parse signal values in status codes

[anarcat]

After realizing I was in the process of rewriting something similar to powerline in bash, I figured I would give this project a try again.

One of the things my fancy bash prompt does (thanks to help from some friends ;), is to display properly status code issued from signals received from the shell. For example:

anarcat@curie:~(master)$ true
anarcat@curie:~(master)$ ( exit 1 )
[1]anarcat@curie:~(master)$ ( sleep 10 )
Complété
[SIGTERM]anarcat@curie:~(master)$ 

First prompt exited cleanly: no error. Status code 1 get displayed as is, but the sleep call (which i interrupted in another window), gets shown with the proper signal (instead of, say, "status code 143").

This is how the above looks in powerline:

 anarcat   master  ~  true
 anarcat   master  ~  (exit 1)
 anarcat   master  ~  1  (sleep 10)
Complété
 anarcat   master  ~  143  

forgive the private unicode... But basically, what would be nice would be to parse status codes above 128 for the signal value. here's the bash we're using for that:

__exit_codes_to_SIGs () {
    local -n sig_status=$1 ; shift
    local exit_codes=( "$@" )
    local i=0
    for exit_code in "${exit_codes[@]}" ; do
	if [ "$exit_code" -gt 128 ] ; then
	    local signal=$((exit_code-128))
	    signal="SIG$(kill -l "$signal" 2> /dev/null)" ||
		signal=""
	    if [ -n "$signal" ] ; then
		sig_status[$i]="${magenta}${signal}${reset}"
	    else
		sig_status[$i]="${red}${exit_code}${reset}"
	    fi
	elif [ "$exit_code" -ne 0 ] ; then
	    sig_status[$i]="${red}${exit_code}${reset}"
	fi
	i=$((i+1))
    done
}

It's a nasty piece of work with arrays and everything, but it works fairly well. It does, incidentally, make control-c look much better than in powerline:

anarcat@curie:~(master)$ ^C
[SIGINT]anarcat@curie:~(master)$ 

In powerline:

 anarcat   master  ~  ^C
 anarcat   master  ~  130  

Thanks!