Display or print UNIX / Linux path ~ $PATH variable

In UNIX / Linux file systems, the human-readable address of a resource is defined by PATH. On Unix / Linux like operating systems, (as well as on DOS / Windows and its descendants), PATH is an environment variable listing a set of paths to directories where executables may be found.
Display current PATH

Use echo command:
$ echo $PATH
Output:

/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/bin/X11:/usr/games

Modify current PATH

Use export command to add /opt/games to PATH, enter:
export PATH=$PATH:/opt/games

To format your PATH variable for easy viewing, add following code to your bash startup file (such as ~/.bashrc or ~/.bash_profile) :

function path(){
old=$IFS
IFS=:
printf "%s\n" $PATH
IFS=$old
}

(Function credit: usenet archive)

Now just run path:
$ path
Output:

/usr/local/sbin
/usr/local/bin
/usr/sbin
/usr/bin
/sbin
/bin
/usr/bin/X11
/usr/games

Source: http://www.cyberciti.biz/faq/howto-print-path-variable/