git-commit-vandalism/git-sh-setup.sh

#!/bin/sh
#
# This is included in commands that either have to be run from the toplevel
# of the repository, or with GIT_DIR environment variable properly.
# If the GIT_DIR does not look like the right correct git-repository,
# it dies.

# Having this variable in your environment would break scripts because
# you would cause "cd" to be be taken to unexpected places.  If you
# like CDPATH, define it for your interactive shell sessions without
# exporting it.
unset CDPATH

die() {
	echo >&2 "$@"
	exit 1
}

usage() {
	die "Usage: $0 $USAGE"
}

if [ -z "$LONG_USAGE" ]
then
	LONG_USAGE="Usage: $0 $USAGE"
else
	LONG_USAGE="Usage: $0 $USAGE

$LONG_USAGE"
fi

case "$1" in
	-h|--h|--he|--hel|--help)
	echo "$LONG_USAGE"
	exit
esac

if [ -z "$SUBDIRECTORY_OK" ]
then
	: ${GIT_DIR=.git}
	: ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}

	# Make sure we are in a valid repository of a vintage we understand.
	GIT_DIR="$GIT_DIR" git repo-config --get core.nosuch >/dev/null
	if test $? = 128
	then
	    exit
	fi
else
	GIT_DIR=$(git-rev-parse --git-dir) || exit
fi