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THE "PATH"


As you type a command in a console you do not have to know the full PATH to that command or program, just the name will do. Type ¨kmail¨ and it will bring up the Kmail program, type ¨cp fileX /mnt/win_c¨ and it will call on the ¨cp¨ executable to copy ¨fileX to the Windows C: partition. No need to type the full path to those executables.

This is because the Kmail and the cp executables are ¨in your PATH¨ ( the full paths are /usr/bin/kmail and /bin/cp )
Most of these executables for normal users are stored in /bin, /usr/bin and /usr/local/bin, thus these directories are ¨in your PATH¨

Sometimes however programs are stored in unusual places, or you make your own scripts and programs and store them in a special directory. Then we can add those directories to ¨your PATH¨, so that a simple short command can call them.

First let´s have a look what´s in your path:

CODE
$ echo $PATH


You will see something like:

/usr/X11R6/bin:/usr/local/bin:/bin:/usr/bin:/usr/games:/usr/lib/jre-1.4.1_01/bin

What this means is /usr/X11R6/bin and /usr/local/bin/ and /bin etc. are in your PATH

For root:

CODE
$ su
< password >
# echo $PATH


Will give this line:

/sbin:/usr/sbin:/bin:/usr/bin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin


You notice that the PATHs are different for root than for the normal user ! ( ¨sbin¨ is a good give-away that they are for root )


Now let´s assume you want to add the /home/bruno/progs/exec directory ( where you store your own executables ) to your PATH:

CODE
# export PATH=$PATH:/home/bruno/progs/exec


Now you can just type ¨back¨ at the prompt to call on your self-written backup-script or program that you have in /home/bruno/progs/exec.

To permanently add something to the PATH you will have to edit a file, could be in a few different ones ( depending on shell and distro): ~/.profile or ~/.bash_profile or /etc/profile or /etc/csh.login. ( More in-depth and accurate info can be found Here )

There is a line like:

PATH=$PATH:$HOME/bin


Just add a colon and the new directory, like this:

PATH=$PATH:$HOME/bin:/home/bruno/progs/exec


And save the file. To load the new settings either reboot or:

CODE
# source /etc/skel/.bash_profile


Now you know next time you see the error message that something is not ¨in your PATH¨ how to solve this little problem.



UPDATE: Another way to add permanently to the PATH is:

CODE
$ export PATH=$PATH:/home/bruno/progs/exec




Bruno


-- Jul 7 2003 ( Revised Jun 5 2006 ) --


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