Running a bash shell script in java
java, shell
Solution
You should use the returned `Process` to get the result.
`Runtime#exec` executes the command as a separate process and returns an object of type `Process`. You should call `Process#waitFor` so that your program waits until the new process finishes. Then, you can invoke `Process.html#getOutputStream()` on the returned `Process` object to inspect the output of the executed command.
An alternative way of creating a process is to use `ProcessBuilder`.
Process p = new ProcessBuilder("myCommand", "myArg").start();
With a `ProcessBuilder`, you list the arguments of the command as separate arguments.
See Difference between ProcessBuilder and Runtime.exec() and ProcessBuilder vs Runtime.exec() to learn more about the differences between `Runtime#exec` and `ProcessBuilder#start`.
Problem
I want to run a shell script from my program below but it doesn't seem to do anything. I've run the same command directly in the linux terminal and it works fine so I'm guessing it's my java code. As you can see, I was first writing the command to the shell script using a PrintWriter but I expect that this would not effect the running of the shell script itself. Any help would be appreciated! ``` public static void main(String[] args) { // TODO Auto-generated method stub String nfdump = "nfdump -o csv -r /home/shane/Documents/nfdump/nfcapd.201211211526>blank.txt"; try { FileWriter fw = new FileWriter("/home/shane/Documents/script.sh"); PrintWriter pw = new PrintWriter(fw); pw.println("#!/bin/bash"); pw.println(nfdump); pw.close(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } Process proc = null; try { proc = Runtime.getRuntime().exec("sh /home/shane/Documents/script.sh"); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } ```