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. <nick@cpanel.net>
./httpd:        HTTPD=/usr/local/cpanel/bin/chroothttpd
./cpanel:# cpanel8       Start Cpanel Services
./cpanel:# Author:       cPanel, Inc. <nick@cpanel.net>
./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. <copyright@cpanel.net>

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

Lightning Strikes Twice!

LOL..

3rd Dimension Broken with Bash!

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

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

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

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

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

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

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

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

Helpful Ncurses Programs

ALWAYS check out my functions!

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

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

Standard Capabilities

X.364 and iBCS2

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

Specified by ISO 2022

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

ISO 2022 charset switching:

• ISO/IEC 2022:1994
• "Character code structure and extension techniques"
• ECMA-035
• code structure
  • =00..=1F C0 set of control characters
  • =20..=7F G0 set of 94 or 96 graphic characters
  • =80..=9F C1 set of control characters "C1 controls"
  • =A0..=FF G1 set of 94 or 96 graphic characters
  • ... G2 and G3
• registration authority
  • ISO/IEC 2375:1985 Procedure for registration of escape sequences
  • "ECMA registry"
  • ISO-IR registration number
  • ftp://dkuug.dk/i18n/iso2375reg.txt
  • Internaltional register of coded character sets to be used with escape sequences
  • ISO/IEC JTC1/SC2/WG3
• ISO-2022 terminals from Siemens
• recode iso-2022..utf-8 not yet implemented
• CJK charsets
  • ISO-2022-JP
  • ISO-2022-JP-2
  • ISO-2022-KR
  • ISO-2022-CN
  • ISO-2022-CN-EXT

DEC private controls widely supported by emulators

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

ECMA modes

ISO 2022

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

DEC modes

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

ECMA attribute sequences

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

Init strings

Cap strings

Variable and Function Index

For stty

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

Summary of Capability Names

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

Variable and Function Index

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

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

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

Translated Term Capabilities

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

List of All Terminals

You can view this list with the following command:

$ toe -a|sort -d

VT100 keypad Diagram

VT100 LINK

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

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

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

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

SGR parameter values

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

Basic Characteristics

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

7bit vs. 8bit

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

1.6.1 Describing the Encoding

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

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

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

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

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

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

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

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

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

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

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

Terminal Type Name Conventions

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

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

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

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

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

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

MS-DOS ANSI.SYS

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

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

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

STTY

Stty Control Settings

Stty Input settings

Stty Output settings

These arguments specify output-related operations.

Stty Local settings

Stty Combination settings

cread -ignbrk brkint -inlcr -igncr icrnl -ixoff -iuclc -ixany imaxbel opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke

-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon -ixoff -iuclc -ixany -imaxbel -opost -isig -icanon -xcase min 1 time 0

Special characters

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

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

Special settings

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

Color Terminals

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

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

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

Terminals with 16 Colors

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

Terminals with 52 Colors

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

Terminals with 64 Colors

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

Terminals with 256 colors

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

View All tput capabilities

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

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

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

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

Installing your Own Terminfo

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

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

256 Colors in Terminal

256 Colors (Background)

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

256 Colors (Foreground)

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

Terminal Capabilities - Infocmp

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

DEC/ANSI special sequences

List of the DEC/ANSI special sequences recognized:

Term Sorted

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

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

TERMINAL TYPE DESCRIPTIONS SOURCE FILE

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

Just something sorta cool for you to check out

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

Terminal Escape Code Zen originally appeared on AskApache.com

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 >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

From setting the window title to show the last run command (filtered), saving your history and keeping multi-session history intact, resetting the color/cursor/highlighting of errant color-emitting commands, these 2 prompt examples do more than meet the eye and are extremely fast.

Don't have much time or just don't care? No problem, this is a simple copy and paste... here's one to start (all 1 line, just cut and paste right into the shell, once you've made sure its safe).

PS1="\n\[\033[1;30m\][$$:$PPID - \j:\!\[\033[1;30m\]]\[\033[0;36m\] \T \
\[\033[1;30m\][\[\033[1;34m\]\u@\H\[\033[1;30m\]:\[\033[0;37m\]${SSH_TTY:-o} \
\[\033[0;32m\]+${SHLVL}\[\033[1;30m\]] \[\033[1;37m\]\w\[\033[0;37m\] \n\$ "

Or for POWER PROMPT

PROMPT_COMMAND='history -a;echo -en "\033[m\033[38;5;2m"$(( `sed -n "s/MemFree:[\t ]\+\([0-9]\+\) kB/\1/p" /proc/meminfo`/1024))"\033[38;5;22m/"$((`sed -n "s/MemTotal:[\t ]\+\([0-9]\+\) kB/\1/Ip" /proc/meminfo`/1024 ))MB"\t\033[m\033[38;5;55m$(< /proc/loadavg)\033[m"'
PS1='\[\e[m\n\e[1;30m\][$$:$PPID \j:\!\[\e[1;30m\]]\[\e[0;36m\] \T \d \[\e[1;30m\][\[\e[1;34m\]\u@\H\[\e[1;30m\]:\[\e[0;37m\]${SSH_TTY} \[\e[0;32m\]+${SHLVL}\[\e[1;30m\]] \[\e[1;37m\]\w\[\e[0;37m\] \n($SHLVL:\!)\$ '
 

Or for Extreme Power Prompt

Updated! 5/25/2010, This is what I use at the moment.. It's the coolest code I've ever seen to do this. I rewrote the above (and below) bash prompts to this format because it is much more robust, and believe it or not its way faster for your machine. Yes the code below is correct, it looks a little weird to export vars from within an exported var statement.. but this is correct. If you just learn this one bit of code, you will gain a lot of shell kung fu, at least I have! Enjoy!

export AA_P="export PVE=\"\\033[m\\033[38;5;2m\"\$(( \`sed -n \"s/MemFree:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\` / 1024 ))\"\\033[38;5;22m/\"\$((\`sed -n \"s/MemTotal:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\`/ 1024 ))MB\"\\t\\033[m\\033[38;5;55m\$(< /proc/loadavg)\\033[m\";echo -en \"\""
export PROMPT_COMMAND="history -a;((\$SECONDS % 10==0 ))&&eval \"\$AA_P\";echo -en \"\$PVE\";"
export PS1="\\[\\e[m\\n\\e[1;30m\\][\$\$:\$PPID \\j:\\!\\[\\e[1;30m\\]]\\[\\e[0;36m\\] \\T \\d \\[\\e[1;30m\\][\\[\\e[1;34m\\]\\u@\\H\\[\\e[1;30m\\]:\\[\\e[0;37m\\]\${SSH_TTY} \\[\\e[0;32m\\]+\${SHLVL}\\[\\e[1;30m\\]] \\[\\e[1;37m\\]\\w\\[\\e[0;37m\\] \\n(\$SHLVL:\\!)\\\$ "
export PVE="\\033[m\\033[38;5;2m813\\033[38;5;22m/1024MB\\t\\033[m\\033[38;5;55m0.25 0.22 0.18 1/66 26820\\033[m" && eval $AA_P

[24574:16122 0:344] 05:49:07 Wed May 26 [faux@backtrack-askapache:/dev/pts/0 +1] ~
(1:344)$ export AA_P="export PVE=\"\\033[m\\033[38;5;2m\"\$(( \`sed -n \"s/MemFree:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\` / 1024 ))\"\\033[38;5;22m/\"\$((\`sed -n \"s/MemTotal:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\`/ 1024 ))MB\"\\t\\033[m\\033[38;5;55m\$(< /proc/loadavg)\\033[m\";echo -en \"\""
>>> export 'AA_P=export PVE="\033[m\033[38;5;2m"$(( `sed -n "s/MemFree:[\t ]\+\([0-9]\+\) kB/\1/p" /proc/meminfo` / 1024 ))"\033[38;5;22m/"$((`sed -n "s/MemTotal:[\t ]\+\([0-9]\+\) kB/\1/p" /proc/meminfo`/ 1024 ))MB"\t\033[m\033[38;5;55m$(< /proc/loadavg)\033[m";echo -en ""'
>>> AA_P='export PVE="\033[m\033[38;5;2m"$(( `sed -n "s/MemFree:[\t ]\+\([0-9]\+\) kB/\1/p" /proc/meminfo` / 1024 ))"\033[38;5;22m/"$((`sed -n "s/MemTotal:[\t ]\+\([0-9]\+\) kB/\1/p" /proc/meminfo`/ 1024 ))MB"\t\033[m\033[38;5;55m$(< /proc/loadavg)\033[m";echo -en ""'

[24574:16122 0:345] 05:49:09 Wed May 26 [faux@backtrack-askapache:/dev/pts/0 +1] ~
(1:345)$ export PROMPT_COMMAND="history -a;((\$SECONDS % 10==0 ))&&eval \"\$AA_P\";echo -en \"\$PVE\";"
>>> export 'PROMPT_COMMAND=history -a;(($SECONDS % 10==0 ))&&eval "$AA_P";echo -en "$PVE";'
>>> PROMPT_COMMAND='history -a;(($SECONDS % 10==0 ))&&eval "$AA_P";echo -en "$PVE";'
>>> history -a
>>> (( 66 % 10==0  ))
>>> echo -en '\033[m\033[38;5;2m813\033[38;5;22m/1024MB\t\033[m\033[38;5;55m0.35 0.24 0.19 1/68 27241\033[m'

813/1024MB      0.35 0.24 0.19 1/68 27241
[24574:16122 0:346] 05:49:09 Wed May 26 [faux@backtrack-askapache:/dev/pts/0 +1] ~
(1:346)$ export PS1="\\[\\e[m\\n\\e[1;30m\\][\$\$:\$PPID \\j:\\!\\[\\e[1;30m\\]]\\[\\e[0;36m\\] \\T \\d \\[\\e[1;30m\\][\\[\\e[1;34m\\]\\u@\\H\\[\\e[1;30m\\]:\\[\\e[0;37m\\]\${SSH_TTY} \\[\\e[0;32m\\]+\${SHLVL}\\[\\e[1;30m\\]] \\[\\e[1;37m\\]\\w\\[\\e[0;37m\\] \\n(\$SHLVL:\\!)\\\$ "
>>> export 'PS1=\[\e[m\n\e[1;30m\][$$:$PPID \j:\!\[\e[1;30m\]]\[\e[0;36m\] \T \d \[\e[1;30m\][\[\e[1;34m\]\u@\H\[\e[1;30m\]:\[\e[0;37m\]${SSH_TTY} \[\e[0;32m\]+${SHLVL}\[\e[1;30m\]] \[\e[1;37m\]\w\[\e[0;37m\] \n($SHLVL:\!)\$ '
>>> PS1='\[\e[m\n\e[1;30m\][$$:$PPID \j:\!\[\e[1;30m\]]\[\e[0;36m\] \T \d \[\e[1;30m\][\[\e[1;34m\]\u@\H\[\e[1;30m\]:\[\e[0;37m\]${SSH_TTY} \[\e[0;32m\]+${SHLVL}\[\e[1;30m\]] \[\e[1;37m\]\w\[\e[0;37m\] \n($SHLVL:\!)\$ '
>>> history -a
>>> (( 67 % 10==0  ))
>>> echo -en '\033[m\033[38;5;2m813\033[38;5;22m/1024MB\t\033[m\033[38;5;55m0.35 0.24 0.19 1/68 27241\033[m'

