apenwarr-redo/minimal/do

#!/bin/sh
#
# A minimal alternative to djb redo that doesn't support incremental builds.
# For the full version, visit http://github.com/apenwarr/redo
#
export REDO="$(cd "$(dirname "$0")" && echo "$PWD/$(basename "$0")")"

if [ -z "$DO_BUILT" ]; then
	export DO_BUILT="$PWD/.do_built"
	if [ -e "$DO_BUILT" ]; then
		echo "Removing previously built files..." >&2
		sort -u "$DO_BUILT" | tee "$DO_BUILT.new" |
		while read f; do rm -f "$f"; done
		mv "$DO_BUILT.new" "$DO_BUILT"
	fi
	DO_PATH="$DO_BUILT.dir"
	export PATH="$DO_PATH:$PATH"
	rm -rf "$DO_PATH"
	mkdir "$DO_PATH"
	for d in redo redo-ifchange; do
		ln -s "$REDO" "$DO_PATH/$d";
	done
	for d in redo-ifcreate redo-stamp redo-always; do 
		ln -s /bin/true "$DO_PATH/$d";
	done
fi


_dirsplit()
{
	OLDIFS="$IFS"
	IFS=/
	set -- $1
	IFS="$OLDIFS"
	dir=""
	while [ $# -gt 1 ]; do
		dir="$dir$1/"
		shift
	done
	base="$1"
}


_do()
{
	DIR="$1"
	TARGET="$2"
	if [ ! -e "$TARGET" ]; then
		printf '\033[32mdo  %s\033[1m%s\033[m\n' \
			"$DO_DEPTH" "$DIR$TARGET" >&2
		echo "$PWD/$TARGET" >>"$DO_BUILT"
		dof=".$TARGET"
		DOFILE="$TARGET.do"
		BASE="$TARGET"
		EXT=""
		while [ ! -e "$DOFILE" ]; do
			dof2=$(echo "$dof" | sed 's/\.[^\.]*//')
			[ "$dof" = "$dof2" ] && break
			dof="$dof2"
			DOFILE="default$dof.do"
			BASE="$(basename "$TARGET" "$dof")"
			EXT="$dof"
		done
		set "$BASE" "$EXT" "$TARGET.tmp"
		RV=
		( 
			export DO_DEPTH="$DO_DEPTH  "
			export REDO_TARGET="$PWD/$TARGET"
			set -e
			. "$PWD/$DOFILE" >"$TARGET.tmp"
		) || RV="$?"
		[ -z "$RV" ] && mv "$TARGET.tmp" "$TARGET" 2>/dev/null
		: >>"$TARGET"
		if [ -n "$RV" ]; then
			printf "do: %s%s\n" "$DO_DEPTH" \
				"$DIR$TARGET: got exit code $RV" >&2
			return $RV
		fi
	else
		echo "do  $DO_DEPTH$TARGET exists." >&2
	fi
}


redo()
{
	for i in "$@"; do
		_dirsplit "$i"
		( cd "$dir" && _do "$dir" "$base" ) || return 1
	done
}


set -e
if [ -n "$*" ]; then
	redo "$@"
else
	redo all
fi