Grunt task to search and replace strings in file

Gruntfile.js

module.exports = function(grunt) {

    // Load grunt tasks automatically
    require('load-grunt-tasks')(grunt);

    // Time how long tasks take. Can help when optimizing build times
    require('time-grunt')(grunt);

    // Project configuration.
    grunt.initConfig({
        // options for find and replace task
        findreplace: {
            cssfiles: {
                files: [
                    'css/styles.css',
                    'css/bootstrap.css'
                ],
                strings: [
                    ['images/', 'img/'],
                    ['../', '/']
                ]
            }
        }
    });

    /*
     * Find and replace function - primarilly written to update paths in the CSS files
     * With the config above, this function will find-replace in css/styles.css and css/bootstrap.css
     * It will replace and instance of images/ with img/ and ../ with /
     */
    grunt.registerTask('findreplace', 'find and replace strings in files', function() {
        var complete = this.async();
        var config = grunt.config('findreplace');

        for (var c in config) {
            var files   = config[c].files, strings = config[c].strings;
            for (var f=0, g=files.length; f < g; f++) {
                if (grunt.file.isFile(files[f])) {
                    var content = grunt.file.read(files[f]);
                    for (var s=0, t=strings.length; s < t; s++) {
                        if (strings[s].length===2) {
                            var escapedstrings = strings[s][0].replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
                            var findregex = new RegExp(escapedstrings,'g');
                            var finds = content.match(findregex) || [];
                            grunt.log.writeln(files[f]+' : replacing '+strings[s][0]+' with '+strings[s][1]+' : '+finds.length+' match(es)');
                            
                            content = content.replace(findregex,strings[s][1]);
                        }
                    }
                    grunt.file.write(files[f], content);
                }
            }
        }
        complete();
    });

};