Check if the target path has the expected permissions

check_file_perms.sh

#! /bin/bash

# Author: Lorenzo Gaggini - lorenzo.gaggini@dada.eu
# Check if a the target path has the expected permissions
#
# Usage: ./check_file_perms.sh -t target_path -p expected_permissions


function usage()
{
    echo "Usage:"
    echo "./check_file_perms.sh -t target_path -p expected_permissions"
    echo "-t (required): path to check for permissions"
    echo "-p (required): expected octal permssisions for target_path"
}


while getopts ":ht:p:" opt; do
    case ${opt} in
        h ) usage && exit 0;;
        t ) target_path=$OPTARG;;
        p ) exp_perms=$OPTARG;;
        \?|*) usage && exit 1;;
    esac
done


if [ ! -d "${target_path}" ]; then
    echo "${target_path} doesnt exists"
    exit 1
fi

if [[ ! ${exp_perms} =~ ^[0-1][0-7]{3}$ ]]; then
    echo "${exp_perms} is not a valid octal permissions"
    exit 1
fi

current_perms=$(stat -c "%a" "${target_path}")

if [ "${exp_perms}" = "${current_perms}" ]; then
    echo "OK, ${target_path} has the expected permissions: ${exp_perms}"
    exit 0
else
    echo "KO, ${target_path} has unexpected permissions: ${current_perms}, should be ${exp_perms}"
    exit 2
fi