const glob = require("glob"), fs = require("fs"); let foundFiles = []; glob.sync("pages/**/*.{html,md}").forEach(function (file) { let fileContent = fs.readFileSync(file); fileContent.toString().replace(/\{% include(_cached)? ([a-z0-9\/_-]+\.html)/g, function(f, c, filename){ filename = 'pages/_includes/' + filename; if(!foundFiles.includes(filename)) { foundFiles.push(filename); } }); }); let includeFiles = glob.sync("pages/_includes/**/*.html"); includeFiles.forEach(function(file){ if(! foundFiles.includes(file)) { console.log('file', file); } }); // console.log('foundFiles', foundFiles); // console.log('includeFiles', includeFiles);