SHELL general function for action state

Question

How to make a code bellow as a general function to be used entire script in bash:

if [[ $? = 0 ]]; then 
    echo "success " >> $log
else echo "failed" >> $log
fi

Related and very useful: [What is the best way to write a wrapper function that runs commands and logs their exit code](http://stackoverflow.com/a/372120/1983854) — fedorqui, Oct 25 '13 at 11:14

hek2mgl · Answer 1 · 2013-10-25T12:17:57.610

2

You might write a wrapper for command execution:

function exec_cmd {
    $@
    if [[ $? = 0 ]]; then 
        echo "success " >> $log
    else 
        echo "failed" >> $log
    fi
}

And then execute commands in your script using the function:

exec_cmd command1 arg1 arg2 ...
exec_cmd command2 arg1 arg2 ...
...

edited Oct 25 '13 at 12:17

answered Oct 25 '13 at 11:08

hek2mgl

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as @fedorqui linked, `"$@"` would make life a lot easier here – jozxyqk Oct 25 '13 at 11:42

score 0 · Answer 2 · answered Oct 25 '13 at 11:10

If you don't want to wrap the original calls you could use an explicit call, like the following

function check_success {
    if [[ $? = 0 ]]; then 
        echo "success " >> $log
    else echo "failed" >> $log
    fi
}



ls && check_success

ls non-existant
check_success

score 0 · Answer 3 · answered Oct 25 '13 at 11:14

0

There's no really clean way to do that. This is clean and might be good enough?

PS4='($?)[$LINENO]'
exec 2>>"$log"

That will show every command run in the log, and each entry will start with the exit code of the previous command...

answered Oct 25 '13 at 11:14

Mark Reed

91,912
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score 0 · Answer 4 · edited May 23 '17 at 12:28

You could put this in .bashrc and call it whenever

function log_status { [ $? == 0 ] && echo success>>/tmp/status || echo fail>>/tmp/status }

If you want it after every command you could make the prompt write to the log (note the original PS1 value is appended).

export PS1="\$([ \$? == 0 ] && echo success>>/tmp/status || echo fail>>/tmp/status)$PS1"

(I'm not experienced with this, perhaps PROMPT_COMMAND is a more appropriate place to put it)

Or even get more fancy and see the result with colours.

I guess you could also play with getting the last executed command:

SHELL general function for action state

4 Answers4