Extracts changed files from a specified commit into an output directory

git-extract.sh

#!/bin/sh
set -e

usage() {
  echo "usage: git-extract.sh commit output-directory"
}

extract() {
  FILES=`git diff-tree --oneline --no-commit-id --name-only -r $1`
  for file in $FILES
  do
    dirname=`dirname "$file"`
    `mkdir -p "$2/$dirname"`
    `cp "$file" "$2/$file"`
  done
}

if [ $# -ne 2 ]
then
  usage
  exit 1
else 
  extract $1 $2
fi