813/1024MB      0.35 0.24 0.19 1/68 27241
[24574:16122 0:347] 05:49:10 Wed May 26 [faux@backtrack-askapache:/dev/pts/0 +1] ~
(1:347)$ export PVE="\\033[m\\033[38;5;2m813\\033[38;5;22m/1024MB\\t\\033[m\\033[38;5;55m0.25 0.22 0.18 1/66 26820\\033[m"
>>> export 'PVE=\033[m\033[38;5;2m813\033[38;5;22m/1024MB\t\033[m\033[38;5;55m0.25 0.22 0.18 1/66 26820\033[m'
>>> PVE='\033[m\033[38;5;2m813\033[38;5;22m/1024MB\t\033[m\033[38;5;55m0.25 0.22 0.18 1/66 26820\033[m'
>>> history -a
>>> (( 67 % 10==0  ))
>>> echo -en '\033[m\033[38;5;2m813\033[38;5;22m/1024MB\t\033[m\033[38;5;55m0.25 0.22 0.18 1/66 26820\033[m'

256 Color Prompt Command

NOTE: I have been preparing a 256color terminal article for some time now, as I have tweaked, hacked, read, and experimented with more than I would ever like to admit. So stay tuned, there isn't any tutorial, book, or online howto remotely close to as good as what I'm close to posting...

If you have a 256-color enabled terminal try this..

    export PROMPT_COMMAND='echo -en "\033[m\033[38;5;2m"$(( `sed -n "s/MemFree:[\t ]\+\([0-9]\+\) kB/\1/p" /proc/meminfo`/1024))"\033[38;5;22m/"$((`sed -n "s/MemTotal:[\t ]\+\([0-9]\+\) kB/\1/Ip" /proc/meminfo`/1024 ))MB"\t\033[m\033[38;5;55m$(< /proc/loadavg)\033[m"'
    export PS1='\[\e[m\n\e[1;30m\][$$:$PPID \j:\!\[\e[1;30m\]]\[\e[0;36m\] \T \d \[\e[1;30m\][\[\e[1;34m\]\u@\H\[\e[1;30m\]:\[\e[0;37m\]${SSH_TTY} \[\e[0;32m\]+${SHLVL}\[\e[1;30m\]] \[\e[1;37m\]\w\[\e[0;37m\] \n($SHLVL:\!)\$ '

Which double-quoted is:

declare -x PROMPT_COMMAND="echo -en \"\\033[m\\033[38;5;2m\"\$(( \`sed -n \"s/MemFree:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\`/1024))\"\\033[38;5;22m/\"\$((\`sed -n \"s/MemTotal:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/Ip\" /proc/meminfo\`/1024 ))MB\"\\t\\033[m\\033[38;5;55m\$(< /proc/loadavg)\\033[m\""
declare -x PS1="\\[\\e[m\\n\\e[1;30m\\][\$\$:\$PPID \\j:\\!\\[\\e[1;30m\\]]\\[\\e[0;36m\\] \\T \\d \\[\\e[1;30m\\][\\[\\e[1;34m\\]\\u@\\H\\[\\e[1;30m\\]:\\[\\e[0;37m\\]\${SSH_TTY} \\[\\e[0;32m\\]+\${SHLVL}\\[\\e[1;30m\\]] \\[\\e[1;37m\\]\\w\\[\\e[0;37m\\] \\n(\$SHLVL:\\!)\\\$ "

For Commandlinefu.com users: Here ya go! toprc

That looks great, and is practicallly totally free in terms of how much cpu/work it makes the shell do for each command. So for slow terminals, or text-terminals like I use, this is great. Other than PS1, there is 1 other variable.. It's called PROMPT_COMMAND and is execed right in front of the PS1. I show 2 ways to utilize this, the goal being to show there is no right way.. fast is fast and money is money. I use a function called aa_pc I threw together that shows me in color how much memory is on my system.. very cool.

PROMPT = ?

Here's a screenshot of the code in my vim + screen multiplexed bash 4 environment.. It's placed all the way at the bottom of the file and is the last thing executed by the client processing the script. Also, while it's great to look so good, this is all 100% for efficiency since I use one shell or another every day.

Custom Power Prompt - currently mine

Here's the code I'm using today, that produced this screen-shot -- I am always changing stuff so it's a little more tough to figure out.

  function aa_pc()
  {
        local M=$( free -olm|sed "/Mem/!d; s/Mem:[^0-9]*\([0-9]*\)[^0-9]*\([0-9]*\)[^0-9]*\([0-9]*\).*/ \
        ${GREP_COLOR}\2MB${R}\/\3MB/"; ); echo -e "$M `pwd`"
  }
 
  aa_grep_color(){ export GREP_COLOR=`tput setaf $(aa_random_under 6)`; }
  aa_random_under(){ echo -en $(( $RANDOM % ${1:-$RANDOM} + 1 )); }
  uptime1(){ sed '/.*,  \([0-9]*\) users,  load average: \(.*\)/!d; s//[ \2, \1 users ]/;q';
 
  $SED -n '/i/!Q2' <<< $- && \
  {
        case ${TERM:-dummy} in xterm*|screen*|*color*)echo; ;; *) return; esac;
  }
 
  # hack for being able to source all the functions in this file from a script
  MASTER_RESET=$`echo -e "rs1\nrs2\ninitc\nis2\ncnorm\nrmso\nsgr0" | tput -S`
 
  # only for color-aware (some guessing) terminals, kick everyone else OUT
  case ${TERM:-dummy} in xterm*|screen*|*color*)echo; ;; *) return; esac;
 
  [[ -r /etc/DIR_COLORS ]] && eval `dircolors -b /etc/DIR_COLORS`
 
  # changes the window title in terminals like putty or konsole
  echo -ne "\033]0; ${USER}@${HOSTNAME}  +${SHLVL} @${SSH_TTY/\/dev\/} - `uptime1` \007"
 
  # show title, setup the colors, vars, funcs, settings
  asetup_colors && ascript_title
  export PROMPT_COMMAND='history -a;aa_pc'
  export PS1='\[\033[1;30m\][$$:$PPID - \j:\!\[\033[1;30m\]]\[\033[0;36m\] \T\
  \d \[\033[1;30m\][\[\033[1;34m\]\u@\H\[\033[1;30m\]:\[\033[0;37m\]${SSH_TTY} \
  \[\033[0;32m\]+${SHLVL}\[\033[1;30m\]] \[\033[1;37m\]\w\[\033[0;37m\] \n\$ '

I've used many shells over the years and have learned many tweaks and tricks for a powerful prompt. It may look deceptively simple. One cool thing this prompt does is display the command line (filtered) in the putty/konsole/xterm window, so if you have several windows minimized you can easily find the one you are looking for.

There is a lot of good info about the BASH prompt around the net, but it can be complicated for a new user, and as an advanced user you will notice most of the info is very outdated and not very optimized for speed. To get this articles recommended prompt working is devastatingly simple, just export the PROMPT_COMMAND and PS1 variables that are shown below. Most "power prompts" that utilize things like PROMPT_COMMAND do so very haphazardly or very extravagantly.

I've been called a lot of things but not extravagant, and because I use this prompt on many different servers, platforms, and systems I made sure to not make things complicated. To test them just copy and paste the code below into your shell which will export PROMPT_COMMAND and PS1 variables and work right away. So test it out, and if you like it add it to your .bashrc or other startup file (please do a $ man bash).

• Custom Power Prompt Commands
  1. PROMPT_COMMAND Detailed
  2. PS1 Detailed
• Additional Info for Hackers
  1. Setting Window Title
  2. Stripping Colors from PS1
  3. Alternative to Uptime/Loadavg (proc)
  4. Multi-Prompt Switcher Function
• Bash Prompts - More Reading
  1. Other Simple Power Prompt Examples
  2. All Prompt Variables
  3. Escape Codes for PS1
  4. Additional Reading

Bash Power Prompt

From setting the window title to show the last run command (filtered), saving your history and keeping multi-session history intact, resetting the color/cursor/highlighting of errant color-emitting commands, this prompt does more than meets the eye extremely fast.

Don't have much time? Don't care? You may copy and paste these 2 lines into your shell and that's all there is to it!

export PROMPT_COMMAND='export H1="`history 1|sed -e "s/^[\ 0-9]*//; s/[\d0\d31\d34\d39\d96\d127]*//g; s/\(.\{1,50\}\).*$/\1/g"`";history -a;echo -e "sgr0\ncnorm\nrmso"|tput -S'
export PS1='\n\e[1;30m[\j:\!\e[1;30m]\e[0;36m \T \d \e[1;30m[\e[1;34m\u@\H\e[1;30m:\e[0;37m`tty 2>/dev/null` \e[0;32m+${SHLVL}\e[1;30m] \e[1;37m\w\e[0;37m\[\033]0;[ ${H1}... ] \w - \u@\H +$SHLVL @`tty 2>/dev/null` - [ `uptime` ]\007\]\n\[\]\$ '

PROMPT_COMMAND

This holds commands to be run prior to displaying the prompt. Let's break it down.

