Java File Attribute makeExecutable(File file)

Description

Attempt to make a file executable.

License

Open Source License

Parameter

Parameter	Description
file	file

Exception

Parameter	Description
IOException	on any error

Declaration

public static void makeExecutable(File file) throws IOException 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.io.ByteArrayOutputStream;
import java.io.File;

import java.io.IOException;
import java.io.InputStream;

import java.io.OutputStream;

public class Main {
    /**//from  w w w  . ja  va  2s . com
     * Default buffer size for stream utility methods
     */
    public static int BUFFER_SIZE = 8192;

    /**
     * Attempt to make a file executable. Only current works on systems that
     * have the <b>chmod</b> command available.
     * 
     * @param file file
     * @throws IOException on any error
     */
    public static void makeExecutable(File file) throws IOException {
        Process p = Runtime.getRuntime().exec(new String[] { "chmod", "ug+rx", file.getAbsolutePath() });
        try {
            copy(p.getErrorStream(), new ByteArrayOutputStream());
        } finally {
            try {
                if (p.waitFor() != 0) {
                    throw new IOException("Failed to set execute permission. Return code " + p.exitValue() + ".");
                }
            } catch (InterruptedException e) {
            }
        }

    }

    /**
     * Copy from an input stream to an output stream. It is up to the caller to
     * close the streams.
     * 
     * @param in input stream
     * @param out output stream
     * @throws IOException on any error
     */
    public static void copy(InputStream in, OutputStream out) throws IOException {
        copy(in, out, -1);
    }

    /**
     * Copy the specified number of bytes from an input stream to an output
     * stream. It is up to the caller to close the streams.
     * 
     * @param in input stream
     * @param out output stream
     * @param count number of bytes to copy
     * @throws IOException on any error
     */
    public static void copy(InputStream in, OutputStream out, long count) throws IOException {
        copy(in, out, count, BUFFER_SIZE);
    }

    /**
     * Copy the specified number of bytes from an input stream to an output
     * stream. It is up to the caller to close the streams.
     * 
     * @param in input stream
     * @param out output stream
     * @param count number of bytes to copy
     * @param bufferSize buffer size
     * @throws IOException on any error
     */
    public static void copy(InputStream in, OutputStream out, long count, int bufferSize) throws IOException {
        byte buffer[] = new byte[bufferSize];
        int i = bufferSize;
        if (count >= 0) {
            while (count > 0) {
                if (count < bufferSize)
                    i = in.read(buffer, 0, (int) count);
                else
                    i = in.read(buffer, 0, bufferSize);

                if (i == -1)
                    break;

                count -= i;
                out.write(buffer, 0, i);
            }
        } else {
            while (true) {
                i = in.read(buffer, 0, bufferSize);
                if (i < 0)
                    break;
                out.write(buffer, 0, i);
            }
        }
    }
}

Related

1. javaExecutable(File jre)
2. launchExecutable(String executable, List args, Preferences preferences)
3. makeCurrentDirectoryThatOfExecutable(String executable)
4. makeExecutable(File file)
5. makeExecutable(File file)
6. makeExecutable(File file)
7. makeExecutable(File target)
8. makeExecutable(String path)
9. parallel(ExecutorService executor, Collection> tasks)