Question

I am using the process class to run this command

/sdcard/file1.mpg /sdcar/file2.mpg > /sdcard/out.mpg

Here is how I am trying to do it:

Process processx = Runtime.getRuntime().exec(new String[] {"cat","/sdcard/file1.mpg /sdcard/file2.mpg > /sdcard/out.mpg" });

BufferedReader in = new BufferedReader(new InputStreamReader(processx.getInputStream()));

String line = null;
while ((line = in.readLine()) != null) {
      System.out.println(line);
}

// Waits for the command to finish.
processx.waitFor();

The command works from terminal but not when I try the above, can anyone see why?

Answer 1

Redirection (>) is not the OS feature. This is a feature of shell. To make it working from java you have to run something like the following:

/bin/sh yourcommand > yourfile

i.e. in your case:

/bin/sh cat /sdcard/file1.mpg /sdcard/file2.mpg > /sdcard/out.mpg

BUT could you please explain me why are you doeing this? Do you understand that this command is exact equivalent of cp /sdcard/file1.mpg /sdcard/file2.mpg /sdcard/out.mpg that can be coded in pure java without running any command line? Unless you have special reasons go on it! Write pure java code when it is possible. It is easier to debug, support and maintain.