First this takes the last command executed and filters it using sed to remove the initial history command number, and also to remove any quotes (single or double) and/or backticks. Also, it only saves the first 50 chars, which are then exported as the value of H1, which because it is exported is now globally accessible to the rest of the shell. This is important because we use this variable in PS1 to print the last run command as the title of our putty window (or konsole).

export H1=`history 1 | sed -e 's/^[\ 0-9]*//; s/[\d0\d31\d34\d39\d96\d127]*//g; s/\(.\{1,50\}\).*$/\1/g'`

The next command simply appends your last command to the history file. Usually this is ~/.bash_profile, or whatever $HISTFILE is. This makes sure you never lose history in case of a shell crash or ssh connection terminated.

history -a

Finally there is this golden nugget of shell kung-fu. This outputs 3 terminal escape sequences according to the terminal in use and its capabilities.. so very robust, should work on any shell newer than 1984. By echoing the following 3 term names separated by a newline \n and using tput -S it will output the terminal sequences for all 3. sgr0 resets the colors, cnorm resets the cursor, and rmso resets the background color.

You can view the escape sequences generated by tput with strace, cat -t, etc.. For instance on my shell (xterm-256color via portaputty) the below command generates: \33(B\33[m\33[?12l\33[?25h\33[27m. This is helpful because if you aren't coding for several terminals you can hard code that in your echo's instead of using tput, saving some overhead.

echo -e 'sgr0\ncnorm\nrmso' | tput -S
# For my term this is the same as if I just did
# echo -e "\33(B\33[m\33[?12l\33[?25h\33[27m"

PS1 Detailed

PS1 is the variable that is expanded as your prompt. So if you did a $ unset PS1 then you can still run commands and everything, but your screen will be blank which is confusing to say the least.

This PS1 shows which SHLVL level the shell is in, which is how many levels deep of shells you are currently at. If you run $ bash -l from a bash shell it will create a new instance of bash as a child of the calling bash, so the SHLVL (shell level) gets incremented by 1. I usually avoid creating subshells by instead executing a new bash with exec which instead of creating a new bash as a child of the current bash, it replaces the current bash process with the new one: $ exec bash -l.

export PS1='\n\e[1;30m[\j:\!\e[1;30m]\e[0;36m \T \d \e[1;30m[\e[1;34m\u@\H\e[1;30m:\e[0;37m`tty 2>/dev/null` \e[0;32m+${SHLVL}\e[1;30m] \e[1;37m\w\e[0;37m\[\033]0;[ ${H1}... ] \w - \u@\H +$SHLVL @`tty 2>/dev/null` - [ `uptime` ]\007\]\n\[\]\$ '
 
# with nocolors
# export PS1='\n[\j:\!] \T \d [\u@\H:`tty 2>/dev/null` +${SHLVL}] \w\[\033]0;[ ${H1}... ] \w - \u@\H +$SHLVL @`tty 2>/dev/null` - [ `uptime` ]\007\]\n\[\]\$ '

TTY

This command is very useful for me because I use multiplexed terminals, about 6 at a time, so it is crucial sometimes to know which tty I am using. Since SSH is the ONLY protocol I ever use for anything, I used to depend on the SSH_TTY variable being set instead of using tty, which as a command has more overhead then just echoing a variable. But I found that when running multiplexing terminals with tmux, screen, etc.. the SSH_TTY variable stays with the initial tty created upon login. Note: 2>/dev/null redirects any errors that running the tty command might issue to the /dev/null device, which is the same thing as a black hole, it goes nowhere so is an efficient way to send data for deletion. Depending on your server and ssh settings you may not even have a tty or it may just appear that you do not. Some web hosting companies do odd things to prevent their users from using tty devices and programs. But if you get a little creative you can always find the current tty.. like $ readlink /proc/self/fd/0 will return the same thing as $ tty.

`tty 2>/dev/null`

Changing Window Title with PS1

This simple bash function changes the title of the window to the passed parameter. The key thing to note is that this works because of the special escapes on either end of the echo'd data.

function set_window_title()
{
  echo -e "\033]0; ${1:-$USER@$HOST - $SHLVL} \007";
}

Additional Info for Hackers

More reading and digging.

Strip Colors for Readability

You can use this command to strip a PS1 of all colors, which shortens the variable dramatically in some cases.

sed 's/\\[eE][[0-9]*;[0-9]*m//g' <<< $PS1
# ie export PS1=$(sed 's/\\[eE][[0-9]*;[0-9]*m//g' <<< $PS1);

Multi-Prompt Switcher Function

This function demonstrates 1 way that you can change your prompts at will. It creates an array named AAPS that you can add as many PS1 values to as you want. Each time the function is run it simply changes the prompt string variable PS1 to the value of the next item in the AAPS array. Once it reaches the last item in AAPS, it resets back to the first AAPS[0] prompt. Just an example to play with, not tested very much.

aa_multi_prompt ()
{
    declare -a AAPS;
    AAPS[0]='\n[\j:\!] \T \d [\u@\H:`tty 2>/dev/null` +${SHLVL}] \w\[\033]0;[ ${H1}... ] \w - \u@\H +$SHLVL @`tty 2>/dev/null` - [ `uptime` ]\007\]\n\[\]\$';
    AAPS[1]='\n[\j:\!] \T \d \n[\u@\H:`tty 2>/dev/null` +${SHLVL}] \w\[\033]0;[ ${H1}... ] \w - \u@\H +$SHLVL @`tty 2>/dev/null` - [ `uptime` ]\007\]\n\[\]\$';
 
    : ${PLVL:=0};
    [[ "${#AAPS[@]}" -lt "$PLVL" || "${#AAPS[@]}" -eq "$PLVL" ]] && PLVL=0;
    export PS1=${AAPS[$PLVL]} && (( PLVL++ )) && export PLVL
}

BASH 4 Multi-Prompt

Here's an example from bash-4, but it works for all bash versions.

prompt ()
{
    case "$1" in
        d)
            PS1='$(dirs) \$ '
        ;;
        n)
            PS1='\$ '
        ;;
        hsw)
            PS1='\h[$SHLVL]: \w \$ '
        ;;
        hw)
            PS1='\h: \w \$ '
        ;;
        sh)
            PS1='[$SHLVL] \h\$ '
        ;;
        sw)
            PS1='[$SHLVL] \w \$ '
        ;;
        uh)
            PS1='\u@\h\$ '
        ;;
        uhsHw)
            PS1='\u@\h[$SHLVL]:\#: \w \$ '
        ;;
        uhsw)
            PS1='\u@\h[$SHLVL]: \w \$ '
        ;;
        uhw)
            PS1='\u@\h: \w \$ '
        ;;
        uw)
            PS1='(\u) \w \$ '
        ;;
        w)
            PS1='\w \$ '
        ;;
    esac
}

Alternative to uptime:

echo "Up for $(( $(sed 's/^\([0-9]*\).*/\1/' /proc/uptime) / (60*60*24) )) days - [`cat /proc/loadavg`]"
# or
echo "Uptime: $(( `sed 's/^\([0-9]*\).*/\1/g' /proc/uptime` / 86400 )) days. Load: $(</proc/loadavg)"

Bash Prompts - More Reading

All Bash Prompt Variables

These are the environment variables provided by BASH (and most shells) and control your prompt string. While all are interesting and good to know about, PROMPT_COMMAND and PS1 are the only ones that directly modify the prompt that is displayed.

PROMPT_COMMAND

If set, the value is executed as a command prior to issuing each primary prompt.

PS1

The value of this parameter is expanded and used as the primary prompt string. The default value is "\s-\v\$ ".

PS2

The value of this parameter is expanded as with PS1 and used as the secondary prompt string. The default is "> ".

PS3

The value of this parameter is used as the prompt for the select command.

PS4

The value of this parameter is expanded as with PS1 and the value is printed before each command bash displays during an execution trace. The first character of PS4 is replicated multiple times, as necessary, to indicate multiple levels of indirection. The default is "+".

Prompt Escape Codes

When executing interactively, bash displays the primary prompt PS1 when it is ready to read a command and the secondary prompt PS2 when it needs more input to complete a command. Bash allows these prompt strings to be customized by inserting a number of backslash-escaped special characters that are decoded as follows:

• \a - an ASCII bell character (07)
• \d - the date in "Weekday Month Date" format (e.g., "Tue May 26")
• \D{format} - the format is passed to strftime(3) and the result is inserted into the prompt string; an empty format results in a locale-specific time representation. The braces are required
• \e - an ASCII escape character (033)
• \h - the hostname up to the first '.'
• \H - the hostname
• \j - the number of jobs currently managed by the shell
• \l - the basename of the shellâs terminal device name
• \n - newline
• \r - carriage return
• \s - the name of the shell, the basename of $0 (the portion following the final slash)
• \t - the current time in 24-hour HH:MM:SS format
• \T - the current time in 12-hour HH:MM:SS format
• \@ - the current time in 12-hour am/pm format
• \A - the current time in 24-hour HH:MM format
• \u - the username of the current user
• \v - the version of bash (e.g., 2.00)
• \V - the release of bash, version + patch level (e.g., 2.00.0)
• \w - the current working directory, with $HOME abbreviated with a tilde
• \W - the basename of the current working directory, with $HOME abbreviated with a tilde
• \! - the history number of this command
• \# - the command number of this command
• \$ - if the effective UID is 0, a #, otherwise a $
• \nnn - the character corresponding to the octal number nnn
• \\ - a backslash
• \[ - begin a sequence of non-printing characters, which could be used to embed a terminal control sequence into the prompt
• \] - end a sequence of non-printing characters

The command number and the history number are usually different: the history number of a command is its position in the history list, which may include commands restored from the history file, while the command number is the position in the sequence of commands executed during the current shell session. After the string is decoded, it is expanded via parameter expansion, command substitution, arithmetic expansion, and quote removal, subject to the value of the promptvars shell option, which if set, prompt strings undergo parameter expansion, command substitution, arithmetic expansion, and quote removal after being expanded as described in PROMPTING above. promptvars is enabled by default.

More Example Prompts

export PS1="\n\e[1;37m[\e[0;32m\u\e[0;35m@\e[0;32m\h\e[1;37m]\e[1;37m[\e[0;31m\w\e[1;37m]\n$ \e[0m"
[user@host][~/bin/tools]
$

export PS1="\n[$?]\e[1;37m[\e[0;32m\u\e[0;35m@\e[0;32m\h\e[1;37m]\e[1;37m[\e[0;31m\w\e[1;37m]($SHLVL:\!)\n\[\033[0m\]\$ "
[0][user@host][~/bin/tools](1:2130)

export PS1='\[\033[1;33m\]\u\[\033[1;37m\]@\[\033[1;32m\]\h\[\033[1;37m\]:\[\033[1;31m\]\w \[\033[1;36m\]\$ \[\033[0m\]'
user@host:~/bin/tools $

export PS1="\e[1;31m[\h]$NC \W > \[\033]0;\${TERM} [\u@\h] \w\]"
[lifesaver] tools >

Benchmarking PROMPT_COMMAND

When figuring out how resource intensive your prompt_command is (if you choose to do that sort of thing), it's nice to do it like this. I ended up using this information from the following test to create the prompt_command used in the first 256-color prompt above.

