Helper script for passing selected files in Windows Explorer to WScript via StExBar. Processes with external programs such as jpegtran and pngout

optimg.js

/*
 * optimg.js
 * This file runs optimg optimization on all selected files
 *
 * To use with StExBar, add the command line:
 * WScript.exe "path/to/optimg.js" //E:javascript %sel*paths
 */
(function (WScript, Error, String) {
    "use strict";

    var argv, argc, errno = {};
    errno.EEXIST = 58;

    argv = WScript.Arguments;
    argc = argv.length;

    if (argc < 1) {
        WScript.Echo("Usage: [CScript | WScript] optimg.js path/to/file(s)");
        WScript.Quit(1);
    }

    // Functions
    var basename = function (path) {
        return path.replace(/\\/g, '/').replace(/.*\//, '');
    };

    var dirname = function (path) {
        return path.replace(/\\/g, '/').replace(/\/[^\/]*\/?$/, '');
    };

    var noext = function (path) {
        return path.substr(0, path.lastIndexOf('.')) || input;
    };

    var getext = function (path) {
        return path.split('.').pop();
    };

    // Ensure support for an "endswith" function to the String prototype
    if (typeof String.prototype.endswith !== 'function') {
        String.prototype.endswith = function (suffix) {
            return this.indexOf(suffix, this.length - suffix.length) !== -1;
        };
    }

    var optimg = function (obj) {
        obj = obj || {};

        if (typeof obj.imagePaths === "undefined") {
            throw new Error("optimg requires a path to a directory of images");
        }

        if (typeof obj.outDirectory === "undefined") { obj.outDirectory = "opt"; }
        if (typeof obj.delimiter === "undefined") { obj.delimiter = " "; }
        if (typeof obj.suffix === "undefined") { obj.suffix = ""; }

        if (typeof obj.jpgBinary === "undefined") { obj.jpgBinary = "jpegtran"; }
        if (typeof obj.pngBinary === "undefined") { obj.pngBinary = "pngout"; }

        if (typeof obj.jpegtranArgs === "undefined") {
            obj.jpegtranArgs = "-copy none -optimize -progressive";
        }
        if (typeof obj.pngoutArgs === "undefined") {
            obj.pngoutArgs = "";
        }

        var fso, shell, files, jpgCommand, pngCommand, i, f, d, b, optname,
            tmpfile, tmpstream, runstrings;
        runstrings = [];

        // remove the quotes
        fso = WScript.CreateObject("Scripting.FileSystemObject");
        shell = WScript.CreateObject("WScript.Shell");

        files = obj.imagePaths.replace(/\"(.*)\"/, "$1").split(obj.delimiter);

        if (obj.jpgBinary === "jpegtran") {
            jpgCommand = obj.jpgBinary + " " + obj.jpegtranArgs;
        }
        if (obj.pngBinary === "pngout") {
            pngCommand = obj.pngBinary + " " + obj.pngoutArgs;
        }

        for (i = 0; i < files.length; i += 1) {

            f = files[i];

            if (f.toLowerCase().endswith(".jpg")) {
                d = dirname(f) + '/' + obj.outDirectory + '/';
                try {
                    fso.CreateFolder(d);
                } catch (e) {
                    /*jslint bitwise: false */
                    if (e.number & 0xFFFF !== errno.EEXIST) { throw e; }
                    /*jslint bitwise: true */
                }
                b = basename(f);
                optname = d + noext(b) + obj.suffix + "." + getext(b);
                runstrings.push(jpgCommand + " \"" + f + "\" \"" + optname + "\"");

            } else if (f.toLowerCase().endswith(".png")) {
                d = dirname(f) + '/' + obj.outDirectory + '/';
                try {
                    fso.CreateFolder(d);
                } catch (e) {
                    /*jslint bitwise: false */
                    if (e.number & 0xFFFF !== errno.EEXIST) { throw e; }
                    /*jslint bitwise: true */
                }
                b = basename(f);
                optname = d + noext(b) + obj.suffix + "." + getext(b);

                runstrings.push(pngCommand + " \"" + f + "\" \"" + optname + "\"");
            }
        }

        // WARN: Use a temporary file or you will hit the max char limit for cmd /c
        tmpfile = shell.ExpandEnvironmentStrings("%TEMP%") + "/optimg.bat";
        tmpstream = fso.CreateTextFile(tmpfile, true);
        tmpstream.Write(runstrings.join("\n"));
        tmpstream.Close();

        //
        // Use cmd /c so that you can interpret multiple commands or bat files
        // without having to spawn _n_ number of shells for _n_ commands
        //
        // NOTE: (7) Displays the window as a minimized window.
        //           The active window remains active.
        shell.Run("cmd /c " + tmpfile, 7, true);
        shell = null;

        // TODO: verify that files were actually optimized

        WScript.Echo("Attempted to optimize " + runstrings.length + " of " +
            files.length + " files");
    };

    optimg({ "imagePaths": argv(0), "delimiter": "*" });

}(WScript));