How to run a script from Java

Question

I have a script, which is test.sh on Ubuntu. I want to run it from Java. I know I have to use Runtime.getRuntime().exec();

Don't I have to fill the exec parenthesis with the location of test.sh? I am typing /home/main/ss/test.sh

I do not get any error messages but when I searched the folder, I saw that script did not work. How can I fix it?

Actually my script works correct, but when I try to work it from java, I do not get any response — Burak Keceli, Feb 06 '12 at 21:18
I mean that when I work it on console, I get the right result — Burak Keceli, Feb 06 '12 at 21:20
have you checked that java finds the file? something like new File("...test.sh").exists()? — Yashima, Feb 06 '12 at 21:24
yes I check it, it can find test.sh Do I wrong about thinking that there must be a location in the paranthesis of exec? — Burak Keceli, Feb 06 '12 at 21:28
probably duplicate http://stackoverflow.com/questions/525212/how-to-run-unix-shell-script-from-java-code — chahuistle, Feb 06 '12 at 21:36
Because it is supposed to delete a folder in the same folder, but after running java program, it is still there. — Burak Keceli, Feb 07 '12 at 08:57

score 1 · Answer 1 · answered Feb 06 '12 at 21:18

1

You should really look at Process Builder. It is really built for this kind of thing.

 ProcessBuilder pb = new ProcessBuilder("myshellScript.sh", "myArg1", "myArg2");
 Map<String, String> env = pb.environment();
 env.put("VAR1", "myValue");
 env.remove("OTHERVAR");
 env.put("VAR2", env.get("VAR1") + "suffix");
 pb.directory(new File("myDir"));
 Process p = pb.start();

answered Feb 06 '12 at 21:18

Sapan Diwakar

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But I do not understand how this can work. Is this just an example? – Burak Keceli Feb 06 '12 at 21:24
You can put the path to your `sh` file in place of `myshellScript.sh` and arguments (if any) after that. – Sapan Diwakar Feb 06 '12 at 21:36
I do not give any argument. For example, if I write these on java, is it gonna work? ProcessBuilder pb = new ProcessBuilder("/home/myshellScript.sh"); Map env = pb.environment(); env.put("VAR1", "myValue"); env.remove("OTHERVAR"); env.put("VAR2", env.get("VAR1") + "suffix"); pb.directory(new File("myDir")); Process p = pb.start(); – Burak Keceli Feb 06 '12 at 21:59

score 0 · Answer 2 · answered Feb 06 '12 at 21:34

0

Did you try to call your script directly, or did you specify a shell to use? You may need to specify the shell on your exec call if it's not specified (and processed) from the first line of the script.

answered Feb 06 '12 at 21:34

Brian Knoblauch

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I have tried to call my script directly. I have written just this : Runtime.getRuntime().exec("/home/main/ss/test.sh"); – Burak Keceli Feb 06 '12 at 21:48
What shell is it written for? You should probably be doing something similar (but could be different depending on your shell/os/environment requirements) to: Runtime.getRuntime().exec("/bin/bash /home/main/ss/test.sh"); – Brian Knoblauch Feb 06 '12 at 21:50
If there is a shebang in the script (`#!/bin/bash`), you don't need to specify the shell, to pick the right one, because the kernel evaluates the shebang. Is there such a shebang? – user unknown Feb 07 '12 at 06:16

score 0 · Answer 3 · answered Feb 07 '12 at 01:24

From looking at your description, how you conclude the script didn't work:

I do not get any error messages but when I searched the folder, I saw that script did not work. How can I fix it?

I conclude, the script creates a new file, and there is none, after starting from Java.

Maybe you assume, that the output of the script will, if sent to the current directory, end in the directory of the script, not in the directory where you started your Java application.

This might be the Desktop, if you start your class from the UI with an Icon as starter, it might be your home or project dir, if you compile the class from hand, or a directory, set up by your IDE, if you develop with eclipse or the like.

If your script writes to an absolute path like /tmp/script.out, you could verify fast, whether this might be your issue.

How to run a script from Java

3 Answers3

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