#!/bin/bash
 
function clean_results()
{
      grep ^real | cut -dm -f2 | sort | uniq -c | sort -n
}
 
for i in {0..500};
do
      time sh -c "expr `sed -nu 's/^MemFree:[\t ]\+\([0-9]\+\) kB/\1/Ip' /proc/meminfo`/1024" &>/dev/nulll;
done 2>&1 | clean_results
 
# print separating line
printf "%$((${COLUMNS:-`tput cols`} - 10))s\n" ' ' | sed -u 's/ /-/g'
 
for i in {0..500};
do
      time sh -c "echo $(( `sed -nu 's/^MemFree:[\t ]\+\([0-9]\+\) kB/\1/Ip' /proc/meminfo`/1024 ))" &>/dev/null;
done 2>&1 | clean_results
 
exit $?

Generates this output, meaning that using expr takes longer.

      1 0.011s
      1 0.014s
      2 0.009s
      2 0.012s
      5 0.008s
     12 0.004s
     47 0.007s
    215 0.005s
    216 0.006s
---------------------------------------------------------------------
      1 0.003s
      2 0.007s
     59 0.006s
    196 0.004s
    243 0.005s

Additional Links

• From Power Up To Bash Prompt - TLDP
• Bash Prompt HOWTO -TLDP
• A Sample .bashrc File - TLDP
• Gentoo Linux Howtos: bash -> Bash Prompt Howto - Gentoo
• Fancy Bash Prompts - Debian Administration

Crazy POWERFUL Bash Prompt originally appeared on AskApache.com

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

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

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

Introducing tmpfs

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

Beware of WebHosts

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

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

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

Hosting Company Tricks

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

Why it gets Evil

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

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

Where it gets Evil

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

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

Where it gets Fun (for me)

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

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

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

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

TMPFS kills the RAMDISK

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

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

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

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

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

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

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

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

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

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

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

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

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

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

TMPFS uses RAM+SWAP

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

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

Swap

Find the swap size.

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

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

Using TMPFS for Cache

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

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

Boosting Cache with TMPFS

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

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

Create TMPFS at wp-content/cache

/etc/fstab

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

Restoring TMPFS across Reboots

In /etc/rc.local

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

Mirroring TMPFS to Disk

Cronjob entry

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

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

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

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

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

Resize /dev/shm

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

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

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

Securing and Using /tmp

• Secure temporary folders on existing Unix or Linux systems
• Encrypt Storage and Swap Space

tmpfs mount parameters

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

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

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

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

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

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

Using tmpfs for /tmp storage

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

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

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

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

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

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

Bind Mounts

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

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

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

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

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

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

Bind mounting and /dev/shm

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

tmpfs  /dev/shm  tmpfs  defaults  0 0

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

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

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

/etc/default/tmpfs WorkAround

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

RSYNC vs. CP

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

Mount Options

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

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

Filesystems

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

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

/etc/fstab

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

From /etc/mtab

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

From /proc/mounts

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

/etc/fstab

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

This file is used in three ways:

1. The following command (usually given in a bootscript) causes all file systems mentioned in fstab (of the proper type and/or having or not having the proper options) to be mounted as indicated, except for those whose line contains the noauto keyword. Adding the -F option will make mount fork, so that the filesystems are mounted simultaneously.

   mount -a [-t type] [-O optlist]

2. When mounting a file system mentioned in fstab, it suffices to give only the device, or only the mount point.
3. Normally, only the superuser can mount file systems. However, when fstab contains the user option on a line, anybody can mount the corresponding system.

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

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

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

The first field, (fs_spec)

Describes the block special device or remote filesystem to be mounted. For ordinary mounts it will hold (a link to) a block special device node (as created by mknod(8)) for the device to be mounted, like ‘/dev/cdrom’ or ‘/dev/sdb7’. For NFS mounts one will have <host>:<dir>, e.g., ‘knuth.aeb.nl:/’. For procfs, use ‘proc’.

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

The second field, (fs_file)

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

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

The fourth field, (fs_mntops)

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

Common for all types of file system are the options:

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

The fifth field, (fs_freq)

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

The sixth field, (fs_passno)

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

More Reading

• Overview of RAMFS and TMPFS on Linux
• ramfs, rootfs and initramfs
• Tmpfs is a file system which keeps all files in virtual memory
• IBM: Advanced filesystem implementor's guide, Part 3
• TMPFS Wikipedia Entry
• Shared Memory
• Create turbocharged storage using tmpfs
• Where MySQL Stores Temporary Files
• speeding up firefox with tmpfs and automatic rsync (shell-script) Original
• kernel documentation for tmpfs
• initscripts: please don't mount /dev/shm noexec
• HOWTO: Using tmpfs for /tmp, /var/{log,run,lock...}
• Gentoo Forums: Using tmpfs for /var/{log,lock,...}
• [TIP] Firefox and tmpfs: a surprising improvement

Experiment: MySQL tmpdir on tmpfs

In MySQL, the tmpdir path is mainly used for disk-based sorts (if the sort_buffer_size is not enough) and disk-based temp tables. The latter cannot always be avoided even if you made tmp_table_size and max_heap_table_size quite large, since MEMORY tables don’t support TEXT/BLOB type columns, and also since you just really don’t want to run the risk of exceeding available memory by setting these things too large.

Use tmpfs for MySQL

--tmpdir=path, -t path

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

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

Shell Script for Firefox tmpfs

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

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

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

The bottom line for this article is that I want to make WordPress as fast, secure, and easy to install, run, and manage because I am using it more and more for client production sites, I will work for days in order to solve an issue so that I never have to spend time on that issue again. Time is money in this industry and that is ultimately (time) what there is to gain by tweaking WordPress.

Note: I spent no time on readability, this is primarily a read the code and figure it out article.. This is for advanced users looking for a reference or discussion and for those of you looking to advance. Feedback would be great if you make it that far..

For a better handle on the way I like to structure web site directories, see Optimize a Website for Speed, Security, and Easy Management but note it is a bit outdated compared to what I'm doing now. I don't have the luxury of using only one type of server, or hosting provider anymore, so I have been working towards making things even more portable in order to move from host to host from server to server without issues i.e. my portable .bash_profile.

So I've been basically experimenting various ways to accomplish that and thought I would share what I am currently doing for my benefit and hopefully get some input. All of my WP installs run the development version, and one main idea with my setups is that upgrading is automated. So I really keep the WordPress install clean and use plugins and wp-config.php to do all the customization.

• Portability - Hands-free upgrades and easy to move
• Security - Additional security and protection
• Speed - Less CPU and Disk I/O
• Customization - All my favorite customizations

wp-config.php

These are the main settings I use.. Seriously this is more like an interactive article, because to understand it you will need to do some code grepping. You may want to grab a jolt.

ASKAPACHE_ROOT

The ASKAPACHE_ROOT variable is just a better way for me to be able to include and access all the different files in my site tree. For instance, in my non-wp php files, I can do this:

!defined('ASKAPACHE_ROOT') && require $_SERVER['DOCUMENT_ROOT'] . '/wp-config.php';
include(ASKAPACHE_ROOT . '/includes/custom-download.inc.php');

ASKAPACHE_LOCK

This is one of my all-time favorite hacks, that I think is one of the most useful methods I employ as a web developer. This allows me to use far-future-expire headers for optimum caching, while still forcing browsers to re-validate every day or so automatically, or forcing them to re-validate whenever I change the suffix. This takes advantage of the mod_rewrite trick that I use on EVERY site I run, definately worth learning. Because I practice best-practice web-standards, for every web site I create a single css file and javascript file, which I then add to the template like:

<link rel="stylesheet" type="text/css" media="all" href="http://static.askapache.com/c/apache-0<?php echo ASKAPACHE_LOCK?>.css" />
<script src="http://static.askapache.com/j/apache-0<?php echo ASKAPACHE_LOCK;?>.js" type="text/javascript"></script>

<?php
/**
 * The base configurations of the WordPress.
 *
 * This file has the following configurations: MySQL settings, Table Prefix,
 * Secret Keys, WordPress Language, and ABSPATH. You can find more information by
 * visiting {@link http://codex.wordpress.org/Editing_wp-config.php Editing
 * wp-config.php} Codex page. You can get the MySQL settings from your web host.
 *
 * This file is used by the wp-config.php creation script during the
 * installation. You don't have to use the web site, you can just copy this file
 * to "wp-config.php" and fill in the values.
 *
 * @package WordPress
 */
/* http://codex.wordpress.org/Editing_wp-config.php */
 
/** /home/liet/askapache.com */
!defined('ASKAPACHE_ROOT') && define('ASKAPACHE_ROOT', str_replace('/public_html','', $_SERVER['DOCUMENT_ROOT']));
 
/** The 008 at the end is for manual tweaking.  time() returns seconds since '00:00:00 1970-01-01 UTC'. */
// http://www.askapache.com/htaccess/mod_rewrite-fix-for-caching-updated-files.html
!defined('ASKAPACHE_LOCK') && define(ASKAPACHE_LOCK', substr(time(),0,5).'008'); // 12533001
 
/** absolute path to the WordPress directory */
!defined('ABSPATH') && define('ABSPATH', ASKAPACHE_ROOT .'/public_html/');
 
/**
 * WP_SITEURL, defined since WordPress Version 2.2, allows the WordPress address (URL) to be defined. The valued defined is the address where your WordPress core files reside.
 * It should include the http:// part too. Do not put a slash "/" at the end.
 * Setting this value in wp-config.php overrides the wp_options table value for siteurl and disables the WordPress address (URL) field in the Administration > Settings > General panel.
 */
!defined('WP_SITEURL') && define('WP_SITEURL', 'http://'.$_SERVER['SERVER_NAME']);
 
