protect master branch on git

pre-push.sh

#!/bin/bash

protected_branch='master'

policy="\n\n[Policy] Never push code directly to the "$protected_branch" branch! (Prevented with pre-push hook.)\n\n"

current_branch=$(git symbolic-ref HEAD | sed -e 's,.*/\(.*\),\1,')

push_command=$(ps -ocommand= -p $PPID)

is_destructive='force|delete|\-f'

will_remove_protected_branch=':'$protected_branch

do_exit(){
  echo -e $policy
  exit 1
}

if [[ $push_command =~ $is_destructive ]] && [ $current_branch = $protected_branch ]; then
  do_exit
fi

if [[ $push_command =~ $is_destructive ]] && [[ $push_command =~ $protected_branch ]]; then
  do_exit
fi

if [[ $push_command =~ $will_remove_protected_branch ]]; then
  do_exit
fi

# Prevent ALL pushes to protected_branch
if [[ $push_command =~ $protected_branch ]] || [ $current_branch = $protected_branch ]; then
  do_exit
fi

unset do_exit

exit 0