(WSH) file timestamp manipulation utility [revised version]

touch.js

// touch.js --- file timestamp manipulation utility (like *nix touch)
// (c) Copyright 2012, Ji Han (hanji <at> outlook <dot> com)
// you are free to distribute it under the BSD license.

(function(){

if (WScript.Arguments.Length == 0){
	// this script works for files, but not folders. (you need win32api to do that.)
	// plus, there's no '-a' or '-m' options; it only touches the mtime.
	WScript.Echo('touch [-c] [-r <reference_file> | -t <timestamp>] <files>');
	WScript.Quit(1);
}

var convertDateToModifyDate = function(d){
	return (d.getMonth() + 1) + '/' + d.getDate() + '/' + d.getFullYear()
		+ ' ' + ((d.getHours() + 11) % 12 + 1) + ':' + ('00' + d.getMinutes()).slice(-2) + ':' + ('00' + d.getSeconds()).slice(-2)
		+ ' ' + (d.getHours() < 12 && 'AM' || 'PM');
}

// parse string '[[CC]YY]MMDDhhmm[.SS]' as date and time
var parseTimestampString = function(s){
	var a, b, c;
	if (!(a = s.match(/^(\d+)(\.\d+)?$/))){ return null } // a[1]: CCYYMMDDhhmm, a[2]: .SS or undefined
	if (!(b = a[1].match(/^(\d{4}|\d{2})?(\d{8})$/))){ return null } // b[1]: CCYY or undefined, b[2]: MMDDhhmm
	c = b[2].match(/../g); // c[0]: MM, c[1]: DD, c[2]: hh, c[3]: mm
	var x = (new Date()).getFullYear();
	// 'if (b[1] === undefined)' should have worked. but... it is broken.
	// 'parseInt(undefined)' would yield NaN, which evaluates to false in an 'if' clause.
	var y = parseInt(b[1], 10);  
	if (!y){ y = x } else if (y < 100){ y = x - x % 100 + y }
	// Gotcha: must specify radix 10, otherwise '09' would be parsed as zero.
	var m = parseInt(c[0], 10), d = parseInt(c[1], 10), h = parseInt(c[2], 10);
	return m + '/' + d + '/' + y
		+ ' ' + ((h + 11) % 12 + 1) + ':' + c[3] + ':' + (a[2] || '00').slice(-2)
		+ ' ' + (h < 12 && 'AM' || 'PM');
}

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

var modifyDateOfFolderItem = function(it){
	return shell.NameSpace(fso.GetParentFolderName(fso.GetAbsolutePathName(it))).ParseName(fso.GetFileName(it)).ModifyDate;
}

var args = [];
var options = {};

for (var i = 0; i < WScript.Arguments.Length; ++i){
	if (WScript.Arguments(i).substring(0, 1) != '-'){
		args.push(WScript.Arguments(i));
	} else if (WScript.Arguments(i) == '-r'){
		options['reference_file'] = WScript.Arguments(++i);
	} else if (WScript.Arguments(i) == '-t'){
		options['timestamp'] = WScript.Arguments(++i);
	} else if (WScript.Arguments(i) == '-c'){
		options['creative'] = false;
	} else if (WScript.Arguments(i) == '--'){
		continue;
	} else {
		WScript.Echo('invalid option \'' + WScript.Arguments(i) +'\'');
		WScript.Quit(1);
	}
}

var mTime;

if (options['timestamp']){
	mTime = parseTimestampString(options['timestamp']);
}
else if (options['reference_file']){
	var it = options['reference_file'];
	if (!(fso.FileExists(it) || fso.FolderExists(it))){
		WScript.Echo('reference file \'' + it +'\' not found.');
		WScript.Quit(1);
	}
	mTime = modifyDateOfFolderItem(it);
}
else {
	mTime = convertDateToModifyDate(new Date());
}

for (var i = 0; i < args.length; ++i){
	var it = args[i];
	if (!(fso.FileExists(it) || fso.FolderExists(it))){
		if (options['creative'] === false){
			WScript.Echo('file \'' + it +'\' not found.');
			continue;
		} else {
			fso.CreateTextFile(it);
		}
	}
	//modifyDateOfFolderItem(it) = mTime; //oops... not an lvalue.
	shell.NameSpace(fso.GetParentFolderName(fso.GetAbsolutePathName(it))).ParseName(fso.GetFileName(it)).ModifyDate = mTime;
}

})();