how to process files on a branch in post-receive hook in git

• For 1), you have an example of reading the branch name (through stdin):
  “Not able to detect branch from Git post-receive hook”
• For 2), you need to set GIT_WORK_TREE appropriately:
  “Managing website using git + post-receive hook: error pushing changes”

See both techniques combined in “Git post-receive for multiple remote branches and work-trees”:

#!/bin/bash

while read oldrev newrev ref
do
  branch=`echo $ref | cut -d/ -f3`

  if [ "master" == "$branch" ]; then
    git --work-tree=/path/under/root/dir/live-site/ checkout -f $branch
    echo 'Changes pushed live.'
  fi

  if [ "dev" == "$branch" ]; then
    git --work-tree=/path/under/root/dir/dev-site/ checkout -f $branch
    echo 'Changes pushed to dev.'
  fi
done