External dos command

[Andy Sabb]

hi java jedis, I've got a little problem with launching external applications (in windows) that even after looking around for explanations didn't get solved...
When I run something like:
try
{Runtime rt = Runtime.getRuntime();
Process pc = rt.exec("C:/Windows/command.com /c dir /p");
}
catch(IOException ioe){}
it seems I'm not able to run dos mode applications or dos commands. Everything remains as is with no changes, but if I try running write.exe or the like everything is ok. Any ideas ?
Thanks !
Andy

[Cindy Glass]

Try using something like this:
Runtime.getRuntime().exec("cmd /K start run.bat");
Runtime.getRuntime().exec("cmd /K del run.bat");
Only the older versions of Windows still use "command".
Also here is a good article about exec http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html

[Andy Sabb]

Ehm, yep thanks for your help, that article is really uhm (long ? ) neat.
But trying "cmd /k" doesn't work and I still (maybe I'm just a bit dumb) can't make it work as I intended to...
I'm sorry to bother you more, but I'm writing a Java MAME Frontend (bad idea ? found that too late ). Everything is perfect and in place (and I even like it), apart from a tiny inconvenient... I can't run the emulator ! . The command string would be "c:/games/mame/mame.exe " + romname, but when I call it, it just hangs ! Thanks anyway if you have time to reply...
Cheers
Andy

[Cindy Glass]

If you are just trying to start an executable, you do not need cmd or command. You just name the executable and the input parameter.
Your input choices include feeding in ONE stringl, or setting up some String arrays and feeding that it.

<font size=2.5>
class Test
{
    public static void main(String [] args) throws IOException
    {
                String romname = "deptdesc.txt";
                String inParam = "notepad.exe " + romname;
                Runtime.getRuntime().exec(inParam);
     }
}

[Nathan Pruett]

Cindy,

I've tried it myself... it works fine with programs that are made to run in windows, but programs that are made to run in DOS just hang...

For example, if you try running "ipconfig.exe" or "NetHack.exe" or other things made to run at the DOS prompt instead of textpad, notepad, or other programs made to run in a new window...

Puzzling...

-Nate

[Cindy Glass]

hmmm. . . . Must have something to do with the fact that we are starting a new process instead of just using the process that is controlling the dos window.
I'll have to poke into this.