/**
 * WP_HOME is another wp-config.php option added in WordPress Version 2.2. Similar to WP_SITEURL,
 * WP_HOME overrides the wp_options table value for home but does not change it permanently.
 * home is the address you want people to type in their browser to reach your WordPress blog. It should include the http:// part. Also, do not put a slash "/" at the end.
 */
!defined('WP_HOME') && define('WP_HOME', WP_SITEURL);
 
/** no trailing slash, full paths only */
!defined('WP_CONTENT_DIR') && define( 'WP_CONTENT_DIR', ABSPATH . 'wp-content' );
 
// full url - WP_CONTENT_DIR is defined further up
!defined('WP_CONTENT_URL') && define( 'WP_CONTENT_URL', WP_SITEURL . '/wp-content');
 
/** Allows for the plugins directory to be moved from the default location. @since 2.6.0 */
// full path, no trailing slash
!defined('WP_PLUGIN_DIR') && define( 'WP_PLUGIN_DIR', WP_CONTENT_DIR . '/plugins' );
 
/** Allows for the plugins directory to be moved from the default location. @since 2.6.0 */
// full url, no trailing slash
!defined('WP_PLUGIN_URL') && define( 'WP_PLUGIN_URL', WP_CONTENT_URL . '/plugins' );
 
/** Allows for the plugins directory to be moved from the default location. @since 2.1.0 */
// Relative to ABSPATH.  For back compat.
//!defined('PLUGINDIR') && define( 'PLUGINDIR', 'wp-content/plugins' );
 
/** Number of autosaves to save. TRUE is default and enables post revisions, FALSE disables revisions completely. */
!defined('WP_POST_REVISIONS') && define('WP_POST_REVISIONS', 150);
 
/* ini_set('memory_limit', WP_MEMORY_LIMIT); */
!defined('WP_MEMORY_LIMIT') && define('WP_MEMORY_LIMIT', '64M');
 
/** Only check at this interval for new messages. Default is 5min */
/** @since 2.9  */
!defined('WP_MAIL_INTERVAL') && define('WP_MAIL_INTERVAL', 3600); // 1 hour
 
/** Saves updated post values to post from edit window every x seconds. (default 60)
 * When editing a post, WordPress uses Ajax to auto-save revisions to the post as you edit. You may want to increase this setting for longer delays in between auto-saves, or decrease the setting to make sure you never lose changes.
 * @since 2.5.0 */
!defined( 'AUTOSAVE_INTERVAL' ) && define( 'AUTOSAVE_INTERVAL', 60 );
 
/** @since 2.9.0  */
/** Permanently deletes posts, pages, attachments, and comments which have been in the trash for EMPTY_TRASH_DAYS. */
!defined( 'EMPTY_TRASH_DAYS' ) && define( 'EMPTY_TRASH_DAYS', 300 );

Debugging WordPress

One of my secrets for getting really good at this stuff is to master debugging. There is really not ever a time when I am working on a site that I don't have color-highlighted logs scrolling automatically in an ssh window. It's really almost impossible to fix problems with wordpress or do any kind of advanced anything without being able to view debugging info. At first I relied heavily on a custom php.ini being available on the server, but after having to deal with many hosts who don't allow php.ini files I now rely completely on setting values using ini_set for ultimate portability. Detailed towards the end of this article and is also included in this wp-config.php

/**#@+
 * DEBUGGING STUFF
 */
/** display of notices during development. if false, error_reporting is E_ERROR | E_WARNING | E_PARSE | E_USER_ERROR | E_USER_WARNING | E_RECOVERABLE_ERROR otherwise E_ALL */
!defined('WP_DEBUG') && define('WP_DEBUG', false);
 
/** The SAVEQUERIES definition saves the database queries to a array and that array can be displayed to help analyze those queries.
 *  The information saves each query, what function called it, and how long that query took to execute.  */
!defined('SAVE_QUERIES') && define('SAVE_QUERIES', WP_DEBUG);
 
!defined('ACTION_DEBUG') && define('ACTION_DEBUG', WP_DEBUG);
 
/** This will allow you to edit the scriptname.dev.js files in the wp-includes/js and wp-admin/js directories.  */
!defined('SCRIPT_DEBUG') && define('SCRIPT_DEBUG', WP_DEBUG);
 
/** Add define('WP_DEBUG_LOG', true); to enable php debug logging to WP_CONTENT_DIR/debug.log */
//!defined('WP_DEBUG_LOG') && define('WP_DEBUG_LOG', true);
 
/** This determines whether errors should be printed to the screen as part of the output or if they should be hidden from the user.
 *  Add define('WP_DEBUG_DISPLAY', false); to wp-config.php to use the globally configured setting for display_errors and not force it to On */
!defined('WP_DEBUG_DISPLAY') && define('WP_DEBUG_DISPLAY', false);

Ultimate Security Tweaks

Well, ultimate for WP's built-in keys and password functions, this is all for wp-config.php keep in mind. This is a very neccessary and recommended step, and is one of the only things I modify for each new installation.

Security KEYS

If like me you are familiar with password-cracking software like John the ripper, rainbow hash tables, l0pht-crack, etc.. then you will like to know that you can specify your own keys and salts for the encryption used by WP. They are AUTH_KEY, AUTH_SALT, SECURE_AUTH_KEY, SECURE_AUTH_SALT, LOGGED_IN_KEY, LOGGED_IN_SALT, NONCE_KEY, NONCE_SALT, SECRET_KEY and SECRET_SALT.

A random and long key gives you better encryption, and exponentially increasing that is using a random and long salt for the encryption. Encryptions with known salts are incredibly easy to decrypt compared to encryptions with secure salts, because the salt + key individually need to be guessed in order to find a matching hash, vs. just the key if the salt is known. See: Locating weak passwords.

A secret key is a hashing salt which makes your site harder to hack and access harder to crack by adding random elements to the password.

In simple terms, a secret key is a password with elements that make it harder to generate enough options to break through your security barriers. A password like "password" or "test" is simple and easily broken. A random, unpredictable password such as "88a7da62429ba6ad3cb3c76a09641fc" takes years to come up with the right combination.

For more information on the technical background and breakdown of secret keys and secure passwords, see:

• WordPress Support Forum - HOWTO: Set up secret keys in WordPress 2.6+
• Wikipedia's explanation of Password Cracking

I like to use the WordPress.org secret-key service 4 times. That's because for each key and salt I like to do: (1 key from api +random keyboard input+1 key from api).

/**#@+
 * Authentication Unique Keys.
 *
 * Change these to different unique phrases!
 * You can generate these using the {@link https://api.wordpress.org/secret-key/1.1/ WordPress.org secret-key service}
 * You can change these at any point in time to invalidate all existing cookies.
 * This will force all users to have to log in again.
 *
 * @since 2.6.0
 *
 * Get salt to add to hashes to help prevent attacks.
 *
 * The secret key is located in two places: the database in case the secret key
 * isn't defined in the second place, which is in the wp-config.php file. If you
 * are going to set the secret key, then you must do so in the wp-config.php
 * file.
 *
 * The secret key in the database is randomly generated and will be appended to
 * the secret key that is in wp-config.php file in some instances. It is
 * important to have the secret key defined or changed in wp-config.php.
 *
 * If you have installed WordPress 2.5 or later, then you will have the
 * SECRET_KEY defined in the wp-config.php already. You will want to change the
 * value in it because hackers will know what it is. If you have upgraded to
 * WordPress 2.5 or later version from a version before WordPress 2.5, then you
 * should add the constant to your wp-config.php file.
 *
 * Below is an example of how the SECRET_KEY constant is defined with a value.
 * You must not copy the below example and paste into your wp-config.php. If you
 * need an example, then you can have a
 * {@link https://api.wordpress.org/secret-key/1.1/ secret key created} for you.
 *
 * Salting passwords helps against tools which has stored hashed values of
 * common dictionary strings. The added values makes it harder to crack if given
 * salt string is not weak.
 *
 * @since 2.5
 * @link https://api.wordpress.org/secret-key/1.1/ Create a Secret Key for wp-config.php
 *
 * @return string Salt value from either 'SECRET_KEY' or 'secret' option
 */
define('AUTH_KEY',        'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?p[B+GR{@>{Yq`c|LnG;dvq#| %OA_cbBSU6,rICC1o/c)-|');
define('SECURE_AUTH_KEY', 'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?Vp[Bb15baar8&R-r<[T|?(xhJJABGq+Ux+U$)-Hltp/');
define('LOGGED_IN_KEY',   'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?Vp[B<5n6DG|YWnJ9tY2!M1L)`{-$LW~~Ia%.uCbn!P. 41o2$Z$4');
define('NONCE_KEY',       'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?Vp[Bgu<wM*zewR0.{+m:bmrB?wj!B,4]Wo+4 Avk ApR-D?E');
define('SECRET_KEY',     'jflkhaskljdfhkljasdhflkjashd;flkjhas;djfh;kajshdflkjashdlfkjhasdlkfhal?Vp[B52ugH6muE9r4._iZwoYKUybrqLPpv|d Xr+|yrqhUE');
 
define('AUTH_SALT',        '123423190847olqkfhladhfsldshafasdfasdf09a7f-90a87df98adfyapoiyaf9asd8f70a9s8d7f908a7sdf97W4qCdm~Ky%+%~PPa5b YEmDI%U[W!-B');
define('SECURE_AUTH_SALT', '123423190847olqkfhladhfsldshafasdfasdf09a7f-90a87df98adfyapoiyaf9asd8f70a9s8d7f908a7sdf97W4qCdmad/7o6.AU3%9o-|Kqm]+eUqr-n~:ag');
define('LOGGED_IN_SALT',   '123423190847olqkfhladhfsldshafasdfasdf09a7f-90a87df98adfyapoiyaf9asd8f70a9s8d7f908a7sdf97W4qCdmsLiCv@KJ{#wd(?qe(KcH3!');
define('NONCE_SALT',       '123423190847olqkfhladhfsldshafasdfasdf09a7f-90a87df98adfyapoiyaf9asd8f70a9s8d7f908a7sdf97W4qCdmG9>+wm 2)bS0Pd_+1rx0brX]ND8|');
define('SECRET_SALT',      '123423190847olqkfhladhfsldshafasdfasdf09a7f-90a87df98adfyapoiyaf9asd8f70a9s8d7f908a7sdf97W4qCdm2<>))U|sty)+4vpWooKls/^[vN');
/**#@-*/

Using SSL for Admin and Login

SSL is kinda required from my point of view, it is just way to easy to sniff data off the wire otherwise. At least with SSL you force them to use tools like burpsuite, paros proxy, webscarab, etc..

