
       4  0711  drwx--x--x cpanel-phpmyadmin:cpanel-phpmyadmin 32005:32007 /var/cpanel/userhomes/cpanel-phpmyadmin cpanel-phpmyadmin d reiserfs
       4  0700  drwx------ cpanelphppgadmin:cpanelphppgadmin 32009:32011 /var/cpanel/userhomes/cpanelphppgadmin/sessions sessions d reiserfs
       4  0644  -rw-r--r-- cpanelphppgadmin:cpanelphppgadmin 32009:32011 /var/cpanel/userhomes/cpanelphppgadmin/.cpanel/caches/featurelists/default.cache default.cache f reiserfs
       4  0700  drwx------ cpanelphppgadmin:cpanelphppgadmin 32009:32011 /var/cpanel/userhomes/cpanelphppgadmin/.cpanel/caches/featurelists featurelists d reiserfs
       4  0700  drwx------ cpanelphppgadmin:cpanelphppgadmin 32009:32011 /var/cpanel/userhomes/cpanelphppgadmin/.cpanel/caches caches d reiserfs
       4  0700  drwx------ cpanelphppgadmin:cpanelphppgadmin 32009:32011 /var/cpanel/userhomes/cpanelphppgadmin/.cpanel .cpanel d reiserfs
       4  0750  drwxr-x--- cpanelphppgadmin:cpanelphppgadmin 32009:32011 /var/cpanel/userhomes/cpanelphppgadmin/mail mail d reiserfs
       4  0711  drwx--x--x cpanelphppgadmin:cpanelphppgadmin 32009:32011 /var/cpanel/userhomes/cpanelphppgadmin cpanelphppgadmin d reiserfs
       4  0750  drwxr-x--- cpanelroundcube:cpanelroundcube 514  :514   /var/cpanel/userhomes/cpanelroundcube/mail mail d reiserfs
       4  0700  drwx------ cpanelroundcube:cpanelroundcube 514  :514   /var/cpanel/userhomes/cpanelroundcube/sessions sessions d reiserfs
       4  0711  drwx--x--x cpanelroundcube:cpanelroundcube 514  :514   /var/cpanel/userhomes/cpanelroundcube cpanelroundcube d reiserfs
       4  0644  -rw-r--r--     cpanel:cpanel     32002:32004 /var/cpanel/.cpanel/caches/featurelists/default.cache default.cache f reiserfs
       4  0700  drwx------     cpanel:cpanel     32002:32004 /var/cpanel/.cpanel/caches/featurelists featurelists d reiserfs
       4  0700  drwx------     cpanel:cpanel     32002:32004 /var/cpanel/.cpanel/caches caches d reiserfs
       4  0700  drwx------     cpanel:cpanel     32002:32004 /var/cpanel/.cpanel .cpanel d reiserfs
       4  0700  drwx------ cpanelroundcube:cpanelroundcube 514  :514   /var/cpanel/roundcube/tmp tmp d reiserfs
       4  0700  drwx------ cpanelroundcube:cpanelroundcube 514  :514   /var/cpanel/roundcube/log log d reiserfs

Find Permissions

cat ~/cpanel-group-files.log ~/cpanel-users-files.log |tr -s '\000 \t'|cut -d' ' -f3|sort -u

Find files tailwatchd

(1:3732)# $NICE find ${1:-`pwd`} -mount -name '*tailwatch*'
/usr/local/cpanel/libexec/tailwatchd
/usr/local/cpanel/libexec/tailwatch
/usr/local/cpanel/libexec/tailwatch/tailwatchd
/usr/local/cpanel/etc/init/scripts/freebsd/tailwatchd.sh
/usr/local/cpanel/etc/init/scripts/trustix/tailwatchd
/usr/local/cpanel/etc/init/scripts/centos/tailwatchd
/usr/local/cpanel/etc/init/scripts/suse/tailwatchd
/usr/local/cpanel/etc/init/scripts/caos/tailwatchd
/usr/local/cpanel/etc/init/scripts/whitebox/tailwatchd
/usr/local/cpanel/etc/init/scripts/mandrake/tailwatchd
/usr/local/cpanel/etc/init/scripts/debian/tailwatchd
/usr/local/cpanel/etc/init/scripts/redhat/tailwatchd
/usr/local/cpanel/etc/init/scripts/fedora/tailwatchd
/usr/local/cpanel/etc/init/stoptailwatchd
/usr/local/cpanel/etc/init/starttailwatchd
/usr/local/cpanel/bin/tailwatchd
/usr/local/cpanel/logs/tailwatchd_log
/var/log/cpanel/tailwatchd_log
/var/cpanel/log_rotation/cp_tailwatchd_log.cpanellogd
/var/cpanel/tailwatch.positions
/var/run/tailwatchd.pid
/etc/chkserv.d/tailwatchd
/scripts/restartsrv_tailwatchd

Delete cpanel Users/Groups

for U in cpanel-phpmyadmin cpanel-phppgadmin cpanelphpmyadmin cpanelphppgadmin cpanelhorde cpanelroundcube machbuild; do userdel -fr $U; groupdel $U; done

Check for broken symlinks

find / -mount -depth -type l -print0 |xargs -0 -P0 -I'F87' file -s 'F87' | sed -n '/: broken symbolic link to/p'

Especially check /etc

$ find /etc -mount -depth -type l -print0 |xargs -0 -P0 -I'F87' file -s 'F87' | sed -n '/: broken symbolic link to/p'
/etc/ftpd-rsa.pem                   broken symbolic link to `/var/cpanel/ssl/ftp/ftpd-rsa.pem'
/etc/rc.d/rc1.d/K10chkservd         broken symbolic link to `../init.d/chkservd'
/etc/rc.d/rc1.d/K30antirelayd       broken symbolic link to `../init.d/antirelayd'
/etc/rc.d/rc1.d/K80dcc              broken symbolic link to `../init.d/dcc'
/etc/rc.d/rc3.d/K80dcc              broken symbolic link to `../init.d/dcc'
/etc/rc.d/rc3.d/S80chkservd         broken symbolic link to `../init.d/chkservd'
/etc/rc.d/rc3.d/S80antirelayd       broken symbolic link to `../init.d/antirelayd'
/etc/rc.d/rc6.d/K10chkservd         broken symbolic link to `../init.d/chkservd'
/etc/rc.d/rc6.d/K30antirelayd       broken symbolic link to `../init.d/antirelayd'
/etc/rc.d/rc6.d/K80dcc              broken symbolic link to `../init.d/dcc'
/etc/rc.d/rc5.d/K80dcc              broken symbolic link to `../init.d/dcc'
/etc/rc.d/rc5.d/S80chkservd         broken symbolic link to `../init.d/chkservd'
/etc/rc.d/rc5.d/S80antirelayd       broken symbolic link to `../init.d/antirelayd'
/etc/rc.d/rc2.d/K80dcc              broken symbolic link to `../init.d/dcc'
/etc/rc.d/rc2.d/S80chkservd         broken symbolic link to `../init.d/chkservd'
/etc/rc.d/rc2.d/S80antirelayd       broken symbolic link to `../init.d/antirelayd'
/etc/rc.d/rc4.d/K80dcc              broken symbolic link to `../init.d/dcc'
/etc/rc.d/rc4.d/S80chkservd         broken symbolic link to `../init.d/chkservd'
/etc/rc.d/rc4.d/S80antirelayd       broken symbolic link to `../init.d/antirelayd'
/etc/rc.d/rc0.d/K10chkservd         broken symbolic link to `../init.d/chkservd'
/etc/rc.d/rc0.d/K30antirelayd       broken symbolic link to `../init.d/antirelayd'
/etc/rc.d/rc0.d/K80dcc              broken symbolic link to `../init.d/dcc'
/etc/authlib/authProg               broken symbolic link to `/usr/local/cpanel/bin/courier-auth'

And delete if you are sure

find /etc -mount -depth -type l -print0 |xargs -0 -P0 -I'F87' file -s 'F87' | sed -n '/: broken symbolic link to/p' |cut -d' ' -f1|xargs -I'F87' rm -rvf 'F87'

Reinstall CSF

The only thing I actually used that came with cpanel is the CSF/LFD Firewall package, which is a fantastic piece of software. I had to reinstall this, and to get it working without cpanel add the following line to the csf.conf

GENERIC = "1"

Thats It

Now once you've cleaned up everything, you should try everything conceivable to get an error before rebooting. Like you should start and stop every service in /etc/init.d/, you should use telinit to check various runlevels (which keeps your sshd connection still live). Go all out, should take at least a full hour.

Another thing I like to do is rebuild alot of my source-built software again in case anything got messed up. I upgrade perl from cpanels 5.8.8 to 5.10, which is pretty thorough, and you know, reinstall anything else I think I might need. One of the benefits of compiling your own software is all I have to do is cd to the source directory and type make -B && ( { make test || make check || make checks || make tests; } || echo ) && sudo make install and that's it. The tests/checks are optional of course.

If anyone actually ever reads this and does it, please share your advice here.. everybody knows we need it! Good Luck

HOWTO: Uninstall CPANEL over SSH originally appeared on AskApache.com

Enhanced printenv Script for Server Debugging

AskApache — Thu, 14 Apr 2011 19:05:17 +0000

AskApache.com

Every Apache server comes pre-shipped with an old cgi script named printenv. It's useful and used for printing out the environment variables from your servers point of view. Basically you save this file where you can then call it from your browser, like site.com/printenv.cgi -- then it will be executing as the user running the web server, nobody, apache, etc.. So this tells you all sorts of interesting things about your server, especially if you want/need to know about the users, groups, and file permissions.

Enabling CGI

You need to do 1 of 2 things to use this:

Make it executable and in your server directory
Use a trick to cause your server to execute it regardless

Htaccess CGI

If you have htaccess then you most likely can get this to work by giving it an execute bit with chmod or from your ftp client, and then use htaccess like this:

Options +ExecCGI Indexes +FollowSymLinks
AddHandler cgi-script .cgi .pl .sh
 
Order Deny,Allow
Deny from All
Allow from 127.0.0.1 ADDYOURIPHERE env=REDIRECT_STATUS
Satisfy All

Search around on this site for php.cgi tricks if you can't seem to get it. Basically you can try stuff like making it an errordocument, using other directives like forcetype, AddType, and even try stuff like mod_security's upload binary setting.

You do not want anyone other than you ever looking at the output of this. It's so full of details about your machine that it would be a huge security problem.

The AskApache Printenv

#!/bin/sh
echo -e "Content-type: text/plain\n\n"
 
# FUNCTIONS
################################################################################################################
function __A ()
{ local __a __i __z;for __a;do __z=\${!${__a}*};for __i in `eval echo "${__z}"`;do echo -e "$__i: ${!__i}";done;done; }
 
function __S ()
{ local L IFS=';';while read -r L;do builtin printf "${#L}@%s\n" "$L";done|sort -n|sed -u 's/^[^@]*//'; }
 
function __P ()
{ local l=`builtin printf %${2:-$__WIDTH}s` && echo -e "${l// /${1:-=}}"; }
 
function __T ()
{ echo -e "\n\n+`__P -`+\n| $*\n+`__P '='`+"; }
 
function __M ()
{ echo -e " >>> $M" $*; }
 
function __H ()
{ command builtin type $1 &>/dev/null && local a="yes" || return 1; }
 
function LE ()
{
 [[ ! -r /proc/${1:-$$}/limits ]] && return;
 sed -e '1z;s/ *$//;:a;$!N;s/\nM.. [a-z]* [a-z]* [a-z]* \{1,\}\([^ ]*\) *\([^ ]*\) *[a-z]* */\1:\2 /;ta;s/u\w\+d/u/g;s/ *$//;s/ / | /g;s/\([^:]\+\):\1/\1:=/g' /proc/${1:-$$}/limits;
}
function LH ()
{
 [[ ! -r /proc/${1:-$$}/limits ]] && return;
 sed -e '1z;s/ *$//;:a;$!N;s/\nM.. \([a-z]\+ [a-z]* [a-z]*\) \{1,\}\([^ ]*\) *\([^ ]*\) *\([a-z]*\) */:\1/;ta;s/ *:/:/g;s/size/sz/g;s/file/f/g;s/ p\w\+y/ pri/g;s/memory/mem/g;s/p\w\+s/procs/g;s/^://;s/:/ | /g' /proc/${1:-$$}/limits
}
 
# CUSTOM SETTINGS
################################################################################################################
__WIDTH=170
LC_COLLATE=C LC_CTYPE=C LC_ALL=C
 
