Setting Environment Variables

Setting Environment Variables

Environment variables are used to store information in a form that is accessible to commands within the shell and other applications that are spawned from the shell. You can obtain a list of all environment variables that have been set in a shell by using the following command:

 bash-2.03$ set BASH=/usr/local/bin/bash BASH_VERSINFO=([0]="2" [1]="03" [2]="0" [3]="1" [4]="release" \   [5]="i386-pc-solaris2.9") BASH_VERSION='2.03.0(1)-release' COLUMNS=80 DIRSTACK=() DISPLAY=cassowary:0.0 EDITOR=/usr/bin/vi ENV=/.kshrc EUID=0 GROUPS=() HELPPATH=/usr/openwin/lib/locale:/usr/openwin/lib/help HISTFILE=/.sh_history HISTFILESIZE=500 HISTSIZE=500 HOME=/ HOSTNAME=cassowary HOSTTYPE=i386 IFS=' ' LANG=en_AU LC_COLLATE=en_AU LC_CTYPE=en_AU LC_MESSAGES=C LC_MONETARY=en_AU LC_NUMERIC=en_AU LC_TIME=en_AU LD_LIBRARY_PATH=/usr/local/lib:/usr/openwin/lib:/usr/dt/lib LINES=24 LOGNAME=root MACHTYPE=i386-pc-solaris2.9 MAIL=/var/mail/root MAILCHECK=60 MANPATH=/usr/dt/man:/usr/man:/usr/openwin/share/man OPENWINHOME=/usr/openwin OPTERR=1 OPTIND=1 OSTYPE=solaris2.9 PATH=/usr/sbin:/usr/bin:/bin:/usr/ucb:/usr/local/bin:/usr/ccs/bin PIPESTATUS=([0]="1") PPID=1584 PS1='\s-\v$ ' PS2='>> ' PS4='+ ' PWD=/etc SESSION_SVR=tango SHELL=/bin/ksh SHLVL=1 TERM=dtterm TERMINAL_EMULATOR=dtterm TZ=Australia/NSW UID=0 USER=root WINDOWID=58720265 

Although this seems to be a lot of shell variables, the most significant ones include the following:

BASH

The path to the shell on the file system

COLUMNS

The column s width for the terminal

DISPLAY

The display variable that is used for X11 graphics

HOME

The default home directory for the user

HOSTNAME

The hostname of the current system

LD_LIBRARY_PATH

The path to system and user libraries

LOGNAME

The username of the shell owner

MANPATH

The path to the system manuals

NNTPSERVER

The hostname of the NNTP server

PATH

The path that is searched to find applications where no absolute path is specified on the command line

PPID

The parent process ID

TERM

The terminal type (usually VT100)

UID

The user ID

WINDOWMANAGER

The name of the X11 window manager

The values of all shell variables can be set on the command line by using the export command. For example, if you wanted to set the terminal type to VT220, you would use this command:

 $ TERM=vt220; export TERM 
 
 
   


Sun Certified Solaris 9.0 System and Network Administrator
Sun Certified Solaris(tm) 9 System and Network Administrator All-in-One Exam Guide
ISBN: 0072225300
EAN: 2147483647
Year: 2003
Pages: 265
Authors: Paul Watters

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