a template for a bash script à la make

bake.sh

#!/usr/bin/env bash
set -e
declare -a action;
RD='\e[31m'
GB='\e[33m'
BL='\e[34m'
RZ='\e[0m'

DEBUG=${DEBUG:-1}
ONE_VAR=${ONE_VAR:-template.dot}

echo -e "${GB}REPRODUCIBLE BUILD WITH"
echo -e      "-----------------------$RZ"
echo
for var in DEBUG ONE_VAR;
do
     printf "%s='%s' " "$var" "$( eval eval echo \\$\$var)"
done
echo -n $0 $@
echo
echo

d() {
    [ -z "$DEBUG" ] || echo -e "DEBUG:$(date +"%H:%M:%S"):$BL $* $RZ"
}

[ -d out ] || mkdir out


push() {
    local stack
    declare -a stack
    stack=( "$@" )
    for ((i=${#@}; i--; i)); do
        action=( "${stack[$i]}" "${action[@]}" );
    done
}


pop() {
    declare -n v=$1
    v=${action[0]}
    action=("${action[@]:1}")
}

set +x
dispatch_action() {
    while [[ ${#action} -gt 0 ]]; do
        pop act

        d "DISPATCHING $act"
        case $act  in
            all)
                [ -f out/this ] || push "before" ; dispatch_action
                touch out/that
                d all bells and whistles
                push "clean" ; dispatch_action
            ;;
            before)
                [ -f out/init ] || push init; dispatch_action
                d after init before all and clean
                touch out/this
            ;;
            init)
                d init : begin all
                touch out/init
            ;;
            clean)
                d clean everything
                set +e
                d out/*
                rm out/*
                set -e
            ;;
            *)
            echo unrecognized "$act";
                d "${action[@]}"
            break
            ;;
        esac
    done
}
if [ ! -z $1 ]; then
    action=( "$@" );
else
    push "all"
fi
dispatch_action
d fin