git pre-commit

#!/bin/sh
# make sure the script, named pre-commit, is in .git/hooks/ and is executable!
EXIT_STATUS=1;
MAIN_LAYOUT_FILE="path/to/main/layout.html._or_what_have_you";
DATE_VERSION=`date '+%Y.%m%d.%H%M'`

if [ -e $MAIN_LAYOUT_FILE ]
then
  `sed -i "s/<span id='VERSION_ID'>.*<\/span>/<span id='VERSION_ID'>$DATE_VERSION<\/span>/" $MAIN_LAYOUT_FILE`;
  EXIT_STATUS=0;
else
  echo "Missing layout file: $MAIN_LAYOUT_FILE\n";
fi

# if EXIT_STATUS != 0 it will stop the whole commit
exit $EXIT_STATUS;