/** @since 2.6.0  */
!defined('FORCE_SSL_ADMIN') && define('FORCE_SSL_ADMIN', true);
 
/** @since 2.6.0  */
!defined('FORCE_SSL_LOGIN') && define('FORCE_SSL_LOGIN', true);

Mod_Rewrite to Force SSL

This is pretty cool, it forces non-https for all urls except for /wp-admin and wp-login.php, which both require https. It also checks for the logged_in_cookie, and if that is present in the request then it doesn't force non-https. Kinda confusing if you don't have a mod_rewrite cheatsheet.

RewriteCond %{THE_REQUEST} ^$ [OR]
RewriteCond %{REQUEST_URI} ^/(wp-admin|wp-login\.php).*$ [NC,OR]
RewriteCond %{HTTP_COOKIE} ^.*wp_li_sadfsdfasdf11b361cdsdfasdfasd=.*$ [NC]
RewriteRule .* - [S=1]
 
RewriteCond %{HTTPS} =on [OR]
RewriteCond %{HTTP_HOST} !^www\.askapache\.com$ [NC]
RewriteRule .* http://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]
 
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(wp-admin/.*|wp-login\.php.*)\ HTTP/ [NC]
RewriteCond %{HTTPS} !=on
RewriteRule .* https://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]

File System Permissions

You can get a basic and solid intro on file permissions by reading: Changing File Permissions, or you can check out some of my file permission research.

/** The permissions as octal number, usually 0644 for files, 0755 for dirs.
 *  http://codex.wordpress.org/Changing_File_Permissions
 *  if ( !$wp_filesystem->mkdir($remote_destination, FS_CHMOD_DIR) )
 */
!defined('FS_CHMOD_DIR') && define('FS_CHMOD_DIR', (0755 & ~ umask()));
!defined('FS_CHMOD_FILE') && define('FS_CHMOD_FILE', (0644 & ~ umask()));
/**#@-*/
 
/** Define the timeouts for the connections. Only available after the construct is called to allow for per-transport overriding of the default. */
//stream_set_timeout( $stream, FS_TIMEOUT );
//!defined('FS_TIMEOUT') && define('FS_TIMEOUT', 30);
 
//$this->link = @ftp_connect($this->options['hostname'], $this->options['port'], FS_CONNECT_TIMEOUT);
//!defined('FS_CONNECT_TIMEOUT') && define('FS_CONNECT_TIMEOUT', 30);
 
// function get_filesystem_method($args = array(), $context = false) {
//  $method = defined('FS_METHOD') ? FS_METHOD : false; //Please ensure that this is either 'direct', 'ssh', 'ftpext' or 'ftpsockets'
//!defined('FS_METHOD') && define('FS_METHOD', 'direct');
 
/** These methods for the WordPress core, plugin, and theme upgrades try to determine the WordPress path, as reported by PHP, but symlink trickery can sometimes
 * 'muck this up' so if you know the paths to the various folders on the server, as seen via your FTP user, you can manually define them in the wp-config.php file.
 * FS_METHOD forces the filesystem method. It should only be "direct", "ssh", "ftpext", or "ftpsockets".
 * FTP_BASE is the full path to the "base" folder of the WordPress installation.
 * FTP_CONTENT_DIR is the full path to the wp-content folder of the WordPress installation.
 * FTP_PLUGIN_DIR is the full path to the plugins folder of the WordPress installation.
 * FTP_PUBKEY is the full path to your SSH public key.
 * FTP_PRIKEY is the full path to your SSH private key.
 * FTP_USER is either user FTP or SSH username. Most likely these are the same, but use the appropriate one for the type of update you wish to do.
 * FTP_PASS is the password for the username entered for FTP_USER. If you are using SSH public key authentication this can be omitted.
 * FTP_HOST is the hostname:port combination for your SSH/FTP server. The standard FTP port is 21 and the standard SSH port is 22.
 */
//define('FS_METHOD', 'ftpext');
//define('FTP_BASE', '/path/to/wordpress/');
//define('FTP_CONTENT_DIR', '/path/to/wordpress/wp-content/');
//define('FTP_PLUGIN_DIR ', '/path/to/wordpress/wp-content/plugins/');
//define('FTP_PUBKEY', '/home/username/.ssh/id_rsa.pub');
//define('FTP_PRIKEY', '/home/username/.ssh/id_rsa');
//define('FTP_USER', 'username');
//define('FTP_PASS', 'password');
//define('FTP_HOST', 'ftp.example.org:21');
 
/**
 * Block requests through the proxy.
 *
 * Those who are behind a proxy and want to prevent access to certain hosts may do so. This will
 * prevent plugins from working and core functionality, if you don't include api.wordpress.org.
 *
 * You block external URL requests by defining WP_HTTP_BLOCK_EXTERNAL in your wp-config.php file
 * and this will only allow localhost and your blog to make requests.
 * The constant WP_ACCESSIBLE_HOSTS will allow additional hosts to go through for requests. The format of the
 * WP_ACCESSIBLE_HOSTS constant is a comma separated list of hostnames to allow.
 *
 * @since 2.8.0
 * @link http://core.trac.wordpress.org/ticket/8927 Allow preventing external requests.
/** @since 2.9  */
//!defined('WP_HTTP_BLOCK_EXTERNAL') && define( 'WP_HTTP_BLOCK_EXTERNAL', false );
 
/*
 * The constant WP_ACCESSIBLE_HOSTS will allow additional hosts to go through for requests. The format of the
 * WP_ACCESSIBLE_HOSTS constant is a comma separated list of hostnames to allow.
 *
 * @since 2.8.0
 * @link http://core.trac.wordpress.org/ticket/8927 Allow preventing external requests.
 * $accessible_hosts = preg_split('|,\s*|', WP_ACCESSIBLE_HOSTS);
 * return !in_array( $check['host'], $accessible_hosts ); //Inverse logic, If its in the array, then we can't access it.
 */
//!defined('WP_ACCESSIBLE_HOSTS') && define( 'WP_ACCESSIBLE_HOSTS', 'askapache.com,askapache.org' );

Cookies!

There's always a little comfort in having non-default cookies for security (against auto-bots), and using shorter names also means smaller HTTP Packets.

The $cookie_hash is my hack to get around the fact that COOKIEHASH isn't definable in wp-config.

/**#@+
 * COOKIES
 * Used to guarantee unique hash cookies @since 1.5 */
$cookie_hash=md5(WP_SITEURL);
 
/** Set a cookie now to see if they are supported by the browser.
 * setcookie(TEST_COOKIE, 'WP Cookie check', 0, COOKIEPATH, COOKIE_DOMAIN);
 * @since 2.3.0 */
!defined('TEST_COOKIE') && define('TEST_COOKIE', 'wp_tc');
 
/* @since 2.6.0 */
!defined('LOGGED_IN_COOKIE') && define('LOGGED_IN_COOKIE', 'wp_li_' . $cookie_hash);
 
/* @since 2.6.0 */
!defined('SECURE_AUTH_COOKIE') && define('SECURE_AUTH_COOKIE', 'wp_sa_' . $cookie_hash);
 
/* @since 2.5.0 */
!defined('AUTH_COOKIE') && define('AUTH_COOKIE', 'wp_a_' . $cookie_hash);
 
/* @since 2.0.0 */
!defined('PASS_COOKIE') && define('PASS_COOKIE', 'wp_p_' . $cookie_hash);
 
/* @since 2.0.0 */
!defined('USER_COOKIE') && define('USER_COOKIE', 'wp_u_' . $cookie_hash);
 
/* ok unset this var, its not needed as COOKIEHASH will have this value, but is not definable in wp-config.php */
unset($cookie_hash);
 
/** @since 1.2.0 */
!defined('COOKIEPATH') && define('COOKIEPATH', preg_replace('|https?://[^/]+|i', '', WP_HOME . '/' ) );
 
/** @since 1.5.0 */
!defined('SITECOOKIEPATH') && define('SITECOOKIEPATH', preg_replace('|https?://[^/]+|i', '', WP_SITEURL . '/' ) );
 
/** @since 2.6.0 */
!defined('ADMIN_COOKIE_PATH') && define( 'ADMIN_COOKIE_PATH', SITECOOKIEPATH . 'wp-admin' );
 
/** @since 2.6.0 */
!defined('PLUGINS_COOKIE_PATH') && define( 'PLUGINS_COOKIE_PATH', preg_replace('|https?://[^/]+|i', '', WP_PLUGIN_URL)  );
 
/** @since 2.0.0 */
!defined('COOKIE_DOMAIN') && define('COOKIE_DOMAIN', $_SERVER['SERVER_NAME']);

/**
  * The WP_CACHE setting, if true, includes the wp-content/advanced-cache.php script, when executing wp-settings.php.
  * For an advanced caching plugin to use, static because you would only want one
  * if ( defined('WP_CACHE') )@include WP_CONTENT_DIR . '/advanced-cache.php';
  */
!defined('WP_CACHE') && define('WP_CACHE', true);
 
/** WordPress Localized Language, defaults to en_US.
 *
 * Change this to localize WordPress.  A corresponding MO file for the chosen
 * language must be installed to wp-content/languages. For example, install
 * de.mo to wp-content/languages and set WPLANG to 'de' to enable German
 * language support. */
!defined('WPLANG') && define ('WPLANG', 'en_US');
 
/** Stores the location of the language directory. First looks for language folder in WP_CONTENT_DIR
 *   and uses that folder if it exists. Or it uses the "languages" folder in WPINC. @since 2.1.0 */
//!defined('WP_LANG_DIR') && define('WP_LANG_DIR', ABSPATH . WPINC . '/languages');
 
/** LANGDIR defines what directory the WPLANG .mo file resides. If LANGDIR is not defined WordPress looks first to wp-content/languages and then wp-includes/languages for the .mo defined by WPLANG file.  Old static relative path maintained for limited backwards compatibility - won't work in some cases*/
//!defined('LANGDIR') && define('LANGDIR', 'wp-content/languages');
 
/** Stores the location of the WordPress directory of functions, classes, and core content. @since 1.0.0 */
//!defined('WPINC') && define('WPINC', 'wp-includes');

WPMU Stuff

I personally don't use.

