Running batch file with JScript in HTA

Question

I am creating this HTA application with JScript that writes a BAT file and then opens it in cmd .

If I manually open the created BAT file from windows, it works as it should.
When I open it through my HTA, the file opens, but only echoes and pauses.

Please keep in mind that I am very new to programming.

Here is the JScript.

 // Write the Bat file // When run from HTA all I get is the "Echo Done" and "Pause" // When I run from Windows without HTA, all of it works. function writeBat() { var fso = new ActiveXObject("Scripting.FileSystemObject"); var s = fso.CreateTextFile("C:/test/test.bat"); s.WriteLine('@echo off'); s.WriteLine('set output=C:/test/new/'); s.WriteLine('FOR %%a in (*.mkv) DO ("C:/Program Files/MKVToolNix/mkvmerge.exe" -o "%output%%%~na.mkv" "%%a")'); s.WriteLine('echo Done.'); s.WriteLine('pause'); s.Close(); } // Run the Bat file. function runBat() { var MyObject = new ActiveXObject("wscript.shell"); MyObject.Run("C:/test/test.bat"); } 

Here is the batch file.

 @echo off set output=C:/test/new/ FOR %%a in (*.mkv) DO ( "C:/Program Files/MKVToolNix/mkvmerge.exe" -o "%output%%%~na.mkv" "%%a") echo Done. pause 

And HTML

 <form> <input type="button" value="Write Bat" onClick="writeBat()"> <input type="button" value="Run Bat" onClick="runBat()"> </form> 

Answer 1

Well, you found your answer. The HTA context is in another working directory from the script package context. You must have a batch of script cd or pushd up to "%~dp0" . This is pretty standard for batch scripts added to context menus, etc.

 s.WriteLine('pushd "%~dp0"'); 

... as you have already done, this is the right decision. You must also

 s.WriteLine('@echo off & setlocal'); 

... to limit the amount of variables in this batch script for the runtime of the batch script itself.

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But the main reason I'm posting an answer is to provide more information about the Chakra engine. Even with IE9, 10, 11, Edge, no matter what is installed, the Windows script Host supports a feature set as it existed in JScript 5.7. According to the MSDN documentation :

Starting with JScript 5.8, by default, the JScript scripting engine supports a set of language functions as it existed in version 5.7. This should maintain compatibility with earlier versions of the engine. To use the full language feature set in version 5.8, the Windows script host interface must call IActiveScriptProperty :: SetProperty .

What does this mean if you want to use methods in JScript 5.8 or later (for example, JSON, Object.keys , Array.prototype.forEach() methods, etc.), you basically need to write your own Windows script Host interpreter. But with HTA there is a simple hack that will allow you to use the features of IE9. Just add the following line to the top of your HTA file:

 <meta http-equiv="x-ua-compatible" content="IE=9" /> 

Before:

 <script> function get() { try { var json = JSON.parse(document.getElementById('json').value); alert(json.var1); } catch(e) { alert(e.message); } } </script> <textarea id="json">{"var1": "It works!"}</textarea> <button onclick="get()">Go!</button> 

Output:

'JSON' - undefined

After:

 <meta http-equiv="x-ua-compatible" content="IE=9" /> <script> function get() { try { var json = JSON.parse(document.getElementById('json').value); alert(json.var1); } catch(e) { alert(e.message); } } </script> <textarea id="json">{"var1": "It works!"}</textarea> <button onclick="get()">Go!</button> 

Output:

It works!

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However, this hack is not limited to HTA. You can also make it work on the JScript and JScript.NET console by creating a htmlfile COM object, entering the <meta> tag in it, and then copying the newly opened methods and objects to the current script host.