git-rdiff

#!/bin/bash -e
## Show diff branch..origin/branch 
## for this repository and all submodules

## read input, display help if necessary
if [[ "$@" == *--help* ]]; then
    cat<<EOF
 Recursive diff

 This command compares local with remote branches recursively for
 each submodule and lists differing files.

 Usage:
    git rdiff
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
}

## continue silently, if there are unstaged changes
## we assume that such directories have already been merged.
## TODO: also show difference if fast forward is possible.
## TODO: if differences in submodules, show nicer output
if git check-clean --unstaged --unmerged --exit-code --ignore-submodules=dirty; then
    ## check if its a remote tracking branch and get it
    tmp=`git branch --no-color -vv 2> /dev/null`
    while read line; do
	if [[ "${line:0:1}" != "*" ]]; then
	    continue
	fi
	##echo "$line"
	branch=`expr "$line" : '\** *\([^ ]*\)'`
	remote=`expr "$line" : '.*\[\(.*\)\]'` || nontracking=0
	remote=`expr "$remote" : '\([^:]*\)'`
    done <<< "$tmp"

    if [[ "$nontracking" ]]; then
	cat >&2 <<EOF 
Error in $PWD:
 Not on a remote tracking branch.
EOF
    else 
	output=`git diff $branch..$remote --ignore-submodules --stat --no-ext-diff`

	if [[ "$output" != "" ]]; then
	    cat<<EOF 
Diff in $PWD:
 $output
EOF
	fi
    fi
fi

## check for differences in submodules
if [ -f .gitmodules ]; then
    #git submodule --quiet foreach git rdiff
    git submodule --quiet foreach 'echo "$toplevel/$path"' | 
    xargs -r -n1 -P5 bash -c 'cd "$1"; git rdiff' xargs
fi