cpplint pre-commit hook

cpplint_pre_commit_hook.sh

#!/bin/sh
#
# Modified from http://qiita.com/janus_wel/items/cfc6914d6b7b8bf185b6
#
# An example hook script to verify what is about to be committed.
# Called by "git commit" with no arguments.  The hook should
# exit with non-zero status after issuing an appropriate message if
# it wants to stop the commit.
#
# To enable this hook, rename this file to "pre-commit".

# Added a prompt to allow commiting anyways even if there are style isseus. 
# Put filters in an array. I thought it was easier to add or remove them when each one is on its own line.

# If we have a STDIN, use it, otherwise get one
if tty >/dev/null 2>&1; then
    TTY=$(tty)
else
    TTY=/dev/tty
fi

# http://djm.me/ask
ask() {
    while true; do

        if [ "${2:-}" = "Y" ]; then
            prompt="Y/n"
            default=Y
        elif [ "${2:-}" = "N" ]; then
            prompt="y/N"
            default=N
        else
            prompt="y/n"
            default=
        fi

        # Ask the question (not using "read -p" as it uses stderr not stdout)
        echo -n "$1 [$prompt] "

        # Read the answer
        read REPLY < "$TTY"

        # Default?
        if [ -z "$REPLY" ]; then
            REPLY=$default
        fi

        # Check if the reply is valid
        case "$REPLY" in
            Y*|y*) return 0 ;;
            N*|n*) return 1 ;;
        esac

    done
}

if git rev-parse --verify HEAD >/dev/null 2>&1
then
  against=HEAD
else
  # Hash for empty tree
  against=$(git hash-object -t tree /dev/null)
fi

# Redirect output to stderr.
exec 1>&2

cpplint=cpplint
sum=0

declare -a filters=(
"-build/include"
"-build/include_order"
"-build/namespaces"
"-legal/copyright"
"-runtime/references"
"-whitespace/indent"
"-build/header_guard"
"-whitespace/line_length"
"-readability/namespace"
)

filters_joined=$(IFS=",$IFS"; printf '%s\n' "${filters[*]}")
        
# for cpp
for file in $(git diff-index --name-status $against -- | grep -E '\.[ch](pp)?$' | awk '{print $2}'); do
    $cpplint --filter=$filters_joined $file
    sum=$(expr ${sum} + $?)
done

if [ ${sum} -ne 0 ]; then
  if ask "Files do not match style guidle. Commit anyway?"; then
    exit 0
  else
    exit 1
  fi
fi