Question

I have a perl script that needs 2 arguments to be run. I am currently using Ubuntu and I managed to execute the perl script from terminal by changing directory to where the perl script exists and by writing

perl tool.pl config=../mydefault.config file=../Test

However, when I am trying to run the perl script from my java program (I am using eclipse), It always gives me the message Command Failure. This is the code :

Process process;
try {
    process = Runtime.getRuntime().exec("perl /home/Leen/Desktop/Tools/bin/tool.pl config=../mydefault.config file=../Test");
    process.waitFor();
    if(process.exitValue() == 0) {
        System.out.println("Command Successful");
    } else {
        System.out.println("Command Failure");
    }
} catch(Exception e) {
    System.out.println("Exception: "+ e.toString());
}

So please what is wrong in my code?

Answer 1

You should be separating the command from it’s arguments in the call to exec(), such as:

Runtime.getRuntime().exec(new String[] {"perl", "/home/Leen...", "config=...", "file=..."});

With what you currently have, Runtime is looked for a command literally named perl /home/Leen/Desktop..., spaces and all.

When you run the whole command from the Terminal, your shell is smart enough to realize that a space delimits the name of the command (perl) from the arguments that should be passed to it (/home/Leen/Desktop..., config=..., file=...). Runtime.exec() is not that smart.