hi all, Can we call(run) unix commands through a java program? Plzz let me know.... Actually i want the commands like "ls" to run automatically when some event occurs & then i want to store its output in a file by redirecting it. if anybody knows any link or the solution...plzz tell me.. Thanx in advance....waiting 4 ur reply....

use the java.lang.Runtime's exec() method. this is documented at; http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Runtime.html As for redirecting output to a file i am having problems running commands with output redirection under Redhat Linux 9. The > symbol is not being interpreted correctly. For example ls > fred.txt results in an error message >: No such file or directory. A work around is to use a shell script or don't use redirection and read the commands stdout via your Java. It depends on what you ultimately want to do with the commands output. Below is a code example. Simply change the values of cmd and workDir to suit your situation. import java.io.File; import java.io.BufferedReader; import java.io.InputStreamReader; /** * @author wharfie * 2004-02-27 * Run a system command */ public class RunSystemCommand { public static void main(String args[]) { String s = null; // system command to run String cmd = "ls > fred.txt"; // set the working directory for the OS command processor File workDir = new File("/dir1/dir2"); try { Process p = Runtime.getRuntime().exec(cmd, null, workDir); int i = p.waitFor(); if (i == 0){ BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream())); // read the output from the command while ((s = stdInput.readLine()) != null) { System.out.println(s); } } else { BufferedReader stdErr = new BufferedReader(new InputStreamReader(p.getErrorStream())); // read the output from the command while ((s = stdErr.readLine()) != null) { System.out.println(s); } } } catch (Exception e) { System.out.println(e); } } }