/* * Copyright (c) 1995, 2004, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.misc; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintStream; import java.io.IOException; /** * This class implements a Berkeley uu character encoder. This encoder * was made famous by uuencode program. * * The basic character coding is algorithmic, taking 6 bits of binary * data and adding it to an ASCII ' ' (space) character. This converts * these six bits into a printable representation. Note that it depends * on the ASCII character encoding standard for english. Groups of three * bytes are converted into 4 characters by treating the three bytes * a four 6 bit groups, group 1 is byte 1's most significant six bits, * group 2 is byte 1's least significant two bits plus byte 2's four * most significant bits. etc. * * In this encoding, the buffer prefix is: *
 *     begin [mode] [filename]
 * 
* * This is followed by one or more lines of the form: *
 *      (len)(data)(data)(data) ...
 * 
* where (len) is the number of bytes on this line. Note that groupings * are always four characters, even if length is not a multiple of three * bytes. When less than three characters are encoded, the values of the * last remaining bytes is undefined and should be ignored. * * The last line of data in a uuencoded file is represented by a single * space character. This is translated by the decoding engine to a line * length of zero. This is immediately followed by a line which contains * the word 'end[newline]' * * @author Chuck McManis * @see CharacterEncoder * @see UUDecoder */ public class UUEncoder extends CharacterEncoder { /** * This name is stored in the begin line. */ private String bufferName; /** * Represents UNIX(tm) mode bits. Generally three octal digits representing * read, write, and execute permission of the owner, group owner, and * others. They should be interpreted as the bit groups: * (owner) (group) (others) * rwx rwx rwx (r = read, w = write, x = execute) * * By default these are set to 644 (UNIX rw-r--r-- permissions). */ private int mode; /** * Default - buffer begin line will be: *
     *  begin 644 encoder.buf
     * 
*/ public UUEncoder() { bufferName = "encoder.buf"; mode = 644; } /** * Specifies a name for the encoded buffer, begin line will be: *
     *  begin 644 [FNAME]
     * 
*/ public UUEncoder(String fname) { bufferName = fname; mode = 644; } /** * Specifies a name and mode for the encoded buffer, begin line will be: *
     *  begin [MODE] [FNAME]
     * 
*/ public UUEncoder(String fname, int newMode) { bufferName = fname; mode = newMode; } /** number of bytes per atom in uuencoding is 3 */ protected int bytesPerAtom() { return (3); } /** number of bytes per line in uuencoding is 45 */ protected int bytesPerLine() { return (45); } /** * encodeAtom - take three bytes and encodes them into 4 characters * If len is less than 3 then remaining bytes are filled with '1'. * This insures that the last line won't end in spaces and potentiallly * be truncated. */ protected void encodeAtom(OutputStream outStream, byte data[], int offset, int len) throws IOException { byte a, b = 1, c = 1; int c1, c2, c3, c4; a = data[offset]; if (len > 1) { b = data[offset+1]; } if (len > 2) { c = data[offset+2]; } c1 = (a >>> 2) & 0x3f; c2 = ((a << 4) & 0x30) | ((b >>> 4) & 0xf); c3 = ((b << 2) & 0x3c) | ((c >>> 6) & 0x3); c4 = c & 0x3f; outStream.write(c1 + ' '); outStream.write(c2 + ' '); outStream.write(c3 + ' '); outStream.write(c4 + ' '); return; } /** * Encode the line prefix which consists of the single character. The * lenght is added to the value of ' ' (32 decimal) and printed. */ protected void encodeLinePrefix(OutputStream outStream, int length) throws IOException { outStream.write((length & 0x3f) + ' '); } /** * The line suffix for uuencoded files is simply a new line. */ protected void encodeLineSuffix(OutputStream outStream) throws IOException { pStream.println(); } /** * encodeBufferPrefix writes the begin line to the output stream. */ protected void encodeBufferPrefix(OutputStream a) throws IOException { super.pStream = new PrintStream(a); super.pStream.print("begin "+mode+" "); if (bufferName != null) { super.pStream.println(bufferName); } else { super.pStream.println("encoder.bin"); } super.pStream.flush(); } /** * encodeBufferSuffix writes the single line containing space (' ') and * the line containing the word 'end' to the output stream. */ protected void encodeBufferSuffix(OutputStream a) throws IOException { super.pStream.println(" \nend"); super.pStream.flush(); } }