git-rm-orphaned-submodule-dirs

#!/bin/bash -e
## Remove orphaned submodule directories

## read input, display help if necessary
if [[ "$@" == *--help* ]]; then
    cat<<EOF
 Remove orphaned submodule directories

 This command removed orphaned submodule directories, i.e., if a
 submodule was removed (or han its url changed) but the directory was
 not removed because it was not empty. Before removing a directory,
 the script checks for any changes that might be lost. Afterwards, a
 submodule sync is executed.

 Usage:
    git rm-orphaned-submodule-dirs
EOF
    exit 0;
fi

## from the git mailinglist:
function git
{
    LC_MESSAGES=C command git "$@"
} 
export git

## ensure we are in the toplevel directory
cdup=$(git rev-parse --show-toplevel) &&
cd "$cdup" || {
    echo >&2 "Cannot chdir to $cdup, the toplevel of the working tree"
    exit 1
}

## ensure we will not remove the toplevel git directory
rootgitdir=$(cd `git rev-parse --git-dir`; pwd)

## find submodule urls not in .gitmodules:
git config --get-regexp submodule.*url |
while read key url; do
    #echo "$key"
    dir=`expr "$key" : 'submodule\.\(.*\)\.url'`
    #echo "$dir"
    if [[ -d "$dir" && $(git config -f .gitmodules --get "$key") != "$url" ]]; then
	tdir=$PWD
	## Check if the directory is clean
	cd "$dir"
	git check-clean || exit 1
	git check-unpushed || exit 1
	git check-non-tracking || exit 1
        ## find the real git-dir (might be git-file, for v.1.7.8 compatibility)
	## git dir should be relative to current dir... but is it?
	gitdir=$(cd `git rev-parse --git-dir`; pwd)
	cd "$tdir"
	rm -rf "$dir"
        ## remove git dir as well (might git-file, for v.1.7.8 compatibility)
        ## but only if it's not equal to root dir
	if [[ "$gitdir" != "$rootgitdir" ]]; then
	    rm -rf "$gitdir"
	fi
    fi
done

git submodule sync > /dev/null