launch a command in the background and notify the user when it's done

nm.zsh

#!/usr/bin/env zsh
main()
{
    START=$(date +%s)
    STARTT="$(date)"
    OUT="$(mktemp nm.XXXXXXXXXX)"
    echo "the launchpath was $(pwd) with pid $$" > $OUT
    echo "the received output is:" >> $OUT
    if [ "$1" = "-" ]
    then 
        cat - &>> $OUT
    else 
        $@ &>> $OUT 
    fi
    echo "------\nend of message" >> $OUT
    SUB="Launch '$@' is done!  --  $(date)"
    SEDEXP='1i "'$@'" was launched by launched by "'$(whoami)@$(hostname)'" on "'$STARTT'" ran for '$(($(date +%s)-$START))'s'
    sed -i "$SEDEXP" $OUT
    notify-send --urgency=critical "$SUB" "$(tail --bytes 1024 $OUT)"
    rm -f $OUT
}
if [ $# -eq 0 ]
then
    echo "nm: to what do I owe the extreme pleasure of this visit?"
else
    main "$@" &
    disown
fi
exit 0