Running bash script from Processing

JeffThomp..

Running bash script from Processing

in Integration and Hardware • 2 years ago

Hi all, I'm looking to run a very simple bash script from Processing - in this case to combine mp3s, fix their header data, and save. I have it working with no issue from Terminal but can't get it to work in Processing.

I've tried some of the options (the open() help file and http://processing.org/discourse/yabb2/YaBB.pl?num=1239227478) but while I don't get errors, nothing happens either.

My Processing code (currently doesn't do anything except attempt to run the script):

import java.io.*;

void setup() {

// nope, doesn't work...
open("combineMP3s.sh");      // locally stored in the sketch folder

// not this either!
String fullPath = "/Users/jeffthompson/Documents/Processing/CombineMP3_CommandLine/combineMP3s.sh";
try {
    Runtime rt = Runtime.getRuntime();
    Process pr = rt.exec(fullPath);
}
catch (IOException e) {
    e.printStackTrace();
}

}

And my script, if it's of any use. It requires two external libraries: mp3cat ( http://tomclegg.net/mp3cat) and id3cp ( http://www.linuxfromscratch.org/blfs/view/cvs/multimedia/id3lib.html), but at least shows what's happening.

#!/bin/bash

clear

echo "Combining files..."
cat 01.mp3 02.mp3 03.mp3 04.mp3 05.mp3 06.mp3 07.mp3 08.mp3 09.mp3 10.mp3 11.mp3 12.mp3 13.mp3 | mp3cat - - > combined.mp3

echo
echo "Updating metadata..."
id3cp 01.mp3 combined.mp3

echo "FINISHED!"

I'm not very familiar with bash scripting or running anything from the command-line, so this might be something really simple...

Thanks all!

Replies(3)

PhiLho

Re: Running bash script from Processing

2 years ago

Since your bash script doesn't take any parameter, do you really need to run it from Processing? Or are you acting on generated files?

Anyway, I don't have much experience in shell script either, even less launching them from a program, but perhaps you should launch the shell interpreter, giving it the shell to run. Sometime it works better than expecting the system to do the right thing.
For example, in Windows, instead of open("foo.bat"), we have to do open("cmd /c foo.bat")

JeffThomp..

Re: Running bash script from Processing

2 years ago

Hi phi.lo, thanks for the response. I left out all the Processing-based stuff for clarity's sake, but I would like to be able to run it automatically from Processing. The reason for using the bash script is speed and ease of handling mp3's (including writing new metadatato the header) without needing an audio driver.

I should have mentioned that I'm on a Mac - it appears that mp3cat/id3cp will not compile on Windows.

With a little experimentation, I've got this to open the script when using a full path:

open("/Users/jeffthompson/Documents/Processing/CombineMP3_CommandLine/data/combineMP3s.sh");

However, it opens in Final Cut!

JeffThomp..

Re: Running bash script from Processing

2 years ago

I know this thread has been silent for a while, but since I've come up with a solution I thought it might help others later. Here's my annotated solution:

/*
* RUN UNIX COMMANDS IN PROCESSING
* Jeff Thompson
* Adapted and annotated from code by Wharfie
* http://www.computing.net/answers/unix/run-unix-command-thr-java-program-/5887.html
* July 2011
*
* Runs Unix commands from within Processing. This can be *super* helpful for
* doing complex operations on folders such as copying or compressing multiple
* files. A simple command can make quick work of what would otherwise be a
* cumbersome task in Processing and will likely be much quicker than any Java
* implementation of the same process.
*
* You will likely need to specify the full path where you want to work, unless your
* location is relative to your sketch. For example: /Users/jeffthompson/Desktop
*
* Suggestions to try:
*   whoami                            prints username currently logged on
*   ls                                this lists all files in the particular location
*   wc -w filename.extension          this counts words in a particular file
*   cp sourcefile.ext destfile.txt    makes a copy of a file to a new one
*   ./yourBashScript.sh               run a bash script (allowing nested and more complex commands)
*
* For more ideas, look at the excellent SS64 site: http://ss64.com/bash
*
* www.jeffreythompson.org
*/

void setup() {

// what command to run
String commandToRun = "whoami";
// String commandToRun = "ls";
// String commandToRun = "wc -w sourcefile.extension";
// String commandToRun = "cp sourcefile.extension destinationfile.extension";
// String commandToRun = "./yourBashScript.sh";

File workingDir = new File("/Users/jeffthompson/Documents/Processing/RunUnixCommands/");   // where to do it - should be full path
String returnedValues;                                                                     // value to return any results

// give us some info:
println("Running command: " + commandToRun);
println("Location:        " + workingDir);
println("---------------------------------------------\n");

// run the command!
try {

    // complicated! basically, we have to load the exec command within Java's Runtime
    // exec asks for 1. command to run, 2. null which essentially tells Processing to
    // inherit the environment settings from the current setup (I am a bit confused on
    // this so it seems best to leave it), and 3. location to work (full path is best)
    Process p = Runtime.getRuntime().exec(commandToRun, null, workingDir);

    // variable to check if we've received confirmation of the command
    int i = p.waitFor();

    // if we have an output, print to screen
    if (i == 0) {

      // BufferedReader used to get values back from the command
      BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));

      // read the output from the command
      while ( (returnedValues = stdInput.readLine ()) != null) {
        println(returnedValues);
      }
    }

    // if there are any error messages but we can still get an output, they print here
    else {
      BufferedReader stdErr = new BufferedReader(new InputStreamReader(p.getErrorStream()));

      // if something is returned (ie: not null) print the result
      while ( (returnedValues = stdErr.readLine ()) != null) {
        println(returnedValues);
      }
    }
}

// if there is an error, let us know
catch (Exception e) {
    println("Error running command!");
    println(e);
}

// when done running command, quit
println("\n---------------------------------------------");
println("DONE!");
exit();
}

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