git-recurse

#!/bin/sh

SEPARATOR=@@

# TODO this logic should probably rather be in rev-parse itself
# what it does:
#   whenever an expression foo@@bar is used as an argument
#   it checks whether foo is a valid reference, and if not, bar is used instead
processarg()
{
	prefix=
	suffix=
	case "$1" in
		# have to detect some rev-parse syntax
		*..*)
			first=${1%%..*}
			rest=${1#*..}
			first=`processarg "$first"`
			rest=`processarg "$rest"`
			echo "$first..$rest"
			;;
		*@\{*)
			first=${1%%@\{*}
			rest=${1#*@\{}
			first=`processarg "$first"`
			echo "$first@{$rest"
			;;
		*^*)
			first=${1%%^*}
			rest=${1#*^}
			first=`processarg "$first"`
			echo "$first^$rest"
			;;
		*~*)
			first=${1%%~*}
			rest=${1#*~}
			first=`processarg "$first"`
			echo "$first~$rest"
			;;
		*:*)
			first=${1%%:*}
			rest=${1#*:}
			first=`processarg "$first"`
			echo "$first:$rest"
			;;
		^*)
			first=${1#^}
			first=`processarg "$first"`
			echo "^$first"
			;;
		# handle foo@@bar so that if foo exists, foo stays, otherwise bar
		*$SEPARATOR*)
			first=${1%%$SEPARATOR*}
			rest=${1#*$SEPARATOR}
			if git rev-parse "$first" >/dev/null 2>&1; then
				echo "$first"
			else
				processarg "$rest"
			fi
			;;
		# other args stay as is
		*)
			echo "$1"
			;;
	esac
}
processargs()
{
	first=true
	for X in "$@"; do
		if $first; then
			first=false
			# clear arg list
			set --
		fi
		set -- "$@" "`processarg "$X"`"
	done
	echo >&2 "In `pwd`: $*"
	"$@"
}

# save stdin
exec 3<&0

# recurse through all sub-repos
status=0
# TODO is there a better way to identify all sub-repos?
find . -type d -name \*.git -prune | while IFS= read -r GITDIR; do
	# TODO I would LIKE to do this, but then some commands (like pull) fail
	#export GIT_DIR="$GITDIR"
	#export GIT_WORK_TREE="${GITDIR%/.git}"
	# so I will have to chdir instead

	( cd "$GITDIR/.." && processargs git "$@" <&3 3<&- ) # use restored stdin
	if [ "$?" -gt "$status" ]; then
		status=$?
	fi
done
exit "$status"