Question

i’m trying to execute a SOX command from java, but unfortunately its returning an error everytime. Every other SOX commands are working perfectly though!!
Here is the code :

class Simple {
    public static void main(String args[]) throws IOException, Exception {
        Process p;
        BufferedReader br;
        String co = "sox speech_16.wav -p pad 0 2.5 | sox - -m speech_16.wav speech_output.wav";
        p = Runtime.getRuntime().exec(co);
        br = new BufferedReader(new InputStreamReader(p.getInputStream()));
            int returnCode = p.waitFor();
        System.out.println("reurn code : "+returnCode);         
    }
}

When I’m executing the same sox command in terminal, its working fine. I really can’t understand what the problem is!! Is it because of the ‘|’ symbol??

Answer 1

The issue is that Runtime.exec() does not understand shell concepts such as “|”. Instead try:

Runtime.getRuntime().exec("/bin/sh", "-c", co);

The problem is that exec runs a binary directly without invoking the shell. The “|” character is only recognized by the shell, not by sox. The “-c” tells the shell to run a single command, and passes the entire command as the single argument.