Execute program from another directory using Runtime.exec()

Question

I want to execute a program (System.getenv("appdata") + "ffmpeg"). I also want to be able get a process or something that could get me the consle output. I have tried "cmd /C " + System.getenv("appdata") + "ffmpeg" before and it didn't seem to work. Any help is appreciated!

Here is some code:

Process p = exec(testFFMpeg);
    int ex = -1;
    try {
        ex = p.waitFor();
    } catch (InterruptedException e) {
        e.printStackTrace();
        CrashHandler.reportCrash("FFMpeg", "Unable to test FFMpeg", "start up with more permissions");
    }

    if(ex == 0){
        System.out.println("Normal execution, exit value: " + ex);
        BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
        String line = null;

        do{
            try {
                line = br.readLine();
                System.out.println(line);
            } catch (IOException e) {
                e.printStackTrace();
                CrashHandler.reportCrash("FFMpeg", "Unable to test FFMpeg", "start up with more permissions");
            }
        }while(line != null);
    }else{
        System.out.println("Execution exit value: " + ex);
    }
}

private static Process exec(String[] cmd){
    try {
        return Runtime.getRuntime().exec(cmd);
    } catch (IOException e) {
        e.printStackTrace();
        CrashHandler.reportCrash("FFMpeg", "Unable to test FFMpeg", "start up with more permissions");
    }

The exact location of the file is: `System.getenv("appdata") + "\VinVid\" + "ffmpeg.exe".

Please look at docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html — Mehul Rathod
– Mehul Rathod, Commented Oct 6, 2013 at 3:16
One thing is that how would I get the output instead of saving to a file. — APerson
– APerson, Commented Oct 6, 2013 at 3:28

APerson · Accepted Answer · 2013-10-06 04:21:16Z

1

I figured it out. The output was going to the error stream, not the inputStream.

answered Oct 6, 2013 at 4:21

APerson

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Comments

Evgeniy Dorofeev · Accepted Answer · 2013-10-06 03:29:47Z

0

You are missing path separator, try this

System.getenv("appdata") + "\\ffmpeg"

answered Oct 6, 2013 at 3:29

Evgeniy Dorofeev

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2 Comments

Aneesh Over a year ago

can you tell us what error you are getting? Did you add the extension .exe to ffmpeg?

APerson Over a year ago

I tried Aneesh's answer but added p.waitFor(); right after creating the BufferedReader and it simply says nothing.

Aneesh · Accepted Answer · 2013-10-06 03:46:02Z

0

In your code change this line line = br.readLine(); to line += br.readLine(); This is how you run a windows process in java. I don't know what output you want. If your asking to print the output of the process you ran, this code helps :

String line;
String pidInfo ="";

Process p =Runtime.getRuntime().exec(System.getenv("appdata") +"ffmpeg.exe");

BufferedReader input =  new BufferedReader(new InputStreamReader(p.getInputStream()));

while ((line = input.readLine()) != null) {
    pidInfo+=line; 
}

input.close();

System.out.println(pidInfo);

edited Oct 6, 2013 at 3:46

answered Oct 6, 2013 at 3:35

Aneesh

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4 Comments

APerson Over a year ago

There is simply no output

Aneesh Over a year ago

Maybe your process doesn't give any outputs. Replace your cmd with this System.getenv("windir") +"\\system32\\"+"tasklist.exe" and try to see if any output comes

APerson Over a year ago

it just stops the app and says nothing same with System.getenv("windir") +"\\system32\\"+"cmd.exe" If I run ffmpeg from cmd it throws out a bunch of output

APerson Over a year ago

I'll try using apache commons exec

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