#!/bin/sh

######################################################################
#
# dirmd5
#
# SYNOPSIS
#
#     dirmd5 [PATH]
#
# DESCRIPTION
#
#     This returns the md5sum of an entire directory. The only argument is the
#     path to process. If no path is given then the current directory is used.
#     It attempts to detect filename changes and to compensate for sort
#     differences in different filesystems. It does not yet take into account
#     file permissions, nor show differences in two different directory
#     structures.
#
# EXAMPLES
#
#     $ dirmd5 /home/noah/project 70b8fd2ac11844e9507e30a980ecdc00
#
# EXIT STATUS
#
#     This exits with status 0 on success or non-zero on error.
#
# AUTHOR
#
#     Noah Spurrier <noah@noah.org>
#
# LICENSE
#
#     This license is OSI and FSF approved as GPL-compatible. This license
#     identical to the ISC License and is registered with and approved by the
#     Open Source Initiative. For more information vist:
#     http://opensource.org/licenses/isc-license.txt
#
#     Copyright (c) 2013, Noah Spurrier <noah@noah.org>
#
#     Permission to use, copy, modify, and/or distribute this software for any
#     purpose with or without fee is hereby granted, provided that the above
#     copyright notice and this permission notice appear in all copies.
#
#     THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
#     WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
#     MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
#     ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
#     WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
#     ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
#     OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
# VERSION
#
#     Version 1
#
######################################################################

if [ "$1" ]; then
	ROOT_PATH="$1"
else
	ROOT_PATH="$(pwd)"
fi
ROOT_PATH="$(cd ${ROOT_PATH} && pwd)"
# Follow the first sym-link, if any.
if readlink ${ROOT_PATH}; then
	ROOT_PATH=$(readlink ${ROOT_PATH})
fi


# find -name .git -prune -o -type f -print | while read fn; do md5sum -b "${fn}" | sed 's/^\([[:xdigit:]]\+\).*/\1/'; done
#     does the same this as...
# find -name .git -prune -o -type f -exec md5sum -b "{}" \; | sed 's/^\([[:xdigit:]]\+\).*/\1/'
(
	cd "${ROOT_PATH}"
	find -name .git -prune -o -type f -exec md5sum -b "{}" \; | sed 's/^\([[:xdigit:]]\+\).*/\1/'
	find -name .git -prune -o -print | LC_ALL=C sort | md5sum -b | sed 's/^\([[:xdigit:]]\+\).*/\1/'
) | LC_ALL=C sort | md5sum -b | sed 's/^\([[:xdigit:]]\+\).*/\1/'