#!/bin/sh
#
# This pre-commit hook checks if clang-format-7
# is installed, and if so, uses the installed version to format
# the staged changes.

base=clang-format-7
format=""

# Redirect output to stderr.
exec 1>&2

 # check if clang-format is installed
type "$base" >/dev/null 2>&1 && format="$base"

# no versions of clang-format are installed
if [ -z "$format" ]
then
    echo "$base is not installed. Pre-commit hook will not be executed."
    exit -1
fi

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

# do the formatting
for file in `git diff-index --cached --name-only $against`
do
    "$format" -style=file -i "$file"
done