update-motd man page on ElementaryOS

Man page or keyword search:  
man Server   4994 pages
apropos Keyword Search (all sections)
Output format
ElementaryOS logo
[printable version]

update-motd(5)							update-motd(5)

NAME
       update-motd - dynamic MOTD generation

SYNOPSIS
       /etc/update-motd.d/*

DESCRIPTION
       UNIX/Linux system adminstrators often communicate important information
       to console and remote users by maintaining text in the file  /etc/motd,
       which  is  displayed  by	 the  pam_motd(8)  module on interactive shell
       logins.

       Traditionally, this file is static text,	 typically  installed  by  the
       distribution  and  only	updated on release upgrades, or overwritten by
       the local administrator with pertinent information.

       Ubuntu introduced the update-motd framework, by which  the  motd(5)  is
       dynamically assembled from a collection of scripts at login.

       Executable  scripts in /etc/update-motd.d/* are executed by pam_motd(8)
       as the root user at each login, and this information is concatenated in
       /var/run/motd.  The order of script execution is determined by the run-
       parts(8) --lsbsysinit option (basically alphabetical order, with a  few
       caveats).

       On   Ubuntu   systems,  /etc/motd  is  typically	 a  symbolic  link  to
       /var/run/motd.

BEST PRACTICES
       MOTD fragments must be scripts  in  /etc/update-motd.d,	must  be  exe‐
       cutable, and must emit information on standard out.

       Scripts	should be named named NN-xxxxxx where NN is a two digit number
       indicating their position in the MOTD, and  xxxxxx  is  an  appropriate
       name for the script.

       Scripts	must  not  have	 filename  extensions, per run-parts(8) --lsb‐
       sysinit instructions.

       Packages should add scripts directly  into  /etc/update-motd.d,	rather
       than  symlinks to other scripts, such that administrators can modify or
       remove these scripts and upgrades will  not  wipe  the  local  changes.
       Consider	 using	a  simple  shell  script that simply calls exec on the
       external utility.

       Long running operations (such as network calls) or  resource  intensive
       scripts	should	cache  output,	and  only  update that output if it is
       deemed expired.	For instance:

	 /etc/update-motd.d/50-news
	 #!/bin/sh
	 out=/var/run/foo
	 script="w3m -dump http://news.google.com/"
	 if [ -f "$out" ]; then
	   # Output exists, print it
	   echo
	   cat "$out"
	   # See if it's expired, and background update
	   lastrun=$(stat -c %Y "$out") || lastrun=0
	   expiration=$(expr $lastrun + 86400)
	   if [ $(date +%s) -ge $expiration ]; then
	     $script > "$out" &
	   fi
	 else
	   # No cache at all, so update in the background
	   $script > "$out" &
	 fi

       Scripts should emit a blank line before output, and end with a  newline
       character.  For instance:

	 /etc/update-motd/05-lsb-release
	 #!/bin/sh
	 echo
	 lsb-release -a


FILES
       /etc/motd, /var/run/motd, /etc/update-motd.d

SEE ALSO
       motd(5), pam_motd(8), run-parts(8)

AUTHOR
       This  manpage and the update-motd framework was written by Dustin Kirk‐
       land <kirkland@canonical.com> for Ubuntu systems (but may  be  used  by
       others).	  Permission is granted to copy, distribute and/or modify this
       document under the terms of the GNU General Public License,  Version  3
       published by the Free Software Foundation.

       On  Debian systems, the complete text of the GNU General Public License
       can be found in /usr/share/common-licenses/GPL.

update-motd			 13 April 2010			update-motd(5)
[top]

List of man pages available for ElementaryOS

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net