/** Allows for the mu-plugins directory to be moved from the default location. @since 2.8.0 */
//!defined('WPMU_PLUGIN_DIR') && define( 'WPMU_PLUGIN_DIR', WP_CONTENT_DIR . '/mu-plugins' ); // full path, no trailing slash
 
/** Allows for the mu-plugins directory to be moved from the default location. @since 2.8.0 */
//!defined('WPMU_PLUGIN_URL') && define( 'WPMU_PLUGIN_URL', WP_CONTENT_URL . '/mu-plugins' ); // full url, no trailing slash
 
/** Allows for the mu-plugins directory to be moved from the default location. @since 2.8.0 */
//!defined( 'MUPLUGINDIR' ) && define( 'MUPLUGINDIR', 'wp-content/mu-plugins' ); // Relative to ABSPATH.  For back compat.

WordPress Database

This is usually the only thing I have to manually edit when creating a new site, unless I just use the same DB and modify the $table_prefix, (farther down). I run everything I possibly can in UTF-8, but if you don't already know alot about character sets, wow it is one of the most confusing things so you may want to save learning about that topic for another day. Otherwise the following are helpful (and show how confusing character sets are!)

• Character Sets and Collations MySQL Support
• Converting Database Character Sets
• UTF-8 character sets (UTF-8)

If you ever setup WP to use the builtin membership features, make sure you learn about the CUSTOM_USER_TABLE and CUSTOM_USER_META_TABLE constants, I've found them very helpful.

/**#@+
 * MySQL settings
 */
/** The name of the database for WordPress */
define('DB_NAME', 'askapachewpblog75');
 
/** The username to access the database */
define('DB_USER', 'askapache245d');
 
/** The password for the username to access the database */
define('DB_PASSWORD', 'asdfklj2340');
 
/** The hostname to connect to the database at */
define('DB_HOST', 'mysql.askapache.com');
 
/** The charset of the database */
define('DB_CHARSET', 'utf8');
 
/** The collation of the database */
define('DB_COLLATE', 'utf8_general_ci');

$table_prefix

The $table_prefix is the value placed in the front of your database tables. Change the value if you want to use something other than wp_ for your database prefix. Typically this is changed if you are installing multiple WordPress blogs in the same database, and also for enhanced security.

Its a safe and good idea to change this value pre-installation to add more security to your WordPress blog. Exploits attempted against your WordPress blog by malicious crackers often are built with the premise that your blog uses the prefix wp_, by changing the value you mitigate some attack vectors.

/**
 * WordPress Database Table prefix.
 *
 * You can have multiple installations in one database if you give each a unique
 * prefix. Only numbers, letters, and underscores please!
 */
$table_prefix  = 'ar15_';
 
/** CUSTOM_USER_TABLE and CUSTOM_USER_META_TABLE are used to designated that the user and usermeta tables normally utilized by WordPress are not used, instead these values/tables are used to store your user information. */
//!defined('CUSTOM_USER_TABLE') && define('CUSTOM_USER_TABLE', $table_prefix . 'my_users');
//!defined('CUSTOM_USER_META_TABLE') && define('CUSTOM_USER_META_TABLE', $table_prefix . 'my_usermeta');

Setup PHP Ini Settings

/** Turns the output of errors on or off, you really never want this on, you should only view errors by reading the log file. */
ini_set('display_errors', WP_DEBUG_DISPLAY);
 
/** Tells whether script error messages should be logged to the server's error log or error_log. */
ini_set('log_errors', 'On');
 
/** http://us.php.net/manual/en/timezones.php */
ini_set('date.timezone', 'America/Indianapolis');
 
/** Where to log php errors */
ini_set('error_log', ASKAPACHE_ROOT . '/logs/php_error.log');
 
/** Set the memory limit, otherwise defaults to '32M' */
ini_set('memory_limit', WP_MEMORY_LIMIT);

Sessions are slow

So I only use sessions when I have a specific use... In this case I need sessions only when one of the tools in the /online-tools/ directory is being used. And that is for the captcha image. In the future I won't ever use sessions.

if(preg_match( '#^/online-tools/#',$_SERVER['REQUEST_URI'])) session_start();

Include Custom Files

Sure you could use the my-hacks.php that WP allows, or you can just stick your functions in your TEMPLATEPATH/functions.php file, but they are executed only after the wp-settings.php file, which may be too late for your file.

In the past I've also used the auto_prepend_file settings to run my script before anything (index.php) but I ran into some issues on different hosts, and it wasn't as portable.

This is useful because you can have a file with globally available functions that you can use in non-WP areas as well as WP areas. I am moving away from this more and more as I learn more about classes and build plugins instead for portability.

include_once ASKAPACHE_ROOT . '/includes/myfunctions.inc';
 
/** Sets up WordPress vars and included files. */
require_once(ABSPATH . 'wp-settings.php');
?>

Some Useful PHP

I am constantly trying to make my sites and code more portable, so I am using plugins alot more to accomplish things that I use to do with separate php. Here are some examples of minimal php.

add_filter("the_generator", create_function('$a','return "";'));
add_filter('the_content', create_function('$a', 'return ((is_feed())? $a."<p><a href=\"".get_permalink()."\">".get_the_title()."</a> originally appeared on ".get_bloginfo("name").".</p>" : $a);'), 99999);
add_filter('excerpt_length', create_function('$a', 'return 300;'),99);
add_filter('excerpt_more', create_function('$a', 'return "&hellip;";'),99);
add_action( 'wp_head', create_function('$a','echo "<link rel=\"pingback\" href=\"'.get_bloginfo('pingback_url').'\" />\n";'), 95 );
add_action( 'wp_head', create_function('$a','echo "<link rel=\"schema.rss\" href=\"http://purl.org/rss/1.0/\" />\n";'), 96 );
add_action( 'wp_head', create_function('$a','echo "<link rel=\"schema.rel\" href=\"http://purl.org/vocab/relationship/\" />\n";'), 97 );
add_action( 'wp_head', create_function('$a','echo "<link rel=\"meta\" type=\"application/rdf+xml\" href=\"/foaf.rdf\" />\n";'), 98 );
add_action( 'wp_head', create_function('$a','echo "<link href=\"/favicon.ico\" rel=\"shortcut icon\" type=\"image/x-icon\" />\n";'), 99 );

Debugging Note

If you read this far than you probably know how important debugging is, but I sometimes like to stick the best tips deep in my articles to make sure only YOU find it. GRTFM isn't used on this site, it's mostly a requirement because my writing can get pretty bad.. The point, debugging is more than a crucial requirement if you want to do anything cool. Don't worry I got you.. check my AskApache Debug Viewer Plugin from the official WP site. It's pretty close to providing as verbose amount of information that I could possibly figure out how to get out of php, probably more than you have ever seen at least, I focused on quantity. I use it all the time on new installs as there is no setup required and it tells me advanced information about the setup of the server, hacker code for sure.

Here's a quick function to see set global vars, I just think this is interesting code.

function askapache_global_debug(){
  global $_GET,$_POST,$_COOKIE,$_SESSION,$_ENV,$_FILES,$_SERVER,$_REQUEST,$HTTP_POST_FILES,$HTTP_POST_VARS,$HTTP_SERVER_VARS,$HTTP_RAW_POST_DATA,$HTTP_GET_VARS,$HTTP_COOKIE_VARS,$HTTP_ENV_VARS;
  $gv=create_function('$n','global $$n; ob_start(); if ( is_array($$n) && sizeof($$n)>0 && print("[{$n}]\n") ) print_r($$n);return ob_get_clean();');
  foreach (array('_GET','_POST','_COOKIE','_SESSION','_ENV','_FILES','_SERVER','_REQUEST','HTTP_POST_FILES','HTTP_POST_VARS','HTTP_SERVER_VARS','HTTP_RAW_POST_DATA','HTTP_GET_VARS','HTTP_COOKIE_VARS','HTTP_ENV_VARS') as $k)echo $gv($k);
  print_r(get_defined_constants());
}

Also check the WordPress Codex page: Editing wp-config.php and Perishable Press's: Stupid WordPress Tricks

Advanced WordPress wp-config.php Tweaks originally appeared on AskApache.com

Because backups contain all your sensitive information, its smart to encrypt any sql backups.. and while we're at it, also encrypt any site backups.

This simple shell-script is a useful and easy way to securely backup your wordpress and/or phpBB site files and database without confusing you. Just generate a GPG key once, enter in 3 settings once, and from then on it runs without any user-input whenever you want.

What it Does

When run, this script asks you for the location of your websites document root and the location of your wp-config.php or config.php file. It also asks you for your encryption UID. Then this script saves those settings in a file called .sbackup so that the next time you run the script it will run without having to re-enter that information, making it nice for cronjobs or quick and easy on-demand backups. Another cool feature that I added is this script automatically parses your wp-config.php file for the mysql database name, user, host, and password, meaning you don't have to compromise your security or take the time to type those settings in manually.

What is Backed Up

This script creates a tarred and gzipped archive of your entire document root in the folder ~/backups/domain.com/domain.com-date.tgz and also creates a backup of your WordPress database and phpBB database in a format that is ideal for restoring from. Both of these files are then encrypted using your GPG key and can then be safely downloaded as a password and key is required to decrypt them.