# RUNTIME SETUP
#################################################################################################################
shopt -s dotglob nocaseglob extglob
 
# -C If set, disallow existing regular files to be overwritte
# -f Disable file name generation (globbing
# -e Exit immediately if a command exits with a non-zero status
# -B enable brace expansion
# +H disable History
set -C +f +H -B
 
# make sure we dont create any files
umask 0177
 
# redirect everything to output (no logs or stderr is used)
exec 2>/dev/null
 
# MAIN EXECUTION
#################################################################################################################
{
 __T "EXPANDING PATH"
 {
  __M "ORIG PATH:$PATH"
  PATH=$PATH:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/usr/libexec:/usr/local/apache/bin
  for t in ${PATH//:/ };
  do
   [[ -d "$t" ]] && sed -n -e "/:${t//\//\\/}:/Q1" <<< ":${p:=}:" && p=$p:$t || continue;
  done
  PATH=${p/:/}:.
  __M "NEW PATH:$PATH"
 }
 
 __T "USER INFO"
 {
  __M "UMASK: `(umask 2>/dev/null)` ( `(umask -S 2>/dev/null)` )"
  __H uname && __M "UNAME: `eval echo $(uname -a 2>/dev/null)`"
  __H whoami && __M "WHOAMI: `(whoami 2>/dev/null)`"
  __H id && __M "ID: `(id 2>/dev/null)`"
  __H logname && __M "LOGNAME: `(logname 2>/dev/null)`"
  __H groups && __M "GROUPS: `(groups 2>/dev/null)`"
  echo -e "\n\n"
 }
 
 if __H who;
 then
  __T "LOGGED ON USERS"
  {
   (who -a 2>/dev/null)
  }
 fi;
 
 if [[ -r /etc/passwd ]];
 then
  __T "/etc/passwd"
  {
   (cat /etc/passwd)
  }
 fi;
 
 if __H ulimit;
 then
  __T "USER LIMITS"
  {
   ulimit -a
  }
 fi
 
 if [[ -d /dev ]] && __H ls;
 then
  __T "/dev Directory"
  {
   ( ls -vlaph /dev 2>/dev/null )
  }
 fi;
 
 if [[ -d /proc ]];
 then
  __T "CURRENT PROCESS LIMITS"
  {
   for p in `echo /proc/[0-9]*/limits`
   do
    pid=${p:6:$((${#p}-13))}
    [[ $pid == $PPID || $pid == $$ ]] && continue;
    echo -e "\n/proc/$pid:"
    sed '1s/\x00/ /g;n;s/\x00/\n/g;/.\{2,\}/!d' /proc/$pid/cmdline $p 2>/dev/null
   done
  }
 
  __T "CURRENT PROCESS CMDLINE"
  {
   for p in `echo /proc/[0-9]*/cmdline`;
   do
    pid=${p:6:$((${#p}-13))}
    [[ $pid == $PPID || $pid == $$ ]] && continue;
    __M "[ /proc/$pid ]";
    sed 's/\x00/ /g;G' $p 2>/dev/null
   done
  }
 fi
 
 __T "IP INFORMATION"
 {
  __H ip && __M "IP:" && (ip -o -f inet addr 2>/dev/null) | sed 's/^.*inet \([0-9.]*\).*$/\1/g';
  __H nmap && __M "NMAP:" && (nmap --iflist 2>/dev/null) | sed 1,4d | sed -n '/ethernet/s/^.*) \([0-9.]*\).*$/\1/gp';
  __H ifconfig && __M "IFCONFIG:" && (ifconfig -a 2>/dev/null) | sed -n '/inet a/s/^.*addr:\([0-9.]*\).*$/\1/gp';
  [[ -f "$HOME/.cpanel/datastore/_sbin_ifconfig_-a" ]] && __M "CPANEL CACHE:" && sed -e '/inet/!d; s/.*addr:\([0-9\.]*\).*/\1/g' "$HOME/.cpanel/datastore/_sbin_ifconfig_-a" | sort -u
 }
 
 __T "ROUTE / INTERFACE INFO"
 {
  __H route && __M "ROUTE" && (route -nv 2>/dev/null)
  __H ip && ( ip rule && ip route && ip address ) 2>/dev/null
  __H ifconfig && (ifconfig -a 2>/dev/null)
 }
 
 __T "CGI/1.0 test script report:"
 {
  __A SERVER REQUEST GET SERVER PATH REMOTE AUTH CONTENT HTTP TZ GATEWAY QUERY MO
  echo -e "\n\n"
 }
 
 __T "HIDDEN VARIABLES"
 {
  __A {a..z} {A..Z} _{0..9} _{A..Z} _{a..z} | cat -Tsv 2>/dev/null
  echo -e "\n\n"
 }
 
 __T "DECLARE INFO"
 {
  for i in "r" "i" "a" "x" "t" "-";
  do
   builtin eval declare -$i && echo;
  done | sed 's/^declare //' | cat -Tsv 2>/dev/null
  echo -e "\n\n"
 }
 
 __T "SHELL OPTIONS"
 {
  __A SHELLOPTS BASHOPTS
  echo -e "\$-: $-"
  __P '-' && builtin shopt -s -p
  __P '-' && builtin shopt -u -p
  echo -e "\n\n"
 }
 
 __T "ENV AND EXPORT"
 {
  __H env && command env | cat -Tsv 2>/dev/null && __P '-'
  builtin export | cat -Tsv 2>/dev/null
  echo -e "\n\n"
 }
 
 if __H perl;
 then
  __T "PERL VARIABLES"
  {
   perl -e'foreach $v (sort(keys(%ENV))) {$vv = $ENV{$v};$vv =~ s|\n|\\n|g;$vv =~ s|"|\\"|g;print "${v}=\"${vv}\"\n"}' | cat -Tsv 2>/dev/null
   echo -e "\n\n"
  }
 fi
 
} | fold - -w$(($__WIDTH+3))
exit $?

Enhanced printenv Script for Server Debugging originally appeared on AskApache.com

Htaccess Rewrites – Rewrite Tricks and Tips

AskApache — Sun, 10 Apr 2011 14:05:00 +0000

AskApache.com

Htaccess Rewrites are enabled by using the Apache module mod_rewrite, which is one of the most powerful Apache modules and features availale. Htaccess Rewrites through mod_rewrite provide the special ability to Rewrite requests internally as well as Redirect request externally.

When the url in your browser's location bar stays the same for a request it is an internal rewrite, when the url changes an external redirection is taking place. This is one of the first, and one of the biggest mental-blocks people have when learning about mod_rewrite... But I have a secret weapon for you to use, a new discovery from years of research that makes learning mod_rewrite drastically quicker and easier. It truly does or I wouldn't be saying so in the introduction of this article.

Despite the tons of examples and docs, mod_rewrite is voodoo. Damned cool voodoo, but still voodoo.
-- Brian Moore

Note: After years of fighting to learn my way through rewriting urls with mod_rewrite, I finally had a breakthrough and found a way to outsmart the difficulty of mod_rewrite that I just couldn't seem to master. The Mod_Rewrite RewriteCond/RewriteRule Variable Value Cheatsheet is the one-of-a-kind tool that changed the game for me and made mod_rewriting no-harder than anything else.

So keep that mod_rewrite reference bookmarked and you will be able to figure out any RewriteRule or RewriteCond, an amazing feat considering it took me a LONG time to figure this stuff out on my own. But that was before the craziness, one of the most challenging and productive .htaccess experiments I've done... An experiment so ILL it's sick like a diamond disease on your wrist! $$$. That mod_rewrite experiment/tutorial was the culmination of many different advanced mod_rewrite experiments I had done in the past and included most of my very best .htaccess tricks. With the cheatsheet it's no longer Voodoo.. Its just what you do. Now lets dig in!

If you really want to take a look, check out the mod_rewrite.c and mod_rewrite.h files.

Be aware that mod_rewrite (RewriteRule, RewriteBase, and RewriteCond) code is executed for each and every HTTP request that accesses a file in or below the directory where the code resides, so it's always good to limit the code to certain circumstances if readily identifiable.

For example, to limit the next 5 RewriteRules to only be applied to .html and .php files, you can use the following code, which tests if the url does not end in .html or .php and if it doesn't, it will skip the next 5 RewriteRules.

RewriteRule !\.(html|php)$ - [S=5]
RewriteRule ^.*-(vf12|vf13|vf5|vf35|vf1|vf10|vf33|vf8).+$ - [S=1]

.htaccess rewrite examples should begin with:

Options +FollowSymLinks
 
RewriteEngine On
RewriteBase /

Require the www

Options +FollowSymLinks
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^www\.askapache\.com$ [NC]
RewriteRule ^(.*)$ http://www.askapache.com/$1 [R=301,L]

Loop Stopping Code

Sometimes your rewrites cause infinite loops, stop it with one of these rewrite code snippets.

RewriteCond %{REQUEST_URI} ^/(stats/|missing\.html|failed_auth\.html|error/).* [NC]
RewriteRule .* - [L]
 
RewriteCond %{ENV:REDIRECT_STATUS} 200
RewriteRule .* - [L]

Cache-Friendly File Names

This is probably my favorite, and I use it on every site I work on. It allows me to update my javascript and css files in my visitors cache's simply by naming them differently in the html, on the server they stay the same name. This rewrites all files for /zap/j/anything-anynumber.js to /zap/j/anything.js and /zap/c/anything-anynumber.css to /zap/c/anything.css

RewriteRule ^zap/(j|c)/([a-z]+)-([0-9]+)\.(js|css)$ /zap/$1/$2.$4 [L]

SEO friendly link for non-flash browsers

When you use flash on your site and you properly supply a link to download flash that shows up for non-flash aware browsers, it is nice to use a shortcut to keep your code clean and your external links to a minimum. This code allows me to link to site.com/getflash/ for non-flash aware browsers.

RewriteRule ^getflash/?$ http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash [NC,L,R=307]

Removing the Query_String

On many sites, the page will be displayed for both page.html and page.html?anything=anything, which hurts your SEO with duplicate content. An easy way to fix this issue is to redirect external requests containing a query string to the same uri without the query_string.

RewriteCond %{THE_REQUEST} ^GET\ /.*\;.*\ HTTP/
RewriteCond %{QUERY_STRING} !^$
RewriteRule .* http://www.askapache.com%{REQUEST_URI}? [R=301,L]

Sending requests to a php script

This .htaccess rewrite example invisibly rewrites requests for all Adobe pdf files to be handled by /cgi-bin/pdf-script.php

RewriteRule ^(.+)\.pdf$  /cgi-bin/pdf-script.php?file=$1.pdf [L,NC,QSA]

Setting the language variable based on Client

For sites using multiviews or with multiple language capabilities, it is nice to be able to send the correct language automatically based on the clients preferred language.

RewriteCond %{HTTP:Accept-Language} ^.*(de|es|fr|it|ja|ru|en).*$ [NC]
RewriteRule ^(.*)$ - [env=prefer-language:%1]

Deny Access To Everyone Except PHP fopen

This allows access to all files by php fopen, but denies anyone else.

RewriteEngine On
RewriteBase /
RewriteCond %{THE_REQUEST} ^.+$ [NC]
RewriteRule .* - [F,L]

If you are looking for ways to block or deny specific requests/visitors, then you should definately read Blacklist with mod_rewrite. I give it a 10/10

Deny access to anything in a subfolder except php fopen

This can be very handy if you want to serve media files or special downloads but only through a php proxy script.

RewriteEngine On
RewriteBase /
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /([^/]+)/.*\ HTTP [NC]
RewriteRule .* - [F,L]

Require no www

Options +FollowSymLinks
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^askapache\.com$ [NC]
RewriteRule ^(.*)$ http://askapache.com/$1 [R=301,L]

Check for a key in QUERY_STRING

Uses a RewriteCond Directive to check QUERY_STRING for passkey, if it doesn't find it it redirects all requests for anything in the /logged-in/ directory to the /login.php script.

RewriteEngine On
RewriteBase /
RewriteCond %{QUERY_STRING} !passkey
RewriteRule ^/logged-in/(.*)$ /login.php [L]

Removes the QUERY_STRING from the URL

If the QUERY_STRING has any value at all besides blank than the?at the end of /login.php? tells mod_rewrite to remove the QUERY_STRING from login.php and redirect.

