commit size pre-receive hook

pre-receive

#!/bin/sh

GITCMD="/usr/local/bin/git"
NULLSHA="0000000000000000000000000000000000000000"
MAXSIZE="5242880" # 5MB limit on file size
EXIT=0

# Read stdin for ref information
while read oldref newref refname; do
  # Skip branch deletions
  if [ "${newref}" = "${NULLSHA}" ]; then
    continue;
  fi

  # Set oldref properly if this is branch creation.
  if [ "${oldref}" = "${NULLSHA}" ]; then
    oldref="HEAD"
  fi

  # Get list of files to look at using git diff
  for file in $($GITCMD diff --stat --name-only --diff-filter=ACMRT ${oldref}..${newref}); do
    # Get the size of this file
    size=$($GITCMD cat-file -s ${newref}:${file})
    # Check to see if for some reason we didn't get a size
    if [ ! -z ${size} ]; then
      # Compare filesize to MAXSIZE
      if [ "${size}" -gt "${MAXSIZE}" ]; then
        # Send output back to the user about oversized files.
        echo "ERROR: ${file} larger than ${MAXSIZE}."
        EXIT=1
      fi # End size comparison
    fi   # End check for empty size
  done   # End list of files
done     # End reading stdin

# If we have oversized files, write more information out to the user
if [ "${EXIT}" = "1" ]; then
  echo "ERROR: Your commit has been blocked due to certain files being oversized."
  echo "ERROR: Check output above for more information."

The script is missing a fi for grammar, and at the end it should exit with $EXIT.
It doesn't prevent huge files ending in the repository if the sender has removed them on his copy.