EnvironmentalVariables

In UNIX and Windows many of the commands run have variables that are parsed from a users environment. These can be set in many ways but we will cover the most popular tcsh and bash.

PATH

The most common variable is the PATH variable, this will add additional paths to search for programs to be run from the command line. You can see your PATH variable by using the built in echo command in the shell. When printing out environment variables you will need to prefix the variable with the $ sign.

# echo $PATH
/usr/kerberos/bin:/opt/condor-7.0.5/bin:/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin

In almost all cases you will want to append to either the beginning or end of your PATH variable and not replace it fully as this will most likely decrease the functionality of your shell. For example if you wanted to add the path /opt/UMtorque/bin to the end of your PATH then you could do the following,

tcsh/csh

setenv PATH ${PATH}:/opt/UMtorque/bin

bash/sh

export PATH=${PATH}:/opt/UMtorque/bin

These can be either typed into your shell directly or added to your shells initialization files so every time you spawn a shell it will get this new PATH.