#!/bin/sh
# Execute a command and tag the output of the stdout and stderr streams.
self=tlcs

# Set the default prefixes and suffixes for stdout/err
out_pref='stdout: '
err_pref='stderr: '
out_suff=
err_suff=

# Parse options out, give help if necessary
while getopts 'co:e:' opt ; do
    case $opt in
        c)
            color=1
            ;;
        o)
            out_pref=$OPTARG
            ;;
        e)
            err_pref=$OPTARG
            ;;
        \?)
            printf >&2 'Unknown option %s\n' "$opt"
            exit 2
            ;;
    esac
done
shift "$((OPTIND-1))"

# We need at least one more argument
if [ "$#" -eq 0 ] ; then
    printf >&2 '%s: Need a command to run\n' "$self"
    exit 2
fi

# If color was requested for the output, try and get a count of available
# colors
[ -n "$color" ] && color_count=$( {
    tput colors || tput Co
} 2>/dev/null )

# If the color count is greater than 7, we'll color the output
if [ "$((color_count >= 8))" -eq 1 ] ; then

    # Color code for resetting
    color_reset=$( {
        tput me || tput sgr0
    } 2>/dev/null )

    # If stdout is a terminal, color it
    if [ -t 1 ] ; then
        color_stdout=$( {
            tput AF 2 || tput setaf 2
        } 2>/dev/null )
        out_pref=${color_stdout}${out_pref}
        out_suff=${out_suff}${color_reset}
    fi

    # If stderr is a terminal, color it
    if [ -t 2 ] ; then
        color_stderr=$( {
            tput AF 1 || tput setaf 1
        } 2>/dev/null )
        err_pref=${color_stderr}${err_pref}
        out_suff=${err_suff}${color_reset}
    fi
fi

# Create a temporary directory with name in $td, and handle POSIX-ish traps to
# remove it when the script exits.
td=
cleanup() {
    [ -n "$td" ] && rm -fr -- "$td"
    if [ "$1" != EXIT ] ; then
        trap - "$1"
        kill "-$1" "$$"
    fi
}
for sig in EXIT HUP INT TERM ; do
    # shellcheck disable=SC2064
    trap "cleanup $sig" "$sig"
done
td=$(mktd "$self") || exit

# Execute the command, passing stdout and stderr to tl(1) calls as appropriate
# via named pipes
out=$td/out err=$td/err
mkfifo -- "$out" "$err" || exit
tl -p "$out_pref" -s "$out_suff" < "$out" &
tl -p "$err_pref" -s "$err_suff" < "$err" &
"$@" >"$out" 2>"$err"
ex=$? ; wait ; exit "$ex"