RewriteEngine On
RewriteBase /
RewriteCond %{QUERY_STRING} .
RewriteRule ^login.php /login.php? [L]

Fix for infinite loops

An error message related to this isRequest exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace.or you may seeRequest exceeded the limit,probable configuration error,Use 'LogLevel debug' to get a backtrace, orUse 'LimitInternalRecursion' to increase the limit if necessary

RewriteCond %{ENV:REDIRECT_STATUS} 200
RewriteRule .* - [L]

External Redirect .php files to .html files (SEO friendly)

RewriteRule ^(.*)\.php$ /$1.html [R=301,L]

Internal Redirect .php files to .html files (SEO friendly)

Redirects all files that end in .html to be served from filename.php so it looks like all your pages are .html but really they are .php

RewriteRule ^(.*)\.html$ $1.php [R=301,L]

block access to files during certain hours of the day

Options +FollowSymLinks
RewriteEngine On
RewriteBase /
# If the hour is 16 (4 PM) Then deny all access
RewriteCond %{TIME_HOUR} ^16$
RewriteRule ^.*$ - [F,L]

Rewrite underscores to hyphens for SEO URL

Converts all underscores "_" in urls to hyphens "-" for SEO benefits... See the full article for more info.

Options +FollowSymLinks
RewriteEngine On
RewriteBase /
 
RewriteRule !\.(html|php)$ - [S=4]
RewriteRule ^([^_]*)_([^_]*)_([^_]*)_([^_]*)_(.*)$ $1-$2-$3-$4-$5 [E=uscor:Yes]
RewriteRule ^([^_]*)_([^_]*)_([^_]*)_(.*)$ $1-$2-$3-$4 [E=uscor:Yes]
RewriteRule ^([^_]*)_([^_]*)_(.*)$ $1-$2-$3 [E=uscor:Yes]
RewriteRule ^([^_]*)_(.*)$ $1-$2 [E=uscor:Yes]
 
RewriteCond %{ENV:uscor} ^Yes$
RewriteRule (.*) http://d.com/$1 [R=301,L]

Require the www without hardcoding

Options +FollowSymLinks
RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} !^www\.[a-z-]+\.[a-z]{2,6} [NC]
RewriteCond %{HTTP_HOST} ([a-z-]+\.[a-z]{2,6})$     [NC]
RewriteRule ^/(.*)$ http://%1/$1 [R=301,L]

Require no subdomain

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} \.([a-z-]+\.[a-z]{2,6})$ [NC]
RewriteRule ^/(.*)$ http://%1/$1 [R=301,L]

Require no subdomain

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} \.([^\.]+\.[^\.0-9]+)$
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]

Redirecting WordPress Feeds to Feedburner

Full article:Redirecting WordPress Feeds to Feedburner

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_URI} ^/feed\.gif$
RewriteRule .* - [L]
 
RewriteCond %{HTTP_USER_AGENT} !^.*(FeedBurner|FeedValidator) [NC]
RewriteRule ^feed/?.*$ http://feeds.feedburner.com/apache/htaccess [L,R=302]
 
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

Only allow GET and PUT Request Methods

Article: Request Methods

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_METHOD} !^(GET|PUT)
RewriteRule .* - [F]

Prevent Files image/file hotlinking and bandwidth stealing

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?askapache.com/.*$ [NC]
RewriteRule \.(gif|jpg|swf|flv|png)$ /feed/ [R=302,L]

Stop browser prefetching

RewriteEngine On
SetEnvIfNoCase X-Forwarded-For .+ proxy=yes
SetEnvIfNoCase X-moz prefetch no_access=yes
 
# block pre-fetch requests with X-moz headers
RewriteCond %{ENV:no_access} yes
RewriteRule .* - [F,L]

This module uses a rule-based rewriting engine (based on a regular-expression parser) to rewrite requested URLs on the fly. It supports an unlimited number of rules and an unlimited number of attached rule conditions for each rule, to provide a really flexible and powerful URL manipulation mechanism. The URL manipulations can depend on various tests, of server variables, environment variables, HTTP headers, or time stamps. Even external database lookups in various formats can be used to achieve highly granular URL matching.

This module operates on the full URLs (including the path-info part) both in per-server context (httpd.conf) and per-directory context (.htaccess) and can generate query-string parts on result. The rewritten result can lead to internal sub-processing, external request redirection or even to an internal proxy throughput.

Further details, discussion, and examples, are provided in the detailed mod_rewrite documentation.

Directives

If you aren't already comfortable using mod_rewrite then I recommend this excellent mod_rewrite guide by one of my favorite mod_rewrite gurus that I've met.

htaccess Guide Sections

« Search Engine Friendly Redirects | .htaccess Tutorial Index | » Speed up your site with Caching and cache-control

Htaccess Rewrites – Rewrite Tricks and Tips originally appeared on AskApache.com

Advanced Linux Debugging using a Bootloader (GRUB)

AskApache — Thu, 07 Apr 2011 16:35:41 +0000

AskApache.com

This is part of the GRUB article on the Arch Linux wiki that I contributed. As of now, just a copy.

The grub menu.lst provides for a convenient way to add a number of entries with extended kernel parameters to configure all sorts of advanced settings to enable you to quickly and conveniently boot into your existing system with varying levels of debugging output. It's very easy and useful to create several levels of debugging just by adding additional entries to your grub configuration. And if you ever have issues or problems down the road due to a power-failure or hardware failure, it can save you hours of trouble, and of course nothing can beat debugging output when it comes to learning about your system.

Useful Menu.lst Entries

If you are interested in debugging, then you deserve some grub entries for powerusers, here are a few that I like (just add to your menu.lst).

title Shutdown the Computer
halt
 
title Reboot the Computer
reboot
 
title Command Line
commandline
 
title Install GRUB to hd0 MBR
root (hd0,0)
setup (hd0)
 
title Matrix
color green/black light-green/green
 
title Scan for /boot/grub/menu.lst
find --set-root --ignore-floppies /boot/grub/menu.lst
configfile /boot/grub/menu.lst
 
title Scan for /boot/menu.lst
find --set-root --ignore-floppies /menu.lst
configfile /boot/menu.lst
 
# http://www.vortex.prodigynet.co.uk/x86test/
title    Run x86test (CPU Info)
kernel /boot/x86test_zImage.bin
#wget http://www.vortex.prodigynet.co.uk/x86test/x86test_zImage.bin
 
# http://www.memtest.org/
title    Run memtest86+ (Memory Testing)
kernel /boot/memtest86+-1.70.bin

Light Debug

A quick way to see more verbose messages on your console is to bootup your normal grub entry after appending verbose to the kernel line. This simple word added to your kernel line turns on more logging thanks to the /etc/rc.sysinit file, which at the top of the file runs:

if /bin/grep -q " verbose" /proc/cmdline; then /bin/dmesg -n 8; fi

Very simple way to get a bit more messages and debug output in your logs.

title  Arch Linux DEBUG Light
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait verbose
initrd /kernel26.img

Medium Debug

This example menu.lst entry turns on real logging that is set by the kernel and not in an init script. Adding the debug kernel parameter to your kernel line is recognized by a lot of linux internals and enables quite a bit of debugging compared to the default.

title Arch Linux DEBUG Medium
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootdelay=5 panic=10 debug
initrd /kernel26.img

Heavy Debug

An even more impressive kernel parameter is the ignore_loglevel, which causes the system to ignore any loglevel and keeps the internal loglevel at the maximum debugging level, basically rendering dmesg unable to lower the debug level.

title Arch Linux DEBUG Heavy
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootdelay=5 panic=10 debug ignore_loglevel
initrd /kernel26.img

Extreme Debug

If the "Heavy Debug" seemed like a lot of output, thats about 1/2 of the logging that occurs with this example. This does a couple things, it uses the earlyprintk parameter to setup your kernel for "early" "printing" of messages to your "vga" screen. The ,keep just lets it stay on the screen longer. This will let you see logs that normally are hidden due to the boot-up process. This also changes the log buffer length to 10MB, and also instructs that any fatal signals be printed with print_fatal_signals. The last one, sched_debug, you can look up in the very excellent kernel documentation on kernel parameters.

title Arch Linux DEBUG Extreme
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro debug ignore_loglevel log_buf_len=10M print_fatal_signals=1 LOGLEVEL=8 earlyprintk=vga,keep sched_debug
initrd /kernel26.img

Insane Debug

The first few debugging examples showed some really nice kernel parameters to turn on really verbose debugging. This kind of debugging is absolutely critical if you want to max out your system or just learn more about what is going on behind the scenes. But there is a final trick that is my favorite, it's the ability to set both environment variables, and more importantly, module parameters at boot.

As an example, here is the boot line that I am using at the moment on an older Dell Desktop, just to illustrate module parameters and environment vars.

title  Arch Linux X-256
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait pause_on_oops=5 panic=60 i915.modeset=1 no_console_suspend ipv6.disable=1 TERM=xterm-256color quiet 5
initrd /kernel26.img

Since it's low on both memory and CPU, I disable ipv6. I also turn on kernel modesetting for the i915 video card, set my terminal to be xterm-256color, and boot straight into X. This lets me use a very optimized arch-linux configuration, amazing how fast thanks to using slim as the login manager, ratpoison as my window manager, and terminal with tmux as my login shell, all from boot, as the pstree shows (plus Synergy!).

init,1
  |-slim,3096
  |   |-X,3098 -nolisten tcp vt07 -auth /var/run/slim.auth
  |   `-ratpoison,3107,askapache
  |       |-terminal,5341 -x sh -c exec /usr/bin/tmux -2 -l -u -q attach -d -t tmux-askapache
  |       |   |-bash,11165
  |       |   |-tmux,5345 -2 -l -u -q attach -d -t tmux-askapache
  |       |   `-{terminal},5346
  |       `-xscreensaver,3113 -no-splash
  |-synergyc,6121,galileo -f --name galileo-fire --restart 10.66.66.2:26666
  |
  `-tmux,5348,askapache -2 -l -u -q attach -d -t tmux-askapache
      |-bash,5351
      |   `-ssh,9969 lug@askapache.com
      `-bash,5868
         `-vim,11149 -p sda1/grub/menu.lst /boot/grub/menu.lst

That kind of optimized system is only possible if you first can figure out your system, by debugging both the kernel as previously illustrated, debugging the init process, and most importantly, by debugging the modules enabled for your system's hardware/firmware/software. Debugging modules is challenging but worth the effort, and then you are able to do some truly insane debugging from grub like the following example, note that the actual grub entry is all on one line, but I split it into 4 lines so you could see it all. This basically turns on every module on this little Dell desktop to be at the absolute max debug level. There is so much logging when I boot this that the system grinds to a halt and is slower than a TI-89 calculator (See Improve Boot Performance).

title  Arch Linux DEBUG INSANE
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait ignore_loglevel debug debug_locks_verbose=1 sched_debug initcall_debug mminit_loglevel=4 udev.log_priority=8
       loglevel=8 earlyprintk=vga,keep log_buf_len=10M print_fatal_signals=1 apm.debug=Y i8042.debug=Y drm.debug=1 scsi_logging_level=1 usbserial.debug=Y
       option.debug=Y pl2303.debug=Y firewire_ohci.debug=1 hid.debug=1 pci_hotplug.debug=Y pci_hotplug.debug_acpi=Y shpchp.shpchp_debug=Y apic=debug
       show_lapic=all hpet=verbose lmb=debug pause_on_oops=5 panic=10 sysrq_always_enabled
initrd /kernel26.img

A couple key items from that grub entry are sysrq_always_enabled which forces on the sysrq magic, which really is a lifesaver when debugging at this level as your machine will freeze/stop-responding sometimes and it's nice to use sysrq to kill all tasks, change the loglevel, unmount all filesystems, or do a hard reboot. Another key parameter is the initcall_debug, which debugs the init process in excruciating detail. Very useful at times. The last parametery I find very useful is the udev.log_priority=8 to turn on udev logging.

Break Into Init

For instance, If you add break=y to your kernel cmdline, init will pause early in the boot process (after loading modules) and launch an interactive sh shell which can be used for troubleshooting purposes. (Normal boot continues after logout.) This is very similar to the shell that shows up if your computer gets turned off before it is able to shutdown properly. But using this parameter lets you enter into this mode differently at will.

title  Arch Linux Init Break
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait break=y
initrd /kernel26.img

Debugging init

This awesome parameter udev.log_priority=8 does the same thing as editing the file /etc/udev/udev.conf except it executes earlier, turning on debugging output for udev. If you want to know your hardware, that is the key parameter right there. Another trick is if you change the /etc/udev/udev.conf to be verbose, then you can make your initrd image include that file to turn on verbose udeb debugging by adding it to your {{Filename|/etc/mkinitcpio.conf} like:

FILES="/etc/modprobe.d/modprobe.conf /etc/udev/udev.conf"

, which on arch is as easy as

# mkinitcpio -p kernel26

Debugging udev is key because the initrd performs a root change at the end of its run to usually launch a program like /sbin/init as part of a chroot, and unless the new file system has a valid /dev directory, udev must be initialized before invoking chroot in order to provide /dev/console.

exec chroot . /sbin/init dev/console 2>&1

So basically, you aren't able to view the logs that are generated before /dev/console is initialized by udev or by a special initrd you compiled yourself. One method the kernel developers use to be able to still get the log messages generated before /dev/console is available is to provide an alternative console that you can enable or disable from grub.

