com.darwinsys.lang.ExecAndPrint Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of darwinsys-api Show documentation

Ian Darwin's assorted Java stuff, assembled as an API.

There is a newer version: 1.8.0

package com.darwinsys.lang;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;

import com.darwinsys.io.FileIO;

/**
 * ExecAndPrint runs a program using Runtime.exec(),
 * read the program's output, and returns its exit status.
 */
public class ExecAndPrint {

	/** Need a Runtime object for any of these methods */
	protected final static Runtime r = Runtime.getRuntime();

	/** Run the command given as a String, printing its output to System.out */
	public static int run(String cmd) throws IOException { 
		return run(cmd, new OutputStreamWriter(System.out));
	}

	/** Run the command given as a String, print its output to "out" */
	public static int run(String cmd, Writer out) throws IOException {
		
		Process p = r.exec(cmd);

		FileIO.copyFile(new InputStreamReader(p.getInputStream()), out, true);
		try {
			p.waitFor();	// wait for process to complete
		} catch (InterruptedException e) {
			return -1;
		}
		return p.exitValue();
	}

	/** Run the command given as a String[], print its output to System.out */
	public static int run(String[] cmd) throws IOException { 
		return run(cmd, new OutputStreamWriter(System.out));
	}

	/** Run the command given as a String[], print its output to "out" */
	public static int run(String[] cmd, Writer out) throws IOException {
		
		Process p = r.exec(cmd);

		FileIO.copyFile(new InputStreamReader(p.getInputStream()), out, true);

		try {
			p.waitFor();	// wait for process to complete
		} catch (InterruptedException e) {
			return -1;
		}
		return p.exitValue();
	}
}