Running Shell scripts through JAva

Question

Hi,
I tried to execute a Shell script through a Java program.
The code I used is as below:
import java.lang.*;
import java.io.*;
public class sys {
public static void main(String[] args) {
Runtime rt = Runtime.getRuntime();
String[] callAndArgs = { "chgpasswd" };
try {
Process child = rt.exec(callAndArgs);
child.waitFor();
System.out.println("Process exit code is: " + child.exitValue());
catch(IOException e) {
System.err.println( "IOException starting process!");
catch(InterruptedException e) {
System.err.println( "Interrupted waiting for process!");
The "chgpasswd" shell script calls the "passwd" command of Unix.
It threw out an IO exception.
Then I gave the parameter as "./chgpasswd". It now gave an exit value of 255.
The "chgpasswd" script exists in the same directory as the .class file.
I checkd up the exit code reference...it says exit value of 255 could mean as exit code out of range........an exit code > 255....which unfortunately has no documentation, I guess.
Can you help ?

Answer 1

This is on a Unix platform, correct? Assuming so...
If I remember correctly, exit codes can be greater than 255. To get the real exit code equates to something like: exitcode & 512 to obtain the real exit code.
Make sure "chgpasswd" shell script has the execute permissions set. Additionally, make sure that the first line of the script (the magic line) has the appropriate shell/interpreter to execute specified. For example, if "chgpasswd" were a Bourne (sh) script, the first like would be:
#!/bin/shFor perl, it may be something like:
#!/usr/bin/perlIt needs to be the absolute path to the shell/interpreter is the point.