how do i implement exit status in a script?

dman777 · Veteran Joined: 10 Jan 2007 Posts: 1004

I've been told that it is better to have my bash script give the exit status when done. To me this seems redudant since the kernel will do this anyways. But, if I did implement exit status when my script is done, how would I do this? Don't I need to make a test condition for exit 0? What would I test for it to be true to exit 0?

durian · Guru Joined: 16 Jul 2003 Posts: 312 Location: Margretetorp

You can return a value (like "return 2") based on what your script has done. "return 0" if nothing went wrong, and "return 1" is some condition has occurred. If you don't return a value explicitly, your script will return the return value of the last function called, like you said.

-peter

dman777 · Veteran Joined: 10 Jan 2007 Posts: 1004

durian · Guru Joined: 16 Jul 2003 Posts: 312 Location: Margretetorp

In that case it would depend on the exit codes of the functions you call. After each function, you must check the result (which will be in the $? variable after a function call), and return that if it is not zero. Or keep count until the end, and then return something based on the intermediate results.

(edit mistakes). I found an example:

dman777 · Veteran Joined: 10 Jan 2007 Posts: 1004

see, this is one of the areas i am having a problem with. the $? will only return the exit status of the last command, not the last function. correct?

Nerevar · l33t Joined: 31 May 2008 Posts: 720

widremann · Veteran Joined: 14 Mar 2005 Posts: 1314

I am very confused as to what you are trying to accomplish here.

If you want to exit with a status, just do "exit 0" (or "exit 1" or whatever). As someone else pointed out, $? has the exit status of the last command or function. You can store this value in a variable for later use, if you really need to know the exit status of every function. Usually, if a function or command fails and that failure prevents the script from continuing to execute properly, you should go ahead and exit, so you don't really need to hold on to the value. You can just do exit $?, or save it in a variable, echo some error messages and then exit $SAVED.

dman777 · Veteran Joined: 10 Jan 2007 Posts: 1004

Mike Hunt · Watchman Joined: 19 Jul 2009 Posts: 5287

The last line is generally "exit" or "exit 0" or "exit $WHATEVER"

Take a look at Advanced Bash-Scripting Guide

i92guboj · Posted: Thu Sep 10, 2009 4:14 am Post subject:

A program can have many exit points. If it was just as simple as putting "exit 0" as the last line it would be pointless.

For example, imagine a simple script that calls feh to set the wallpaper, $1 will be the patch to the chosen wallpaper, right? Just quick code.