diffdir

#!/bin/bash
#
# diffdir
#

cmdline=diffdir

usagestr=$(
cat <<EOF

diffdir [options] d1 d2

d1	- first directory
d2	- second directory

Compares the text files in two directories and prints the names of
the files that differ to stdout.

Options
-------
-n	depth of search, where "-n 1" is topmost directory.
	space between switch and number is mandatory.
	Default depth is recursion through all subdirectories.

-h	this help text

\0
EOF
)

usage() {
	echo -e "$usagestr"
	exit 0
}

# rm_topdir 	- removes the top directory name, leaving only the sub
# 		  directories
# $1 - pathname
# $2 - return pathname with top directory stripped off
#
rm_topdir() {
	local path="$1"
	local len;

	[[ "${path:0:1}" == "/" ]] && path="${path:1}"
	[[ "${path:0:2}" == "./" ]] && path=${path:2}
	path="$(echo "$path" | cut -d'/' -f2-)"
	len=${#path}
	((len--))
	[[ -d "$path" ]] && [[ "${path:$len:1}" != "/" ]] && path="$path""/"
	eval $2=$path
}

# is_diff() - Compares two files. If they are different, prints the full
# 	      path names of the files side-by-side to stdout.
#
# $1 - first file
# $2 - second file
#
is_diff() {
	local f1=$1
	local f2=$2

	diff $f1 $f2 1> /dev/null
	[[ $? != 0 ]] && echo -e ""$f1"\t"$f2""
}

[ $# -gt 0 ] || usage

declare dir1
declare dir2
declare outfile
declare maxdepth
declare maxdepthstr=""

while getopts "n:h" OPTION; do
    case "$OPTION" in

        n ) maxdepth=$OPTARG
	    maxdepthstr="-maxdepth $maxdepth"
	    shift
	    shift
	    ;;
        h ) usage
	    ;;
        * ) echo "unrecognized option"
            echo "$usage"
            exit 1
	    ;;
    esac
done

dir1="$1"
dir2="$2"

export -f rm_topdir
export -f is_diff
export dir1
export dir2

find $dir1 $maxdepthstr -type f \
	-exec grep -Iq . {} \; \
	-exec sh -c \
	' \
		declare fspec; \
		rm_topdir $1 fspec; \
		ls $dir2/$fspec > /dev/null 2>&1; \
		[[ $? == 0 ]] && is_diff $dir1/$fspec $dir2/$fspec; \
	' \
	sh {} \;