Net Console

If you read through the kernel documentation regarding debugging, you will hear about Netconsole, which can be loaded from the kernel line in GRUB, compiled into your kernel, or loaded at runtime as a module. Having a netconsole entry in your menu.lst is most excellent for debugging slower computers like old laptops or thin-clients. It's easy to use. Just setup a 2nd computer (running arch) to accept syslog requests on a remote port, very fast and quick to do on arch-linux, 1 line to syslog.conf. Then you could use a log-color-parser like ccze to view all syslog logs, or just tail your everything.log. Then on your laptop, boot up and select the netconsole entry from the grub menu, and you will start seeing as much logging as you want on your syslog system. This logging lets you view even earlier log output than is available with the earlyprintk=vga kernel parameter, as netconsole is used by kernel hackers and developers, so it's very powerful.

title  Arch Linux DEBUG Netconsole
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro netconsole=514@10.0.0.2/12:34:56:78:9a:bc debug ignore_loglevel
initrd /kernel26.img

Hijacking cmdline

If you do not have access to GRUB or the kernel boottime cmdline, like on a server or virtual machine, as long as you have root permissions you can still enable this kind of simplistic verbose logging using a neat hack. While you cannot modify the /proc/cmdline even as root, you can place your own cmdline file on top of /proc/cmdline, so that accessing /proc/cmdline actually accesses your file.

For example if I cat /proc/cmdline, I have the following:

root=/dev/disk/by-label/ROOT ro console=tty1 logo.nologo quiet

So I use a simple sed command to replace quiet with verbose like:

sed 's/ quiet/ verbose/' /proc/cmdline > /root/cmdline

Then I bind mount /root/cmdline so that it becomes /proc/cmdline, using the -n option to mount so that this mount won't be recorded in the systems mtab.

mount -n --bind -o ro /root/cmdline /proc/cmdline

Now if I cat /proc/cmdline, I have the following:

root=/dev/disk/by-label/ROOT ro console=tty1 logo.nologo verbose

Advanced Linux Debugging using a Bootloader (GRUB) originally appeared on AskApache.com

HTTP Status Codes and Htaccess ErrorDocuments

AskApache — Tue, 04 Jan 2011 20:56:15 +0000

AskApache.com

I was trying to find an official, authoritative list of HTTP Status Codes but I kept finding lists that weren't authoritative or complete. So I searched and found my answer in the Apache HTTP Server source code. Once I had the exact HTTP Status Codes and resulting Error Documents sent by Apache, I researched deeper into HTTP Status Codes by reading as many related RFC's as I could find, and several other software source codes were explored. This is the most authoritative list I know of, if you can do better leave a comment and I'll update it. Another thing to keep in mind, the Status code number itself is what is used by software and hardware to make determinations, the phrase returned by the status code is for the human only and does not have any weight other than informing the user.. So "503 Service Unavailable", "503 Service Temporarily Unavailable", and "503 Get the heck outta here" are all completely valid.

Update March 9, 2009: A lot of sites on the web have updated their HTTP status code lists to include the HTTP Status codes listed on this page, including Wikipedia, IANA, W3C, and others, so rest assured this info is accurate and complete. If you'd like to see how to create custom error pages for all of these errors like mine /show-error-506 , then check out this detailed tutorial I just posted.

57 APACHE HTTP STATUS RESPONSE CODES

Once I compiled the list of Apache recognized HTTP Status Codes, I was dying to see them all in action (i.e. the corresponding ErrorDocument). At first I thought I would have to create a php or perl script emulating each of the 57 HTTP Status Codes, a tedious undertaking I wasn't about to do. Instead I "asked Apache" by searching the Apache HTTP Documentation for ambiguity sending Status Codes and/or triggering ErrorDocuments with an Apache Directive.
While reading up on mod_alias and the Redirect directive I found:

Apache Docs
Syntax: Redirect [status] URL-path URL The status argument can be used to return other HTTP status codes. Other status codes can be returned by giving the numeric status code as the value of status. If the status is between 300 and 399, the URL argument must be present, otherwise it must be omitted.

100 Continue: ErrorDocument Continue | Sample 100 Continue
This means that the server has received the request headers, and that the client should proceed to send the request body (in case of a request which needs to be sent; for example, a POST request). If the request body is large, sending it to a server when a request has already been rejected based upon inappropriate headers is inefficient. To have a server check if the request could be accepted based on the requests headers alone, a client must send Expect: 100-continue as a header in its initial request (see RFC 2616 14.20 Expect header) and check if a 100 Continue status code is received in response before continuing (or receive 417 Expectation Failed and not continue).
101 Switching Protocols: ErrorDocument Switching Protocols | Sample 101 Switching Protocols
This means the requester has asked the server to switch protocols and the server is acknowledging that it will do so.[3]
102 Processing: ErrorDocument Processing | Sample 102 Processing
(WebDAV) - (RFC 2518 )
200 OK: ErrorDocument OK | Sample 200 OK
Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request the response will contain an entity describing or containing the result of the action.
201 Created: ErrorDocument Created | Sample 201 Created
The request has been fulfilled and resulted in a new resource being created.
202 Accepted: ErrorDocument Accepted | Sample 202 Accepted
The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon, as it might be disallowed when processing actually takes place.
203 Non-Authoritative Information: ErrorDocument Non-Authoritative Information | Sample 203 Non-Authoritative Information
The server successfully processed the request, but is returning information that may be from another source.
204 No Content: ErrorDocument No Content | Sample 204 No Content
The server successfully processed the request, but is not returning any content.
205 Reset Content: ErrorDocument Reset Content | Sample 205 Reset Content
The server successfully processed the request, but is not returning any content. Unlike a 204 response, this response requires that the requester reset the document view.
206 Partial Content: ErrorDocument Partial Content | Sample 206 Partial Content
The server is delivering only part of the resource due to a range header sent by the client. This is used by tools like wget to enable resuming of interrupted downloads, or split a download into multiple simultaneous streams.
207 Multi-Status: ErrorDocument Multi-Status | Sample 207 Multi-Status
(WebDAV) - The message body that follows is an XML message and can contain a number of separate response codes, depending on how many sub-requests were made.
226 IM Used: ErrorDocument IM Used | Sample 226 IM Used
The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance. The actual current instance might not be available except by combining this response with other previous or future responses, as appropriate for the specific instance-manipulation(s).
300 Multiple Choices: ErrorDocument Multiple Choices | Sample 300 Multiple Choices
Indicates multiple options for the resource that the client may follow. It, for instance, could be used to present different format options for video, list files with different extensions, or word sense disambiguation.
301 Moved Permanently: ErrorDocument Moved Permanently | Sample 301 Moved Permanently
This and all future requests should be directed to the given URI.
302 Found: ErrorDocument Found | Sample 302 Found
This is the most popular redirect code[citation needed], but also an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945 ) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented it as a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to disambiguate between the two behaviours. However, the majority of Web applications and frameworks still use the 302 status code as if it were the 303.
303 See Other: ErrorDocument See Other | Sample 303 See Other
The response to the request can be found under another URI using a GET method. When received in response to a PUT, it should be assumed that the server has received the data and the redirect should be issued with a separate GET message.
304 Not Modified: ErrorDocument Not Modified | Sample 304 Not Modified
Indicates the resource has not been modified since last requested. Typically, the HTTP client provides a header like the If-Modified-Since header to provide a time against which to compare. Utilizing this saves bandwidth and reprocessing on both the server and client, as only the header data must be sent and received in comparison to the entirety of the page being re-processed by the server, then resent using more bandwidth of the server and client.
305 Use Proxy: ErrorDocument Use Proxy | Sample 305 Use Proxy
Many HTTP clients (such as Mozilla[4] and Internet Explorer) do not correctly handle responses with this status code, primarily for security reasons.
306 Switch Proxy: ErrorDocument Switch Proxy | Sample 306 Switch Proxy
No longer used.
307 Temporary Redirect: ErrorDocument Temporary Redirect | Sample 307 Temporary Redirect
In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.
400 Bad Request: ErrorDocument Bad Request | Sample 400 Bad Request
The request contains bad syntax or cannot be fulfilled.
401 Unauthorized: ErrorDocument Unauthorized | Sample 401 Unauthorized
Similar to 403 Forbidden, but specifically for use when authentication is possible but has failed or not yet been provided. The response must include a WWW-Authenticate header field containing a challenge applicable to the requested resource. See Basic access authentication and Digest access authentication.
402 Payment Required: ErrorDocument Payment Required | Sample 402 Payment Required
The original intention was that this code might be used as part of some form of digital cash or micropayment scheme, but that has not happened, and this code has never been used.
403 Forbidden: ErrorDocument Forbidden | Sample 403 Forbidden
The request was a legal request, but the server is refusing to respond to it. Unlike a 401 Unauthorized response, authenticating will make no difference.
404 Not Found: ErrorDocument Not Found | Sample 404 Not Found
The requested resource could not be found but may be available again in the future. Subsequent requests by the client are permissible.
405 Method Not Allowed: ErrorDocument Method Not Allowed | Sample 405 Method Not Allowed
A request was made of a resource using a request method not supported by that resource; for example, using GET on a form which requires data to be presented via POST, or using PUT on a read-only resource.
406 Not Acceptable: ErrorDocument Not Acceptable | Sample 406 Not Acceptable
The requested resource is only capable of generating content not acceptable according to the Accept headers sent in the request.
407 Proxy Authentication Required: ErrorDocument Proxy Authentication Required | Sample 407 Proxy Authentication Required
Required
408 Request Timeout: ErrorDocument Request Timeout | Sample 408 Request Timeout
The server timed out waiting for the request.
409 Conflict: ErrorDocument Conflict | Sample 409 Conflict
Indicates that the request could not be processed because of conflict in the request, such as an edit conflict.
410 Gone: ErrorDocument Gone | Sample 410 Gone
Indicates that the resource requested is no longer available and will not be available again. This should be used when a resource has been intentionally removed; however, it is not necessary to return this code and a 404 Not Found can be issued instead. Upon receiving a 410 status code, the client should not request the resource again in the future. Clients such as search engines should remove the resource from their indexes.
411 Length Required: ErrorDocument Length Required | Sample 411 Length Required
The request did not specify the length of its content, which is required by the requested resource.
412 Precondition Failed: ErrorDocument Precondition Failed | Sample 412 Precondition Failed
The server does not meet one of the preconditions that the requester put on the request.
413 Request Entity Too Large: ErrorDocument Request Entity Too Large | Sample 413 Request Entity Too Large
The request is larger than the server is willing or able to process.
414 Request-URI Too Long: ErrorDocument Request-URI Too Long | Sample 414 Request-URI Too Long
The URI provided was too long for the server to process.
415 Unsupported Media Type: ErrorDocument Unsupported Media Type | Sample 415 Unsupported Media Type
The request did not specify any media types that the server or resource supports. For example the client specified that an image resource should be served as image/svg+xml, but the server cannot find a matching version of the image.
416 Requested Range Not Satisfiable: ErrorDocument Requested Range Not Satisfiable | Sample 416 Requested Range Not Satisfiable
The client has asked for a portion of the file, but the server cannot supply that portion (for example, if the client asked for a part of the file that lies beyond the end of the file).
417 Expectation Failed: ErrorDocument Expectation Failed | Sample 417 Expectation Failed
The server cannot meet the requirements of the Expect request-header field.
418 I'm a teapot: ErrorDocument I'm a teapot | Sample 418 I'm a teapot
The HTCPCP server is a teapot. The responding entity MAY be short and stout. Defined by the April Fools specification RFC 2324. See Hyper Text Coffee Pot Control Protocol for more information.
422 Unprocessable Entity: ErrorDocument Unprocessable Entity | Sample 422 Unprocessable Entity
(WebDAV) (RFC 4918 ) - The request was well-formed but was unable to be followed due to semantic errors.
423 Locked: ErrorDocument Locked | Sample 423 Locked
(WebDAV) (RFC 4918 ) - The resource that is being accessed is locked
424 Failed Dependency: ErrorDocument Failed Dependency | Sample 424 Failed Dependency
(WebDAV) (RFC 4918 ) - The request failed due to failure of a previous request (e.g. a PROPPATCH).
425 Unordered Collection: ErrorDocument Unordered Collection | Sample 425 Unordered Collection
Defined in drafts of WebDav Advanced Collections, but not present in "Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol" (RFC 3648).
426 Upgrade Required: ErrorDocument Upgrade Required | Sample 426 Upgrade Required
(RFC 2817 ) - The client should switch to TLS/1.0.
449 Retry With: ErrorDocument Retry With | Sample 449 Retry With
A Microsoft extension. The request should be retried after doing the appropriate action.
500 Internal Server Error: ErrorDocument Internal Server Error | Sample 500 Internal Server Error
A generic error message, given when no more specific message is suitable.
501 Not Implemented: ErrorDocument Not Implemented | Sample 501 Not Implemented
The server either does not recognise the request method, or it lacks the ability to fulfil the request.
502 Bad Gateway: ErrorDocument Bad Gateway | Sample 502 Bad Gateway
The server was acting as a gateway or proxy and received an invalid response from the upstream server.
503 Service Unavailable: ErrorDocument Service Unavailable | Sample 503 Service Unavailable
The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.
504 Gateway Timeout: ErrorDocument Gateway Timeout | Sample 504 Gateway Timeout
The server was acting as a gateway or proxy and did not receive a timely request from the upstream server.
505 HTTP Version Not Supported: ErrorDocument HTTP Version Not Supported | Sample 505 HTTP Version Not Supported
The server does not support the HTTP protocol version used in the request.
506 Variant Also Negotiates: ErrorDocument Variant Also Negotiates | Sample 506 Variant Also Negotiates
(RFC 2295 ) - Transparent content negotiation for the request, results in a circular reference.
507 Insufficient Storage: ErrorDocument Insufficient Storage | Sample 507 Insufficient Storage
(WebDAV) (RFC 4918 )
509 Bandwidth Limit Exceeded: ErrorDocument Bandwidth Limit Exceeded | Sample 509 Bandwidth Limit Exceeded
(Apache bw/limited extension) - This status code, while used by many servers, is not specified in any RFCs.
510 Not Extended: ErrorDocument Not Extended | Sample 510 Not Extended
(RFC 2774 ) - Further extensions to the request are required for the server to fulfil it.

