Runtime.exec() question

[Cuneyt Taskiran]

Hi,
I am trying to run the VideoLAN media player from withing my program using:

    
System.out.println("starting video capture");
 
String[] cmd = { "vlc", 
  "pvr:///dev/video0",
  "--sout'=#duplicate{dst=std{access=file,mux=ps,dst=/home/workspace/from_eclipse.mpg}}'"
};
Process p = rt.exec( cmd );
 
String line;
BufferedReader input = new BufferedReader(new InputStreamReader(p.getErrorStream()));

while ((line = input.readLine()) != null) {
System.out.println(line);
}
input.close();
 
try {
Thread.sleep(7000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("stopping video capture");
p.destroy();
 

When this runs, VLC gives me an error for the second argument (the sout one). However, when I copy and paste the same command to the command line it works well. What am I missing? Should I escape singe quotes?

Thanks for the help,

C

[Campbell Ritchie]

Don't know. But nobody should even think of going near Runtime.exec() without reading the classic paper by Michael Daconta. Google for "when Runtime.exec() won't".
Using a destroy() method looks suspect, even though that destroy() method isn't deprecated.
The ProcessBuilder class may make it easier to run a Process.

[Carey Evans]

When using Runtime.exec() (or ProcessBuilder) you do not need to add any extra quoting to the command line arguments, like the single quotes in the --sout line. Try taking them out, then read Michael Daconta's paper.

[Cuneyt Taskiran]

QUESTION CLOSED
Getting rid of the single quotes in the --sout part of the command solved the problem.

I agree that destroy() is not an elegant way to terminate the process, will look into ProcessBuilder.