Catch exit code before pipe in bash script?

prl77 · 05-14-2012, 09:31 PM

I have a bash script that runs a command and pipes its output to 'tee' which splits it into two log files for later parsing. I need to catch the exit code from the command right before piping. How?

Code:

/usr/bin/command1 parameter1 --option1 2>&1 | tee -a $LOG1 $LOG2
        if [ $? != 0 ]; then
                do some shit
        else
                do other shit
        fi

It appears that I'm catching the result of 'tee' and not of 'command1'.

Thanks,
prl77

PS. I'm going on vacation tomorrow, will respond back in a week.

catkin · 05-14-2012, 09:44 PM

The bash variable PIPESTATUS:

Quote:

An array variable (see Arrays) containing a list of exit status values from the processes in the most-recently-executed foreground pipeline (which may contain only a single command).

Code:

c@CW8:~$ false | true | echo foo
foo
c@CW8:~$ echo ${PIPESTATUS[0]} ${PIPESTATUS[1]} ${PIPESTATUS[2]}
1 0 0

towheedm · 05-14-2012, 09:47 PM

Remember, '$?' always returns the exit status of the last command, in your case the 'tee' command. What you can do, is save the output of command1 to a var first. You must also save the exit status to another var first if tee must be executed before the conditionals.

Hope it points you in the right direction.

towheedm · 05-14-2012, 09:48 PM

Aha, PIPESTATUS, something new for me learn about.

prl77 · 05-24-2012, 12:09 PM

Quote:

Originally Posted by catkin

The bash variable PIPESTATUS:

Code:

c@CW8:~$ false | true | echo foo
foo
c@CW8:~$ echo ${PIPESTATUS[0]} ${PIPESTATUS[1]} ${PIPESTATUS[2]}
1 0 0

This hit the spot. Thanks man!