A shell script which can be added to Cron to update all git repos automatically

git-update.sh

#!/bin/bash
# Just change the FILES path below to the parent directory of where all your git repos reside
FILES=/dir/to/code/*
for f in $FILES
do
	if [ -d $f ] && [ -d $f/.git ]
		then
			echo "Processing Git repository, $f"
			cd $f
			git --git-dir="$f/.git" pull -q
	fi;
done