#!/bin/bash

filter()
{
   case "$1" in
     -m)
         grep -B1 '^ M'
         ;;
     *)
         cat
         ;;
   esac
}

for dir in *
do    
    [ -f $dir/.git/index.lock ] && echo "$dir has .git/index.lock" 
    [ -d $dir/.git ] && (cd $dir; echo $dir; git status --short -uno )
done | filter $1
