Shellcheck pre-commit hook

pre-commit

#!/bin/sh
#
# This pre-commit hook run `shellcheck` against your code when you go to commit.
# See: http://www.shellcheck.net/
#
# To use this script copy it to .git/hooks/pre-commit and make it executable.

# Work out what to diff against, really HEAD will work for any established repository.
if git rev-parse --verify HEAD >/dev/null 2>&1
then
  against=HEAD
else
  # Initial commit: diff against an empty tree object
  against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi

# get updated files | only .sh files (+ .bashrc/.zshrc) | shellcheck
git diff-index --cached --name-only $against | grep -e \.bashrc -e \.zshrc -e \.bash_profile -e \\.sh$ | xargs shellcheck