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I have a Java program that runs a batch file on Windows with Runtime.getRuntime().exec() using the following command:

cmd /C start "Title" "C:\Folder\file.bat"

The Java program ends quickly since cmd /C carries out the command and then terminates (1) and start "Title" "C:\Folder\file.bat" starts the batch script (2). Thus the process (the batch file) will continue running independently.

Now, suppose that I have an shell script (e.g. file.sh), which I want to launch from Java and has a similar behavior. How could it be the equivalent command (3) in Linux?

Notes

  1. See CMD.exe (Command Shell) | Windows CMD | SS64.com
  2. See Start - Start a program | Windows CMD | SS64.com
  3. The title ("Title") is not required.
Paul Vargas
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  • we have SO MANY ways to execute a file in linux. but perhaps sharing the contents of your .bat file would be more lucrative. the path, C:\ doesnt exist, youll change that to the path in linux. ~/ – j0h Mar 25 '15 at 06:15
  • @j0h I have edited the question. The content of the script can be anything. However, I am interested in the command to launch it with a similar behavior. – Paul Vargas Mar 25 '15 at 06:53
  • The question effectively is a duplicate of this: http://askubuntu.com/q/38661/295286 Once bounty expires, it should be voted to be closed – Sergiy Kolodyazhnyy Apr 04 '17 at 12:32
  • @SergiyKolodyazhnyy - the item you link is about running scripts from the desktop. OP asks about launching processes from within Java. Not a duplicate? – taifwa Apr 05 '17 at 22:12
  • @taifwa OP knows how to launch process from Java program - they already mention `Runtime.getRuntime().exec()`, and Java being cross-platform language would use same method to launch a program. The post isn't about running scripts form desktop either - it's running scripts in general, and the key to that making script executable with `chmod +x` and giving path to script or at least having script live in one of the directories that belong to `PATH` variable. Whether or not it's form Java is irrelevant. These steps are required – Sergiy Kolodyazhnyy Apr 05 '17 at 22:21

4 Answers4

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The way to launch a script is to give its path:

/path/to/script.sh

To have it continue if the parent process exits, you can just launch it in the background by appending &:

/path/to/script.sh &

So, if you have, for example, one script calling another like so:

#!/bin/bash
script2.sh &

You could run script1.sh which will call script2.sh and, because it is sent to the background, exit immediately.

terdon
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1

You have many options, the more interesting are these:

  • If it's for Ubuntu, you can use gnome-terminal:

    gnome-terminal -c "/home/$USER/file.sh" -t "Title"

    or:

    gnome-terminal -- "/home/$USER/file.sh" -t "Title"

  • If do you want to make it compatible with most linux, you can use xterm:

    xterm -T "Title" -e "/home/$USER/file.sh"

The path is /home/$USER/file.sh (Windows 7 equivalent: C:\Users\%UserProfile%\file.bat)

The file.sh contents may be something like this:

#!/bin/bash

echo "In a World without Walls nor Fences, the people don't need Windows and Gates"
sleep 2
BeastOfCaerbannog
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0x2b3bfa0
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1

Various ways to execute a script in Linux: my arbitrary script name is foo.bat

ex1:$bash foo.bat

ex2:$./foo.bat

ex3:$echo $(~/Desktop/foo.bat)

ex4:`~/Desktop/foo.bat`

ex5:$ /path/to/shell/script/foo.bat

ex1: this is is just a regular file at this point, we execute it with bash
ex2: we have marked foo.bat as executable. ($chmod +x foo.bat)
ex3: Command substitution 
ex4: execute using "``"
ex5: we us the path to the executable.

These are the most common. I would avoid calling things like gnome-terminal, and xterm. These are less common shells compared to things like bash, and sh. For example I use Ubuntu mate. I have neither xterm nor gnome-terminal. But, I do have bash, and sh. as does nearly ever other person running Linux / mac osx.

You may appreciate this tutorial on script execution here

the script foo.bat does this:

$ ./foo.bat
Having a bash ./foo.bat

where its contents are:

$ cat foo.bat 
#!/bin/bash
echo -e "Having a bash" $0

I think the use of $0 can give you the title functionality you may desire. Many more possibilities exist.

j0h
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    gnome-terminal and xterm are not shells themselves, rather they're terminal emulators which run a shell. bash is a shell. zsh is a shell. ksh is a shell. – hanetzer Mar 25 '15 at 14:52
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As I understand, you want to run an external command from within Java, and have the Java process continue (asynchronously) whilst that external command continues to run too?

Here's a little test I whipped up:

[tai@flenux runproc ] $ ls
filecreator.sh  ProcRunner.class  ProcRunner.java

[tai@flenux runproc ] $ cat filecreator.sh 
touch newfile

[tai@flenux runproc ] $ cat ProcRunner.java 

public class ProcRunner {
    public static void main(String[] args) {
        try {
            Runtime.getRuntime().exec(args);
            Thread.sleep(2000);
            System.out.println("Done");
        } catch(Exception e) {
            System.err.println(e.toString() );
        }
    }
}

[tai@flenux runproc ] $ java ProcRunner bash filecreator.sh 
Done

[tai@flenux runproc ] $ ls
filecreator.sh  newfile  ProcRunner.class  ProcRunner.java

[tai@flenux runproc ] $

Java successfully execs the program (which simply creates the "newfile" file) ; it also continues on its own merry way to print the Done message after calling the exec.

If you wanted a terminal window to open too, prefix the call string

Runtime.getRuntime().exec(["gnome-terminal", "-e"]+args);

So to answer your question, it looks like you would just call the method you specified. Are you getting a different behaviour?

taifwa
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