How to set, print, or list environment variables

from http://how-to.wikia.com/wiki/How_to_set,_print,_or_list_environment_variables

 

To set a environment variables

 

• For bourne shells sh, ksh, bash
  • execute: VARNAME="value"; export VARNAME

• For c shellscsh. tcsh
  • execute: setenv VARNAME "value"

    Edit the ~/.bashrc to set the enviromental variables permanently.

Display environment variables

display/print/list environment variables

• To list all environment variables
  • Execute: printenv

• To print a specific environment variable
  • Execute: echo $Env_Var_Name
    • Example: echo $PATH

Common environment variables

• MANPATH=/usr/local/share/man:/usr/share/man
• HOSTNAME=localhost
• SHELL=/bin/bash
• TERM=xterm
• XTERM_SHELL=/bin/bash
• PATH=/usr/java/j2sdk1.4.2_01/bin:/bin:/sbin:/usr/sbin:/usr/bin:/usr/local/bin/::/usr/local/sbin
• EDITOR=/bin/nano
• BASH_ENV=/home/zymos/.bashrc
• INFOPATH=/usr/share/info:/usr/share/binutils-data/i686-pc-linux-gnu/2.16.1/info:/usr/share/gcc-data/i686-pc-linux-gnu/3.4.5/info
• DISPLAY=:0.0
• PKG_CONFIG_PATH=/usr/X11R6/lib/pkgconfig:/usr/local/lib/pkgconfig:/usr/qt/3/lib/

 

And the Set built-in command can be used to dump out all the existing variables.