1xx Info / Informational

HTTP_INFO - Request received, continuing process. Indicates a provisional response, consisting only of the Status-Line and optional headers, and is terminated by an empty line.

100 Continue - HTTP_CONTINUE
101 Switching Protocols - HTTP_SWITCHING_PROTOCOLS
102 Processing - HTTP_PROCESSING

2xx Success / OK

HTTP_SUCCESS - The action was successfully received, understood, and accepted. Indicates that the client's request was successfully received, understood, and accepted.

200 OK - HTTP_OK
201 Created - HTTP_CREATED
202 Accepted - HTTP_ACCEPTED
203 Non-Authoritative Information - HTTP_NON_AUTHORITATIVE
204 No Content - HTTP_NO_CONTENT
205 Reset Content - HTTP_RESET_CONTENT
206 Partial Content - HTTP_PARTIAL_CONTENT
207 Multi-Status - HTTP_MULTI_STATUS

3xx Redirect

HTTP_REDIRECT - The client must take additional action to complete the request. Indicates that further action needs to be taken by the user-agent in order to fulfill the request. The action required may be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A user agent should not automatically redirect a request more than 5 times, since such redirections usually indicate an infinite loop.

300 Multiple Choices - HTTP_MULTIPLE_CHOICES
301 Moved Permanently - HTTP_MOVED_PERMANENTLY
302 Found - HTTP_MOVED_TEMPORARILY
303 See Other - HTTP_SEE_OTHER
304 Not Modified - HTTP_NOT_MODIFIED
305 Use Proxy - HTTP_USE_PROXY
306 unused - UNUSED
307 Temporary Redirect - HTTP_TEMPORARY_REDIRECT

4xx Client Error

HTTP_CLIENT_ERROR - The request contains bad syntax or cannot be fulfilled. Indicates case where client seems to have erred. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition.

400 Bad Request - HTTP_BAD_REQUEST
401 Authorization Required - HTTP_UNAUTHORIZED
402 Payment Required - HTTP_PAYMENT_REQUIRED
403 Forbidden - HTTP_FORBIDDEN
404 Not Found - HTTP_NOT_FOUND
405 Method Not Allowed - HTTP_METHOD_NOT_ALLOWED
406 Not Acceptable - HTTP_NOT_ACCEPTABLE
407 Proxy Authentication Required - HTTP_PROXY_AUTHENTICATION_REQUIRED
408 Request Time-out - HTTP_REQUEST_TIME_OUT
409 Conflict - HTTP_CONFLICT
410 Gone - HTTP_GONE
411 Length Required - HTTP_LENGTH_REQUIRED
412 Precondition Failed - HTTP_PRECONDITION_FAILED
413 Request Entity Too Large - HTTP_REQUEST_ENTITY_TOO_LARGE
414 Request-URI Too Large - HTTP_REQUEST_URI_TOO_LARGE
415 Unsupported Media Type - HTTP_UNSUPPORTED_MEDIA_TYPE
416 Requested Range Not Satisfiable - HTTP_RANGE_NOT_SATISFIABLE
417 Expectation Failed - HTTP_EXPECTATION_FAILED
418 I'm a teapot - UNUSED
419 unused - UNUSED
420 unused - UNUSED
421 unused - UNUSED
422 Unprocessable Entity - HTTP_UNPROCESSABLE_ENTITY
423 Locked - HTTP_LOCKED
424 Failed Dependency - HTTP_FAILED_DEPENDENCY
425 No code - HTTP_NO_CODE
426 Upgrade Required - HTTP_UPGRADE_REQUIRED

5xx Server Error

HTTP_SERVER_ERROR - The server failed to fulfill an apparently valid request. Indicate cases in which the server is aware that it has erred or is incapable of performing the request. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. User agents should display any included entity to the user. These response codes are applicable to any request method.

500 Internal Server Error - HTTP_INTERNAL_SERVER_ERROR
501 Method Not Implemented - HTTP_NOT_IMPLEMENTED
502 Bad Gateway - HTTP_BAD_GATEWAY
503 Service Temporarily Unavailable - HTTP_SERVICE_UNAVAILABLE
504 Gateway Time-out - HTTP_GATEWAY_TIME_OUT
505 HTTP Version Not Supported - HTTP_VERSION_NOT_SUPPORTED
506 Variant Also Negotiates - HTTP_VARIANT_ALSO_VARIES
507 Insufficient Storage - HTTP_INSUFFICIENT_STORAGE
508 unused - UNUSED
509 unused - UNUSED
510 Not Extended - HTTP_NOT_EXTENDED

Quick Start to triggering ErrorDocuments for each Status Code

Let start with a quick and easy example. Add the following Redirect rules to your htaccess file, then open your browser and goto each url like yoursite.com/e/400. Don't create an /e/ directory or any files.

Redirect 400 /e/400
Redirect 503 /e/503
Redirect 405 /e/405

Automate the ErrorDocument Triggering

The htaccess Redirects

When a Status code is encountered, Apache outputs the Header and the ErrorDocument for that error code. So you can view any Header and the default ErrorDocument, by causing that numerical error code, which is caused by the Status Code.

For instance, if you request a file that doesn't exist, a 404 Not Found Header is issued and the corresponding ErrorDocument is served with the 404 Not Found Header.

Redirect 100 /e/100
Redirect 101 /e/101
Redirect 102 /e/102
Redirect 200 /e/200
Redirect 201 /e/201
Redirect 202 /e/202
Redirect 203 /e/203
Redirect 204 /e/204
Redirect 205 /e/205
Redirect 206 /e/206
Redirect 207 /e/207
Redirect 300 /e/300 http://www.askapache.com/?s=300
Redirect 301 /e/301 http://www.askapache.com/?s=301
Redirect 302 /e/302 http://www.askapache.com/?s=302
Redirect 303 /e/303 http://www.askapache.com/?s=303
Redirect 304 /e/304 http://www.askapache.com/?s=304
Redirect 305 /e/305 http://www.askapache.com/?s=305
Redirect 306 /e/306 http://www.askapache.com/?s=306
Redirect 307 /e/307 http://www.askapache.com/?s=307
Redirect 400 /e/400
Redirect 401 /e/401
Redirect 402 /e/402
Redirect 403 /e/403
Redirect 404 /e/404
Redirect 405 /e/405
Redirect 406 /e/406
Redirect 407 /e/407
Redirect 408 /e/408
Redirect 409 /e/409
Redirect 410 /e/410
Redirect 411 /e/411
Redirect 412 /e/412
Redirect 413 /e/413
Redirect 414 /e/414
Redirect 415 /e/415
Redirect 416 /e/416
Redirect 417 /e/417
Redirect 418 /e/418
Redirect 419 /e/419
Redirect 420 /e/420
Redirect 421 /e/421
Redirect 422 /e/422
Redirect 423 /e/423
Redirect 424 /e/424
Redirect 425 /e/425
Redirect 426 /e/426
Redirect 500 /e/500
Redirect 501 /e/501
Redirect 502 /e/502
Redirect 503 /e/503
Redirect 504 /e/504
Redirect 505 /e/505
Redirect 506 /e/506
Redirect 507 /e/507
Redirect 508 /e/508
Redirect 509 /e/509
Redirect 510 /e/510

PHP script that gets and outputs the Headers/Content

Now all I have to do is add 57 Redirect Directives to my htaccess, and then request each of them 1 at a time from my browser to see the result, and use a packet sniffing program like WireShark to see the Headers. Uh, scratch that, that would take way too long!

Instead I hacked up a simple php script using cURL to automate sending GET Requests to each of the 57 Redirect URL-paths. A side benefit of using the php script is that it performs all 57 Requests concurrently and saves each Requests returned headers and content to an output buffer. After all 57 have been queried, the output buffer is flushed to the browser.

 $res)
{
foreach($res as $key)
{
$ch = curl_init("$SITENAME/e/$key");
$fp = fopen ($TMPSAVETO, "a");
curl_setopt ($ch, CURLOPT_FILE, $fp);
curl_setopt ($ch, CURLOPT_FOLLOWLOCATION ,1);
curl_setopt ($ch, CURLOPT_HEADER ,1);
curl_exec ($ch);
curl_close ($ch);
fclose ($fp);
}
}
$OUT='';
ob_start();
header ("Content-Type: text/plain;");
readfile($TMPSAVETO);
$OUT=ob_get_clean();
echo $OUT;
unlink($TMPSAVETO);
exit;
?>

Headers and Content Returned

100 Continue

HTTP/1.1 100 Continue 100 Continue

Continue

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

101 Switching Protocols

HTTP/1.1 101 Switching Protocols 101 Switching Protocols

Switching Protocols

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

102 Processing

HTTP/1.1 102 Processing X-Pad: avoid browser bug 102 Processing

Processing

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

200 OK

HTTP/1.1 200 OK 200 OK

OK

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

201 Created

HTTP/1.1 201 Created 201 Created

Created

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

202 Accepted

HTTP/1.1 202 Accepted 202 Accepted

Accepted

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

203 Non-Authoritative Information

HTTP/1.1 203 Non-Authoritative Information 203 Non-Authoritative Information

Non-Authoritative Information

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

204 No Content

HTTP/1.1 204 No Content
Content-Type: text/plain; charset=UTF-8

205 Reset Content

HTTP/1.1 205 Reset Content 205 Reset Content

Reset Content

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

206 Partial Content

HTTP/1.1 206 Partial Content 206 Partial Content

Partial Content

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

207 Multi-Status

HTTP/1.1 207 Multi-Status X-Pad: avoid browser bug 207 Multi-Status

Multi-Status

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

300 Multiple Choices

HTTP/1.1 300 Multiple Choices
Location: http://www.askapache.com/?s=300

300 Multiple Choices


Multiple Choices

301 Moved Permanently

HTTP/1.1 301 Moved Permanently Location: http://www.askapache.com/?s=301 301 Moved Permanently

Moved Permanently

The document has moved here .

302 Found

HTTP/1.1 302 Found Location: http://www.askapache.com/?s=302 302 Found

Found

The document has moved here .

