git-cpush

#!/bin/bash -e
## Do a conditional push: only push, if remotes are behind
## otherwise accept the same arguments as push

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

 This command is similar to git-push, but only executes the push
 if necessary.
 Before pushing, the submodules are pushed.

 Usage:
    git cpush ...

    ...: same arguments as git-push
EOF
    exit 0;
fi

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


## push submodules first
if [ -f $(git rev-parse --show-toplevel)/.gitmodules ]; then
    CMD='cd "$1"; git cpush '"$@"
    #git submodule --quiet foreach git cpush "$@" || exit 1
    git submodule --quiet foreach 'echo "$toplevel/$path"' | 
    xargs -r -n1 -P5 bash -c "$CMD" xargs || exit 1
fi

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" : '\** *\([^ ]*\)'`
    ##echo "$branch"
    remote=`expr "$line" : '.*\[\(.*\)\]'` || continue
    ##echo "$remote"
    ## if we're ahead: branch will show it after ":" 
    status=`expr "$remote" : '.*: ahead \(.*\)'` || continue
    ##echo "$status"
    unpushed=" Branch \"$branch\" is ahead by $status commit(s)."
done <<< "$tmp"

## push also if --tags argument is given
if [[ "$@" == *--tags* ]]; then
    unpushed="Push tags"
fi

if [ "$unpushed" ]; then
    echo "Pushing $PWD."
    git push "$@"
fi