read stdout of a commandline prog

[Ido Daisuke]

For example, if I do this:

$ echo "foo\nbar\nbaz"

How to get the java prog to read these lines?

[Luigi Plinge]

I'm by no means an expert on this, and it's probably not the best way, but how about getting your command line prog to call "java MyClass foo\nbar\nbaz" then deal with them as command line arguments?

[Paul Clapham]

You pipe them to the stdin of your Java class:

$ echo "foo\nbar\nbaz" | java yourClass

and write your class to read the data from System.in.

[Stephan van Hulst]

Yes, this is more OS specific, and not really Java related. Assuming you are using Unix, in Windows you can pipe commands using | as well.

[Srinivas Kalvala]

Below class reads the input from standard input stream. Please let me know if it is not what you are looking for ...

package com.test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class CmdTest {
	public static void main(String[] args) {
		BufferedReader bufferedReader = new BufferedReader(
				new InputStreamReader(System.in));
		System.out.println("Reading data .... ");
		String data;
		try {
			while((data = bufferedReader.readLine()) != null){
				System.out.println(data);
			}
			bufferedReader.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		
	}
}

Test:
echo 'Hello' | java -cp . com.test.CmdTest

Result:
Reading data ....
'Hello'

[Campbell Ritchie]

Welcome to the Ranch

This question is too difficult for "beginning" so I shall move it.