303 See Other

HTTP/1.1 303 See Other Location: http://www.askapache.com/?s=303 303 See Other

See Other

The answer to your request is located here .

304 Not Modified

HTTP/1.1 304 Not Modified

305 Use Proxy

HTTP/1.1 305 Use Proxy Location: http://www.askapache.com/?s=305 305 Use Proxy

Use Proxy

This resource is only accessible through the proxy http://www.askapache.com/?s=305
You will need to configure your client to use that proxy.

306 unused

HTTP/1.1 306 unused Location: http://www.askapache.com/?s=306 306 unused

unused

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

307 Temporary Redirect

HTTP/1.1 307 Temporary Redirect Location: http://www.askapache.com/?s=307 307 Temporary Redirect

Temporary Redirect

The document has moved here .

400 Bad Request

HTTP/1.1 400 Bad Request Connection: close 400 Bad Request

Bad Request

Your browser sent a request that this server could not understand.

401 Authorization Required

HTTP/1.1 401 Authorization Required 401 Authorization Required

Authorization Required

This server could not verify that you are authorized to access the document requested. Either you supplied the wrong credentials (e.g., bad password), or your browser doesn't understand how to supply the credentials required.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

402 Payment Required

HTTP/1.1 402 Payment Required 402 Payment Required

Payment Required

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

403 Forbidden

HTTP/1.1 403 Forbidden 403 Forbidden

Forbidden

You don't have permission to access /e/403 on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

404 Not Found

HTTP/1.1 404 Not Found 404 Not Found

Not Found

The requested URL /e/404 was not found on this server.

NOTE:
You will most definately want to check out and use the Google 404 Error Page if you run WordPress.

405 Method Not Allowed

HTTP/1.1 405 Method Not Allowed Allow: TRACE 405 Method Not Allowed

Method Not Allowed

The requested method GET is not allowed for the URL /e/405.

406 Not Acceptable

HTTP/1.1 406 Not Acceptable 406 Not Acceptable

Not Acceptable

An appropriate representation of the requested resource /e/406 could not be found on this server.

407 Proxy Authentication Required

HTTP/1.1 407 Proxy Authentication Required 407 Proxy Authentication Required

Proxy Authentication Required

408 Request Time-out

HTTP/1.1 408 Request Time-out Connection: close 408 Request Time-out

Request Time-out

Server timeout waiting for the HTTP request from the client.

409 Conflict

HTTP/1.1 409 Conflict 409 Conflict

Conflict

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

410 Gone

HTTP/1.1 410 Gone 410 Gone

Gone

The requested resource
/e/410
is no longer available on this server and there is no forwarding address. Please remove all references to this resource.

411 Length Required

HTTP/1.1 411 Length Required Connection: close 411 Length Required

Length Required

A request of the requested method GET requires a valid Content-length.

412 Precondition Failed

HTTP/1.1 412 Precondition Failed 412 Precondition Failed

Precondition Failed

The precondition on the request for the URL /e/412 evaluated to false.

413 Request Entity Too Large

HTTP/1.1 413 Request Entity Too Large
Connection: close

413 Request Entity Too Large


Request Entity Too Large
The requested resource
/e/413
does not allow request data with GET requests, or the amount of data provided in
the request exceeds the capacity limit.

414 Request-URI Too Large

HTTP/1.1 414 Request-URI Too Large Connection: close 414 Request-URI Too Large

Request-URI Too Large

The requested URL's length exceeds the capacity limit for this server.

415 Unsupported Media Type

HTTP/1.1 415 Unsupported Media Type 415 Unsupported Media Type

Unsupported Media Type

The supplied request data is not in a format acceptable for processing by this resource.

416 Requested Range Not Satisfiable

HTTP/1.1 416 Requested Range Not Satisfiable

417 Expectation Failed

HTTP/1.1 417 Expectation Failed 417 Expectation Failed

Expectation Failed

The expectation given in the Expect request-header field could not be met by this server.

The client sent

Expect:

418 I'm a teapot

HTTP/1.1 418 I'm a teapot 418 I'm a teapot

I'm a teapot

Unfortunately this coffee machine is out of coffee.

419 unused

HTTP/1.1 419 unused 419 unused

unused

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

420 unused

HTTP/1.1 420 unused 420 unused

unused

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

421 unused

HTTP/1.1 421 unused 421 unused

unused

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

422 Unprocessable Entity

HTTP/1.1 422 Unprocessable Entity 422 Unprocessable Entity

Unprocessable Entity

The server understands the media type of the request entity, but was unable to process the contained instructions.

423 Locked

HTTP/1.1 423 Locked 423 Locked

Locked

The requested resource is currently locked. The lock must be released or proper identification given before the method can be applied.

424 Failed Dependency

HTTP/1.1 424 Failed Dependency 424 Failed Dependency

Failed Dependency

The method could not be performed on the resource because the requested action depended on another action and that other action failed.

425 No code

HTTP/1.1 425 No code 425 No code

No code

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

426 Upgrade Required

HTTP/1.1 426 Upgrade Required 426 Upgrade Required

Upgrade Required

The requested resource can only be retrieved using SSL. The server is willing to upgrade the current connection to SSL, but your client doesn't support it. Either upgrade your client, or try requesting the page using https://

500 Internal Server Error

HTTP/1.1 500 Internal Server Error Connection: close 500 Internal Server Error

Internal Server Error

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

501 Method Not Implemented

HTTP/1.1 501 Method Not Implemented Allow: TRACE Connection: close 501 Method Not Implemented

Method Not Implemented

GET to /e/501 not supported.

502 Bad Gateway

HTTP/1.1 502 Bad Gateway X-Pad: avoid browser bug 502 Bad Gateway

Bad Gateway

The proxy server received an invalid response from an upstream server.

503 Service Temporarily Unavailable

HTTP/1.1 503 Service Temporarily Unavailable Connection: close 503 Service Temporarily Unavailable

Service Temporarily Unavailable

The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

504 Gateway Time-out

HTTP/1.1 504 Gateway Time-out 504 Gateway Time-out

Gateway Time-out

The proxy server did not receive a timely response from the upstream server.

505 HTTP Version Not Supported

HTTP/1.1 505 HTTP Version Not Supported 505 HTTP Version Not Supported

HTTP Version Not Supported

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

506 Variant Also Negotiates

HTTP/1.1 506 Variant Also Negotiates 506 Variant Also Negotiates

Variant Also Negotiates

A variant for the requested resource

    /e/506

is itself a negotiable resource. This indicates a configuration error.

507 Insufficient Storage

HTTP/1.1 507 Insufficient Storage 507 Insufficient Storage

Insufficient Storage

The method could not be performed on the resource because the server is unable to store the representation needed to successfully complete the request. There is insufficient free space left in your storage allocation.

508 unused

HTTP/1.1 508 unused 508 unused

unused

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

509 unused

HTTP/1.1 509 unused 509 unused

unused

The server encountered an internal error or misconfigurationand was unable to complete your request.

Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

510 Not Extended

HTTP/1.1 510 Not Extended X-Pad: avoid browser bug 510 Not Extended

Not Extended

A mandatory extension policy in the request is not accepted by the server for this resource.

Apache Source Code

httpd.h

From httpd.h

/**
* The size of the static array in http_protocol.c for storing
* all of the potential response status-lines (a sparse table).
* A future version should dynamically generate the apr_table_t at startup.
*/
#define RESPONSE_CODES 57
#define HTTP_CONTINUE            100
#define HTTP_SWITCHING_PROTOCOLS       101
#define HTTP_PROCESSING          102
#define HTTP_OK              200
#define HTTP_CREATED             201
#define HTTP_ACCEPTED            202
#define HTTP_NON_AUTHORITATIVE       203
#define HTTP_NO_CONTENT          204
#define HTTP_RESET_CONTENT         205
#define HTTP_PARTIAL_CONTENT         206
#define HTTP_MULTI_STATUS          207
#define HTTP_MULTIPLE_CHOICES        300
#define HTTP_MOVED_PERMANENTLY       301
 
#define HTTP_MOVED_TEMPORARILY       302
#define HTTP_SEE_OTHER           303
#define HTTP_NOT_MODIFIED          304
#define HTTP_USE_PROXY           305
#define HTTP_TEMPORARY_REDIRECT      307
#define HTTP_BAD_REQUEST           400
#define HTTP_UNAUTHORIZED          401
#define HTTP_PAYMENT_REQUIRED        402
#define HTTP_FORBIDDEN           403
#define HTTP_NOT_FOUND           404
#define HTTP_METHOD_NOT_ALLOWED      405
#define HTTP_NOT_ACCEPTABLE        406
#define HTTP_PROXY_AUTHENTICATION_REQUIRED 407
#define HTTP_REQUEST_TIME_OUT        408
#define HTTP_CONFLICT            409
#define HTTP_GONE              410
#define HTTP_LENGTH_REQUIRED         411
#define HTTP_PRECONDITION_FAILED       412
#define HTTP_REQUEST_ENTITY_TOO_LARGE    413
#define HTTP_REQUEST_URI_TOO_LARGE     414
#define HTTP_UNSUPPORTED_MEDIA_TYPE    415
#define HTTP_RANGE_NOT_SATISFIABLE     416
#define HTTP_EXPECTATION_FAILED      417
#define HTTP_UNPROCESSABLE_ENTITY      422
#define HTTP_LOCKED            423
#define HTTP_FAILED_DEPENDENCY       424
#define HTTP_UPGRADE_REQUIRED        426
#define HTTP_INTERNAL_SERVER_ERROR     500
#define HTTP_NOT_IMPLEMENTED         501
#define HTTP_BAD_GATEWAY           502
#define HTTP_SERVICE_UNAVAILABLE       503
#define HTTP_GATEWAY_TIME_OUT        504
#define HTTP_VERSION_NOT_SUPPORTED     505
#define HTTP_VARIANT_ALSO_VARIES       506
#define HTTP_INSUFFICIENT_STORAGE      507
#define HTTP_NOT_EXTENDED          510
 
/** is the status code informational */
#define ap_is_HTTP_INFO(x)     (((x) >= 100)&&((x) < 200))
/** is the status code OK ?*/
#define ap_is_HTTP_SUCCESS(x)    (((x) >= 200)&&((x) < 300))
/** is the status code a redirect */
#define ap_is_HTTP_REDIRECT(x)   (((x) >= 300)&&((x) < 400))
/** is the status code a error (client or server) */
#define ap_is_HTTP_ERROR(x)    (((x) >= 400)&&((x) < 600))
/** is the status code a client error  */
#define ap_is_HTTP_CLIENT_ERROR(x) (((x) >= 400)&&((x) < 500))
/** is the status code a server error  */
#define ap_is_HTTP_SERVER_ERROR(x) (((x) >= 500)&&((x) < 600))
/** is the status code a (potentially) valid response code?  */
#define ap_is_HTTP_VALID_RESPONSE(x) (((x) >= 100)&&((x) < 600))
 
/** should the status code drop the connection */
#define ap_status_drops_connection(x) \
(((x) == HTTP_BAD_REQUEST)       || \
((x) == HTTP_REQUEST_TIME_OUT)    || \
((x) == HTTP_LENGTH_REQUIRED)     || \
((x) == HTTP_REQUEST_ENTITY_TOO_LARGE) || \
((x) == HTTP_REQUEST_URI_TOO_LARGE) || \
((x) == HTTP_INTERNAL_SERVER_ERROR) || \
((x) == HTTP_SERVICE_UNAVAILABLE) || \
((x) == HTTP_NOT_IMPLEMENTED))

HTTP_INFO

Is the status code (x) informational?

x >= 100 && x < 200

HTTP_SUCCESS

Is the status code (x) OK?

x >= 200 && x < 300

HTTP_REDIRECT

Is the status code (x) a redirect?

x >= 300 && x < 400

HTTP_ERROR

Is the status code (x) a error (client or server)?

x >= 400 && x < 600

HTTP_CLIENT_ERROR

Is the status code (x) a client error?

x >= 400 && x < 500

HTTP_SERVER_ERROR

Is the status code (x) a server error?

x >= 500 && x < 600

HTTP_VALID_RESPONSE

Is the status code (x) a (potentially) valid response code?

x >= 100 && x < 600

http_protocol.c

From http_protocol.c

static const char * status_lines[RESPONSE_CODES] =
static const char * const status_lines[RESPONSE_CODES] =
"100 Continue",
"101 Switching Protocols",
"102 Processing",
"200 OK",
"201 Created",
"202 Accepted",
"203 Non-Authoritative Information",
"204 No Content",
"205 Reset Content",
"206 Partial Content",
"207 Multi-Status",
"300 Multiple Choices",
"301 Moved Permanently",
"302 Found",
"303 See Other",
"304 Not Modified",
"305 Use Proxy",
"306 unused",
"307 Temporary Redirect",
"400 Bad Request",
"401 Authorization Required",
"402 Payment Required",
"403 Forbidden",
"404 Not Found",
"405 Method Not Allowed",
"406 Not Acceptable",
"407 Proxy Authentication Required",
"408 Request Time-out",
"409 Conflict",
"410 Gone",
"411 Length Required",
"412 Precondition Failed",
"413 Request Entity Too Large",
"414 Request-URI Too Large",
"415 Unsupported Media Type",
"416 Requested Range Not Satisfiable",
"417 Expectation Failed",
"418 unused",
"419 unused",
"420 unused",
"421 unused",
"422 Unprocessable Entity",
"423 Locked",
"424 Failed Dependency",
"425 No code",
"426 Upgrade Required",
"500 Internal Server Error",
"501 Method Not Implemented",
"502 Bad Gateway",
"503 Service Temporarily Unavailable",
"504 Gateway Time-out",
"505 HTTP Version Not Supported",
"506 Variant Also Negotiates",
"507 Insufficient Storage",
"508 unused",
"509 unused",
"510 Not Extended"

IANA HTTP Status Code Registry

Value	Description	Reference
100	Continue	[RFC2616] , Section 10.1.1
101	Switching Protocols	[RFC2616] , Section 10.1.2
102	Processing	[RFC2518] , Section 10.1
200	OK	[RFC2616] , Section 10.2.1
201	Created	[RFC2616] , Section 10.2.2
202	Accepted	[RFC2616] , Section 10.2.3
203	Non-Authoritative Information	[RFC2616] , Section 10.2.4
204	No Content	[RFC2616] , Section 10.2.5
205	Reset Content	[RFC2616] , Section 10.2.6
206	Partial Content	[RFC2616] , Section 10.2.7
207	Multi-Status	[RFC4918] , Section 11.1
226	IM Used	[RFC3229] , Section 10.4.1
300	Multiple Choices	[RFC2616] , Section 10.3.1
301	Moved Permanently	[RFC2616] , Section 10.3.2
302	Found	[RFC2616] , Section 10.3.3
303	See Other	[RFC2616] , Section 10.3.4
304	Not Modified	[RFC2616] , Section 10.3.5
305	Use Proxy	[RFC2616] , Section 10.3.6
306	(Reserved)	[RFC2616] , Section 10.3.7
307	Temporary Redirect	[RFC2616] , Section 10.3.8
400	Bad Request	[RFC2616] , Section 10.4.1
401	Unauthorized	[RFC2616] , Section 10.4.2
402	Payment Required	[RFC2616] , Section 10.4.3
403	Forbidden	[RFC2616] , Section 10.4.4
404	Not Found	[RFC2616] , Section 10.4.5
405	Method Not Allowed	[RFC2616] , Section 10.4.6
406	Not Acceptable	[RFC2616] , Section 10.4.7
407	Proxy Authentication Required	[RFC2616] , Section 10.4.8
408	Request Timeout	[RFC2616] , Section 10.4.9
409	Conflict	[RFC2616] , Section 10.4.10
410	Gone	[RFC2616] , Section 10.4.11
411	Length Required	[RFC2616] , Section 10.4.12
412	Precondition Failed	[RFC2616] , Section 10.4.13
413	Request Entity Too Large	[RFC2616] , Section 10.4.14
414	Request-URI Too Long	[RFC2616] , Section 10.4.15
415	Unsupported Media Type	[RFC2616] , Section 10.4.16
416	Requested Range Not Satisfiable	[RFC2616] , Section 10.4.17
417	Expectation Failed	[RFC2616] , Section 10.4.18
422	Unprocessable Entity	[RFC4918] , Section 11.2
423	Locked	[RFC4918] , Section 11.3
424	Failed Dependency	[RFC4918] , Section 11.4
426	Upgrade Required	[RFC2817] , Section 6
500	Internal Server Error	[RFC2616] , Section 10.5.1
501	Not Implemented	[RFC2616] , Section 10.5.2
502	Bad Gateway	[RFC2616] , Section 10.5.3
503	Service Unavailable	[RFC2616] , Section 10.5.4
504	Gateway Timeout	[RFC2616] , Section 10.5.5
505	HTTP Version Not Supported	[RFC2616] , Section 10.5.6
506	Variant Also Negotiates	[RFC2295] , Section 8.1
507	Insufficient Storage	[RFC4918] , Section 11.5
510	Not Extended	[RFC2774] , Section 7

WordPress 2.8 Changes

I just learned that my modification to the WordPress core was accepted and will be implemented for version 2.8! This may mean WordPress is the only 100% HTTP/1.1 compliant software on the net! Below is the new list (I thought someone out there could use the php array) and as you can see, unfortunately418 I'm a teapotdidn't make it ;)

$wp_header_to_desc = array(
  100 => 'Continue',
  101 => 'Switching Protocols',
  102 => 'Processing',
 
  200 => 'OK',
  201 => 'Created',
  202 => 'Accepted',
  203 => 'Non-Authoritative Information',
  204 => 'No Content',
  205 => 'Reset Content',
  206 => 'Partial Content',
  207 => 'Multi-Status',
  226 => 'IM Used',
 
  300 => 'Multiple Choices',
  301 => 'Moved Permanently',
  302 => 'Found',
  303 => 'See Other',
  304 => 'Not Modified',
  305 => 'Use Proxy',
  306 => 'Reserved',
  307 => 'Temporary Redirect',
 
  400 => 'Bad Request',
  401 => 'Unauthorized',
  402 => 'Payment Required',
  403 => 'Forbidden',
  404 => 'Not Found',
  405 => 'Method Not Allowed',
  406 => 'Not Acceptable',
  407 => 'Proxy Authentication Required',
  408 => 'Request Timeout',
  409 => 'Conflict',
  410 => 'Gone',
  411 => 'Length Required',
  412 => 'Precondition Failed',
  413 => 'Request Entity Too Large',
  414 => 'Request-URI Too Long',
  415 => 'Unsupported Media Type',
  416 => 'Requested Range Not Satisfiable',
  417 => 'Expectation Failed',
  422 => 'Unprocessable Entity',
  423 => 'Locked',
  424 => 'Failed Dependency',
  426 => 'Upgrade Required',
 
  500 => 'Internal Server Error',
  501 => 'Not Implemented',
  502 => 'Bad Gateway',
  503 => 'Service Unavailable',
  504 => 'Gateway Timeout',
  505 => 'HTTP Version Not Supported',
  506 => 'Variant Also Negotiates',
  507 => 'Insufficient Storage',
  510 => 'Not Extended'
);

RIPE WHOIS

All the status codes are standard HTTP codes ( http://www.iana.org/assignments/http-status-codes ).

Clients should avoid any form of coupling with the the text/plain error message contained in response body since it may change between different releases of the API and is only intended as a starting point for indentifying the real causes of the exception event.

The following table gives a brief description of the mapping between standard Whois V.3 responses and the related REST services status codes. Consider this table as just an example of the error mapping strategy, it may change with future releases.

System Exception	Whois Error	HTTP Status Code
IllegalArgumentException		Bad Request (400)
IllegalStateException		Internal Server Error (500)
UnsupportedOperationException		Bad Request (400)
ObjectNotFoundException		Not Found (404)
IllegalStateException		Bad Request (400)
IOException		Bad Request (400)
SystemException		Internal Server Error (500)
TooManyResultsException		Internal Server Error (500)
WhoisServerException	No Entries Found (101)	Not Found (404)
WhoisServerException	Unknown Source (102)	Bad Request (400)
WhoisServerException	Unknown Object Type (103)	Bad Request (400)
WhoisServerException	Unknown Attribute in Query (104)	Bad Request (400)
WhoisServerException	Attribute Is Not Inverse Searchable (105)	Bad Request (400)
WhoisServerException	No Search Key Specified (106)	Bad Request (400)
WhoisServerException	Access Denied (201)	Forbidden (403)
WhoisServerException	Access Control Limit Reached (202)	Forbidden (403)
WhoisServerException	Address Passing Not Allowed (203)	Bad Request (400)
WhoisServerException	Maximum Referral Lines Exceeded (204)	Internal Server Error (500)
WhoisServerException	Connection Has Been Closed(301)	Internal Server Error (500)
WhoisServerException	Referral Timeout (302)	Internal Server Error (500)
WhoisServerException	No Referral Host (303)	Internal Server Error (500)
WhoisServerException	Referral Host Not Responding (304)	Internal Server Error (500)

Clients will have to define error messages generic enough to represent the four main error conditions, that are Bad Request, Forbidden, Not Found and Internal Server Error.

For example a possible mapping for client side error messages may be:

HTTP Status Code	Error Message
Bad Request (400)	The service is unable to understand and process the query.
Forbidden (403)	Query limit exceeded.
Not Found (404)	No results were found for Your search "`Search term`"
Internal Server Error (500)	The server encountered an unexpected condition which prevented it from fulfilling the request.

Helpful HTTP Links

IANA registry
Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)
Adobe Flash status code definitions (ie 408)
Microsoft Internet Information Server Status Codes and Sub-Codes
httplint
HTTP Headers, brief intro.
Common User-Agent Issues
[RFC2295] Holtman, K. and A.H. Mutz , " Transparent Content Negotiation in HTTP ", RFC 2295, March 1998.
[RFC2518] Goland, Y. , Whitehead, E. , Faizi, A. , Carter, S.R. , and D. Jensen , " HTTP Extensions for Distributed Authoring -- WEBDAV ", RFC 2518, February 1999.
[RFC2616] Fielding, R. , Gettys, J. , Mogul, J. , Frystyk, H. , Masinter, L. , Leach, P. , and T. Berners-Lee , " Hypertext Transfer Protocol -- HTTP/1.1 ", RFC 2616, June 1999.
[RFC2774] Nielsen, H. , Leach, P. , and S. Lawrence , " An HTTP Extension Framework ", RFC 2774, February 2000.
[RFC2817] Khare, R. and S. Lawrence, " Upgrading to TLS Within HTTP/1.1 ", RFC 2817, May 2000.
[RFC3229] Mogul, J., Krishnamurthy, B., Douglis, F., Feldmann, A., Goland, Y., van Hoff, A., and D. Hellerstein, " Delta encoding in HTTP ", RFC 3229, January 2002.
[RFC4918] Dusseault, L., Ed. , " HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) ", RFC 4918, June 2007.

HTTP Status Codes and Htaccess ErrorDocuments originally appeared on AskApache.com

PHP to handle HTTP Status Codes for ErrorDocument

AskApache — Fri, 19 Nov 2010 04:03:22 +0000

AskApache.com

The php part of this article is based on my Advanced WordPress 404.php article from 2008. Many of the following ideas came out of the research performed to enumerate every single Apache ErrorDocument, including learning how to view the defaults and many cool tricks for htaccess.

The PHP HTTP ErrorDocument Handler

Just save this as /err.php or whatever. The best is to put it in a cgi-bin script-alias directory under your DOCUMENT_ROOT like /cgi-bin/e.php but most people don't know how. That way you can setup some advanced stuff in a /cgi-bin/.htaccess file. If you are interested in locking it down, I recommend reading Securing php.ini and php-cgi with .htaccess.

Advantages and Reasons for Using

Fast, HTTP Protocol Compliance, protection. If you are reading this article, you already know and just want to check out the code!

