JS2BAT converter 2

Earlier to embed javascript codes into batch files the JS2BAT tool has ben implemented with batch features only. In this topic the same tool has been implemented in pure javascript. As opposed to the previous version the present one is the more functional and has optional parmeters. Previously the js2bat.js script has been implemented in javascript. After that it has been converted to the js2bat.bat batch script by itself with the following command:

cscript js2bat.js js2bat.js

So this script consists of two parts - the prolog, presenting of batch script invoking itself, and the main code in javascript. In order to show colorized codes by the syntax highlighter this script has been splitted into two parts. In reality both have to be located within the single file.

@set @x=0 /*
@set @x=
@ cscript /nologo /e:javascript "%0" %*
@goto:eof */

// Display the minimal usage screen
if ( ! WScript.FullName.match(/cscript/i) || WScript.Arguments.Named.Exists('H') ) {
    WScript.Echo([
        'Usage:',
        '\tJS2BAT [/H]',
        '\tJS2BAT [file] [/W] [/A:"string"]',
    ].join('\n'));

    WScript.Quit();
}

// Define the script host to be launched (WSCRIPT or CSCRIPT)
var host = WScript.Arguments.Named.Exists('W') 
    ? 'wscript'
    : 'cscript';

// Additional arguments for the script host
var args = WScript.Arguments.Named('A') 
    ? WScript.Arguments.Named.item('A') 
    : '/nologo';

var prolog = [
    '@set @x=0 /*', 
    '@set @x=', 
    ['@', host, args, '/e:javascript "%~dpnx0" %*'].join(' '), 
    '@goto:eof */', 
    ''
].join('\n');

var e;
var lines;

if ( WScript.Arguments.Unnamed.length == 0 ) {
    try {
        lines = WScript.StdIn.ReadAll();
    } catch (e) {
        lines = '';
    }
    WScript.StdOut.Write(prolog + lines);

    WScript.Quit();
}

var fso = new ActiveXObject('Scripting.FileSystemObject');

for (var i = 0; i < WScript.Arguments.Unnamed.length; i++) {
    var j_name = WScript.Arguments.Unnamed.item(i);
    var b_name = j_name.replace(/\.js/, '.bat');

    var f, h, e;

    try {
        f = fso.GetFile(j_name);
        h = f.OpenAsTextStream();
        lines = h.ReadAll();
        h.Close();
    } catch (e) {
        // Error 62 - Input past end of file
        // It means try to read an empty file
        if ( (e.number & 0xffff) != 62 ) {
            WScript.Echo('"' + j_name + '" not found.');
            WScript.Quit(1);
        }
        lines = '';
    }

    try {
        h = fso.OpenTextFile(b_name, 2, true);
        h.Write(prolog + lines);
        h.Close();
    } catch (e) {
        WScript.Echo('Cannot write to the file "' + j_name + '".');
        WScript.Quit(1);
    }
}

WScript.Quit();