Generating a GPG Key

If you don't already have one setup for your shell account run this command remembering the uid which you will enter in the shell script.

gpg --gen-key

Decrypting Files

gpg -r UID --output FILENAME.tgz --decrypt FILENAME.tgz.asc

The Shell Script

site-backup.sh

#!/bin/bash
# SiteBack Version 3.3, 2008-12-17
# GNU Free Documentation License 1.2
# 12-17-08 - AskApache (www.askapache.com)
umask 022
 
### SHELL OPTIONS
set +o noclobber # allowed to clobber files
set +o noglob # globbing on
set +o xtrace # change to - to enable tracing
set +o verbose # change to - to enable verbose debugging
set -e # abort on first error
shopt -s extglob
 
###########################################################################--=--=--=--=--=--=--=--=--=--=--#
###
### SETTINGS
###
###########################################################################==-==-==-==-==-==-==-==-==-==-==#
 
DT=$(date +%x); DT=${DT//\/}
DTX=$(date +%x-%H%M); DTX=${DTX//\/}
BDIR=${HOME}/backups
RUN_FILE=${BDIR}/$$.bk.log
MY_CONFIG=".sbackup"
DOMAIN=;DB_NAME=;DB_USER=;DB_PASSWORD=;DB_HOST=;APP_CONFIG=;SQL_DEST=;ARC_DEST=;ENCRYPT_USER=
E_SUCCESS=0;E_YN=0;E_YES=251;E_NO=250;E_RETURN=65;C0=;C1=;C2=;C3=;C4=;C5=;C5=;C7=
 
###########################################################################--=--=--=--=--=--=--=--=--=--=--#
###
### FUNCTIONS
###
###########################################################################==-==-==-==-==-==-==-==-==-==-==#
 
#--=--=--=--=--=--=--=--=--=--=--#
# script_title
#==-==-==-==-==-==-==-==-==-==-==#
function script_title(){
 local e="\033["
 local l=' ___________________________________________________________________ '
 
 # SET WINDOW TITLE AND COLORS IF CLIENT CAPABLE
 case $TERM in xterm*|vt*|ansi|rxvt|gnome*)
 C0="${e}0m";C1="${e}1;30m";C2="${e}1;32m";C3="${e}0;32m";C4="${e}1;37m";C5="${e}1;35m";C6="${e}30;42m"
 esac
 
 echo -e "\n${C0}$l${C1}"
 echo -e "|             ${C2}___       __    ___                 __${C1}                |"
 echo -e "|            ${C2}/ _ | ___ / /__ / _ | ___  ___ _____/ /  ___${C1}           |"
 echo -e "|           ${C2}/ __ |(_-</  '_// __ |/ _ \/ _ \`/ __/ _ \/ -_)${C1}          |"
 echo -e "|          ${C3}/_/ |_/___/_/\_\/_/ |_/ .__/\_,_/\__/_//_/\__/${C1}           |"
 echo -e "|                               ${C3}/_/${C1}                                 |"
 echo -e "|                                                                   |"
 echo -e "|       ${C1}+--${C0} SITE BACKUP SCRIPT Version 3.3${C1}                          |"
 echo -e "${C0}$l\n\n"
}
 
#--=--=--=--=--=--=--=--=--=--=--#
# pm
#==-==-==-==-==-==-==-==-==-==-==#
function pm(){
 START=$(date +%s) && touch ${RUN_FILE}
 case "${2:-title}" in
  "title") echo -en "\n\n${C2}>>> ${C4}${1} ${C0} \n\n"; ;;
   "info") echo -e "${C5}=> ${C4}${1} ${C0}"; ;;
   "item") echo -e "${C4}-- ${C0}${1} "; ;;
 esac
}
 
#--=--=--=--=--=--=--=--=--=--=--#
# yes_no
#==-==-==-==-==-==-==-==-==-==-==#
function yes_no(){
 local ans
 echo -en "${1} [y/n] " ; read -n 1 ans
 case "$ans" in
  n|N) E_YN=$E_NO ;;
  y|Y) E_YN=$E_YES ;;
 esac
}
 
#--=--=--=--=--=--=--=--=--=--=--#
# do_sleep
#==-==-==-==-==-==-==-==-==-==-==#
function do_sleep (){
 local END DIFF
 echo -en "${C5}${3:-.}"; while [ -r "$RUN_FILE" ]; do sleep ${2:-3}; echo -en "${3:-.}"; done;
 echo -e "${C0}"; sleep 1; END=$(date +%s);DIFF=$(( $END - $START ))
 echo -e "\n${C6} [T: ${SECONDS}] COMPLETED IN ${DIFF} SEC ${C0} \n\n"; sleep 1;
 return 0;
}
 
#--=--=--=--=--=--=--=--=--=--=--#
# get_settings
#==-==-==-==-==-==-==-==-==-==-==#
function get_settings(){
 local cha HOSTED_SITES G GG
 clear; script_title
 
 if [[ -r "$MY_CONFIG" ]]; then
 
  OIFS=$IFS; while IFS=: read DOMAIN DOMAINROOT APP_CONFIG ENCRYPT_USER; do
   DOMAIN=${DOMAIN};
   DOMAINROOT=${DOMAINROOT};
   APP_CONFIG=${APP_CONFIG};
   ENCRYPT_USER=${ENCRYPT_USER};
   #E_YN=$E_YES;
   break
  done <${MY_CONFIG};
  IFS=$OIFS
 
 else
 
  gpg --list-keys|grep uid.*|awk '{print $2}'
  echo -en "\n What userid to use for encryption?  ";
  read -e ENCRYPT_USER; echo
 
  echo -en "\n What domain would you like to backup?  "; read -e DOMAIN; echo
 
  echo $PWD
  until [ -d "$DOMAINROOT" ]; do echo -en "\n Folder where config file is located?  ";
  read -e DOMAINROOT; echo; done
 
  [[ -r "$DOMAINROOT/config.php" ]] && APP_CONFIG=$DOMAINROOT/config.php && DOT=PHP
  [[ -r "$DOMAINROOT/wp-config.php" ]] && APP_CONFIG=$DOMAINROOT/wp-config.php && DOT=WP
 
  echo $PWD
  until [[ -r "$APP_CONFIG" ]]; do echo -en "\n Where is the applications config file?  "; read -e APP_CONFIG; echo; done
 
 fi
 
  [[ -r "$DOMAINROOT/config.php" ]] && APP_CONFIG=$DOMAINROOT/config.php && DOT=PHP
  [[ -r "$DOMAINROOT/wp-config.php" ]] && APP_CONFIG=$DOMAINROOT/wp-config.php && DOT=WP
 
  ### For phpBB
  if [[ "${DOT}" == "PHP" ]]; then
    GG=$(sed -e '/$db\(n\|u\|pa\|h\)/!d' -e "s/$db_\(name\|user\|passwd\|host\)\ =\ '\([^']*\).*\$/\1='\2';/g" -e 's/$db/DB_/g' ${APP_CONFIG});
    G=$(echo ${GG}|sed -e 's/DB_name/DB_NAME/g' -e 's/DB_user/DB_USER/g' -e 's/DB_passwd/DB_PASSWORD/g' -e 's/DB_host/DB_HOST/g');
  else
    G=$(sed -e "/define('DB_\(NAME\|USER\|PASSWORD\|HOST\)/!d" -e "s/[^']*'DB_\(NAME\|USER\|PASSWORD\|HOST\)'[^']*'\([^']*\)'.*$/DB_\1='\2';/g" ${APP_CONFIG})
  fi
  eval $G;
 
 mkdir -p ${BDIR}/${DOMAIN}
 SQL_DEST=${BDIR}/${DOMAIN}/${DOMAIN}-${DT}.sql;
 [[ -r "${SQL_DEST}.asc" ]] && SQL_DEST=${BDIR}/${DOMAIN}/${DOMAIN}-${DTX}.sql
 
 ARC_DEST=${BDIR}/${DOMAIN}/${DOMAIN}-${DT}.tgz;
 [[ -r "${ARC_DEST}.asc" ]] && ARC_DEST=${BDIR}/${DOMAIN}/${DOMAIN}-${DTX}.tgz
 
 if [[ "$E_YN" != "$E_YES" ]]; then
  for a in "DOMAIN" "DOMAINROOT" "APP_CONFIG" "ENCRYPT_USER" "DB_NAME" "DB_USER" "DB_PASSWORD" "DB_HOST"; do echo -e "${a}: ${!a}"; done
  echo; yes_no "ARE THESE SETTINGS CORRECT"
 fi
 
 while [[ "$E_YN" != "$E_YES" ]]; do
  for a in "DOMAIN" "DOMAINROOT" "APP_CONFIG" "ENCRYPT_USER" "DB_NAME" "DB_USER" "DB_PASSWORD" "DB_HOST"; do
   echo -en "\n (Enter for Default: ${!a} )\n ${a}:> "
   read -e cha; echo; [[ ${#cha} -gt 2 ]] && eval "$a"=$cha
  done
  yes_no "ARE THESE SETTINGS CORRECT"
 done
 
 echo -e "${DOMAIN}:${DOMAINROOT}:${APP_CONFIG}:${ENCRYPT_USER}" > $MY_CONFIG
}
 
#--=--=--=--=--=--=--=--=--=--=--#
# exit_cleanup
#==-==-==-==-==-==-==-==-==-==-==#
function exit_cleanup(){
 cd $OLDPWD
 [[ -r "${SQL_DEST}" ]] && rm ${SQL_DEST}
 [[ -r "${ARC_DEST}" ]] && rm ${ARC_DEST}
}
 
############################################################################################################
###
### MAIN CODE
###
############################################################################################################
 
#=# CATCH SCRIPT KILLED BY USER
trap exit_cleanup SIGHUP SIGINT SIGTERM
 
#=# MAKE MAIN SCRIPT NICE
renice 19 -p $$ &>/dev/null
 
cd `dirname $0`
 
get_settings
 
pm "CREATING SQL BACKUP"
mysqldump --opt -u${DB_USER} -p${DB_PASSWORD} -h ${DB_HOST} -r ${SQL_DEST} --add-drop-table ${DB_NAME} 1>&2 &>/dev/null && sleep 2 1>&2 &>/dev/null && rm ${RUN_FILE} 2>&1&
do_sleep 1 1 ":"
 
pm "ENCRYPTING SQL BACKUP"
gpg --armor --recipient ${ENCRYPT_USER} --output ${SQL_DEST}.asc --encrypt ${SQL_DEST} 1>&2 &>/dev/null && sleep 2 1>&2 &>/dev/null && rm ${RUN_FILE} 2>&1&
do_sleep 1 1 ":"; rm ${SQL_DEST}
 
pm "CREATING ARCHIVE BACKUP"
tar -czf ${ARC_DEST} . 1>&2 &>/dev/null && rm ${RUN_FILE} 2>&1&
do_sleep 1 5 ":"
 
pm "ENCRYPTING ARCHIVE BACKUP"
gpg --armor --recipient ${ENCRYPT_USER} --output ${ARC_DEST}.asc --encrypt ${ARC_DEST} 1>&2 &>/dev/null && rm ${RUN_FILE} 2>&1&
do_sleep 1 1 ":"; rm ${ARC_DEST}
 
echo -e "${C1} __________________________________________________________________________ "
echo -e "|                                                                          |"
echo -e "|                 ${C4} COMPLETED SUCCESSFULLY ${C1}                                 |"
echo -e "${C1} __________________________________________________________________________ ${C0} \n\n"
 
cd $OLDPWD
 
exit $?

Encrypted WordPress / phpBB Backups originally appeared on AskApache.com