 'Continue',
  101 => 'Switching Protocols',
  102 => 'Processing',
  200 => 'OK',
  201 => 'Created',
  202 => 'Accepted',
  203 => 'Non-Authoritative Information',
  204 => 'No Content',
  205 => 'Reset Content',
  206 => 'Partial Content',
  207 => 'Multi-Status',
  226 => 'IM Used',
  300 => 'Multiple Choices',
  301 => 'Moved Permanently',
  302 => 'Found',
  303 => 'See Other',
  304 => 'Not Modified',
  305 => 'Use Proxy',
  306 => 'Reserved',
  307 => 'Temporary Redirect',
  400 => 'Bad Request',
  401 => 'Unauthorized',
  402 => 'Payment Required',
  403 => 'Forbidden',
  404 => 'Not Found',
  405 => 'Method Not Allowed',
  406 => 'Not Acceptable',
  407 => 'Proxy Authentication Required',
  408 => 'Request Timeout',
  409 => 'Conflict',
  410 => 'Gone',
  411 => 'Length Required',
  412 => 'Precondition Failed',
  413 => 'Request Entity Too Large',
  414 => 'Request-URI Too Long',
  415 => 'Unsupported Media Type',
  416 => 'Requested Range Not Satisfiable',
  417 => 'Expectation Failed',
  422 => 'Unprocessable Entity',
  423 => 'Locked',
  424 => 'Failed Dependency',
  426 => 'Upgrade Required',
  500 => 'Internal Server Error',
  501 => 'Not Implemented',
  502 => 'Bad Gateway',
  503 => 'Service Unavailable',
  504 => 'Gateway Timeout',
  505 => 'HTTP Version Not Supported',
  506 => 'Variant Also Negotiates',
  507 => 'Insufficient Storage',
  510 => 'Not Extended'
  );
 
  $status_msg = array(
  400 => "Your browser sent a request that this server could not understand.",
  401 => "This server could not verify that you are authorized to access the document requested.",
  402 => 'The server encountered an internal error or misconfiguration and was unable to complete your request.',
  403 => "You don't have permission to access %U% on this server.",
  404 => "We couldn't find that uri on our server, though it's most certainly not your fault.",
  405 => "The requested method is not allowed for the URL %U%.",
  406 => "An appropriate representation of the requested resource %U% could not be found on this server.",
  407 => "An appropriate representation of the requested resource %U% could not be found on this server.",
  408 => "Server timeout waiting for the HTTP request from the client.",
  409 => 'The server encountered an internal error or misconfiguration and was unable to complete your request.',
  410 => "The requested resource %U% is no longer available on this server and there is no forwarding address. Please remove all references to this resource.",
  411 => "A request of the requested method GET requires a valid Content-length.",
  412 => "The precondition on the request for the URL %U% evaluated to false.",
  413 => "The requested resource %U% does not allow request data with GET requests, or the amount of data provided in the request exceeds the capacity limit.",
  414 => "The requested URL's length exceeds the capacity limit for this server.",
  415 => "The supplied request data is not in a format acceptable for processing by this resource.",
  416 => 'Requested Range Not Satisfiable',
  417 => "The expectation given in the Expect request-header field could not be met by this server. The client sent Expect:",
  422 => "The server understands the media type of the request entity, but was unable to process the contained instructions.",
  423 => "The requested resource is currently locked. The lock must be released or proper identification given before the method can be applied.",
  424 => "The method could not be performed on the resource because the requested action depended on another action and that other action failed.",
  425 => 'The server encountered an internal error or misconfiguration and was unable to complete your request.',
  426 => "The requested resource can only be retrieved using SSL. Either upgrade your client, or try requesting the page using https://",
  500 => 'The server encountered an internal error or misconfiguration and was unable to complete your request.',
  501 => "This type of request method to %U% is not supported.",
  502 => "The proxy server received an invalid response from an upstream server.",
  503 => "The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.",
  504 => "The proxy server did not receive a timely response from the upstream server.",
  505 => 'The server encountered an internal error or misconfiguration and was unable to complete your request.',
  506 => "A variant for the requested resource %U% is itself a negotiable resource. This indicates a configuration error.",
  507 => "The method could not be performed.  There is insufficient free space left in your storage allocation.",
  510 => "A mandatory extension policy in the request is not accepted by the server for this resource."
  );
 
  // Get the Status Code
  if (isset($_SERVER['REDIRECT_STATUS']) && ($_SERVER['REDIRECT_STATUS'] != 200))$sc = $_SERVER['REDIRECT_STATUS'];
  elseif (isset($_SERVER['REDIRECT_REDIRECT_STATUS']) && ($_SERVER['REDIRECT_REDIRECT_STATUS'] != 200)) $sc = $_SERVER['REDIRECT_REDIRECT_STATUS'];
  $sc = (!isset($_GET['error']) ? 404 : $_GET['error']);
 
  $sc=abs(intval($sc));
 
  // Redirect to server home if called directly or if status is under 400
  if( ( (isset($_SERVER['REDIRECT_STATUS']) && $_SERVER['REDIRECT_STATUS'] == 200) && (floor($sc / 100) == 3) )
     || (!isset($_GET['error']) && $_SERVER['REDIRECT_STATUS'] == 200)  )
  {
      @header("Location: http://{$_SERVER['SERVER_NAME']}",1,302);
      die();
  }
 
  // Check range of code or issue 500
  if (($sc < 200) || ($sc > 599)) $sc = 500;
 
  // Check for valid protocols or else issue 505
  if (!in_array($_SERVER["SERVER_PROTOCOL"], array('HTTP/1.0','HTTP/1.1','HTTP/0.9'))) $sc = 505;
 
  // Get the status reason
  $reason = (isset($status_reason[$sc]) ? $status_reason[$sc] : '');
 
  // Get the status message
  $msg = (isset($status_msg[$sc]) ? str_replace('%U%', htmlspecialchars(strip_tags(stripslashes($_SERVER['REQUEST_URI']))), $status_msg[$sc]) : 'Error');
 
  // issue optimized headers (optimized for your server)
  @header("{$_SERVER['SERVER_PROTOCOL']} {$sc} {$reason}", 1, $sc);
  if( @php_sapi_name() != 'cgi-fcgi' ) @header("Status: {$sc} {$reason}", 1, $sc);
 
  // A very small footprint for certain types of 4xx class errors and all 5xx class errors
  if (in_array($sc, array(400, 403, 405)) || (floor($sc / 100) == 5))
  {
    @header("Connection: close", 1);
    if ($sc == 405) @header('Allow: GET,HEAD,POST,OPTIONS', 1, 405);
  }
 
  echo "\n";
  echo "\n{$sc} {$reason}\n{$reason}
\n{$msg}
\n\n";
}
 
function askapache_global_debug()
{
  # http://www.php.net/manual/en/function.array-walk.php#100681
  global $_GET,$_POST,$_ENV,$_SERVER;  $g=array('_ENV','_SERVER','_GET','_POST');
  array_walk_recursive($g, create_function('$n','global $$n;if( !!$$n&&ob_start()&&(print "[ $"."$n ]\n")&&array_walk($$n,
    create_function(\'$v,$k\', \'echo "[$k] => $v\n";\'))) echo "<"."p"."r"."e>".htmlspecialchars(ob_get_clean())."<"."/"."pr"."e>";') );
}
 
print_error_page();
//if($_SERVER['REMOTE_ADDR']=='youripaddress')askapache_global_debug();
echo "\n";
echo ob_get_clean();
exit;
?>

Note: If you are installing this on a non-linux/non-apache machine/server, you will need to read your products documentation for custom error documents. It will work on any machine that can run php.

Htaccess ErrorDocument Tips

The thing is, how do you setup your website to use this php file to be able to handle all those HTTP Status Codes gracefully? You just need to configure your server to use that php file for any Status Codes you want. If you are building an ErrorDocument handling system for a server-wide, multi-site, setup, you will want to instead use the method I use. Instead of using a separate language like PHP, Python, Ruby, Perl, etc, to handle errors, I rely on the very safe and fast SSI method. I detailed the advanced ErrorDocument SSI (.htaccess or httpd.conf)..

If you instead like most of us, you will be setting this up for 1 site, or 1 DOCUMENT_ROOT serving virtual hosts. For that the best method is to modify your .htaccess file.

Using Redirect in .htaccess to trigger Errors

This is one of my all time favorite discoveries from my apache studies. It's documented elsewhere on this site, but if you want to test it out, just request www.askapache.com/show-error-402. Of course the error handling that I have in place is quite nice.

Redirect 400 /show-error-400
Redirect 401 /show-error-401
Redirect 402 /show-error-402
Redirect 403 /show-error-403
Redirect 405 /show-error-405
Redirect 406 /show-error-406
Redirect 407 /show-error-407
Redirect 408 /show-error-408
Redirect 409 /show-error-409
Redirect 410 /show-error-410
Redirect 411 /show-error-411
Redirect 412 /show-error-412
Redirect 413 /show-error-413
Redirect 414 /show-error-414
Redirect 415 /show-error-415
Redirect 416 /show-error-416
Redirect 417 /show-error-417
Redirect 418 /show-error-418
Redirect 419 /show-error-419
Redirect 420 /show-error-420
Redirect 421 /show-error-421
Redirect 422 /show-error-422
Redirect 423 /show-error-423
Redirect 424 /show-error-424
Redirect 425 /show-error-425
Redirect 426 /show-error-426
Redirect 500 /show-error-500
Redirect 501 /show-error-501
Redirect 502 /show-error-502
Redirect 503 /show-error-503
Redirect 504 /show-error-504
Redirect 505 /show-error-505
Redirect 506 /show-error-506
Redirect 507 /show-error-507
Redirect 508 /show-error-508
Redirect 509 /show-error-509
Redirect 510 /show-error-510

Powerful Mod_Rewrite Trick

Here's how to combine the power of mod_rewrites ability to parse requests and environment variables with the above Redirect trick to trigger a specific ErrorDocument based on the query_string parameter error. This trick is only on AskApache.com, very powerful trick if you need to force ErrorDocuments.

RewriteCond %{QUERY_STRING} error=([4|5][0-9][0-9]) [NC]
RewriteCond %{QUERY_STRING} !404
RewriteRule . /show-error-%1 [L]

ErrorDocument Example for .htaccess

So if you save the php file as err.php in your DOCUMENT_ROOT, these are the htaccess commands that will enable its use.

The addition of the ?error=num should be unneccessary on a good linux machine, it's a way for lesser OS's and webhosts to still be able to use errordocuments. Basically Apache handles ErrorDocuments by setting special DEBUGGING variables (Start with REDIRECT_) so it's very easy to determine the STATUS CODE by just viewing $_SERVER['REDIRECT_STATUS']. If a recursive type of redirect is going on, you may see $_SERVER['REDIRECT_REDIRECT_STATUS']. Dumb (consistently) OS's like a Windows server almost always have problems with things like that, because they don't give a hoot about POSIX or standards, why should they when no one can view their code anyway. Here are some more details on the REDIRECT_STATUS and other ways to use these variables.

If you want to learn how to enumerate and view the different variables that are in your Apache environment, I think I have the best tutorial on the planet for how to do this with PHP and mod_rewrite with mod_headers. That article is the basis for anyone who is hired to do mod_rewrites on a new server without root access. I would say that one article will inform you more about mod_rewrite then any other article on this site.

###
# ErrorDocument: In the event of a problem or error, what the server will return to the client. URLs
# can begin with a / for local web-paths (relative to DocumentRoot), or be a full URL which the client
# can resolve. Alternatively, a message can be displayed.  If a malformed request is detected, normal
# request processing will be immediately halted and the internal error message returned.
#
# Prior to version 2.0, messages were indicated by prefixing them with a
# single unmatched double quote character.
#
# The special value default can be used to specify Apache's simple hardcoded message and
# will restore Apache's simple hardcoded message.
#
ErrorDocument 400 /err.php?error=400
ErrorDocument 401 /err.php?error=401
ErrorDocument 402 /err.php?error=402
ErrorDocument 403 /err.php?error=403
ErrorDocument 404 /err.php?error=404
ErrorDocument 405 /err.php?error=405
ErrorDocument 406 /err.php?error=406
ErrorDocument 407 /err.php?error=407
ErrorDocument 408 /err.php?error=408
ErrorDocument 409 /err.php?error=409
ErrorDocument 410 /err.php?error=410
ErrorDocument 411 /err.php?error=411
ErrorDocument 412 /err.php?error=412
ErrorDocument 413 /err.php?error=413
ErrorDocument 414 /err.php?error=414
ErrorDocument 415 /err.php?error=415
ErrorDocument 416 /err.php?error=416
ErrorDocument 417 /err.php?error=417
ErrorDocument 422 /err.php?error=422
ErrorDocument 423 /err.php?error=423
ErrorDocument 424 /err.php?error=424
ErrorDocument 426 /err.php?error=426
ErrorDocument 500 /err.php?error=500
ErrorDocument 501 /err.php?error=501
ErrorDocument 502 /err.php?error=502
ErrorDocument 503 /err.php?error=503
ErrorDocument 504 /err.php?error=504
ErrorDocument 505 /err.php?error=505
ErrorDocument 506 /err.php?error=506
ErrorDocument 507 /err.php?error=507
ErrorDocument 510 /err.php?error=510

PHP to handle HTTP Status Codes for ErrorDocument originally appeared on AskApache.com