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	/*
	* 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:
	* <pre>
	* begin [mode] [filename]
	* </pre>
	*
	* This is followed by one or more lines of the form:
	* <pre>
	* (len)(data)(data)(data) ...
	* </pre>
	* 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:
	* <pre>
	* begin 644 encoder.buf
	* </pre>
	*/
	public UUEncoder() {
	bufferName = "encoder.buf";
	mode = 644;
	}

	/**
	* Specifies a name for the encoded buffer, begin line will be:
	* <pre>
	* begin 644 [FNAME]
	* </pre>
	*/
	public UUEncoder(String fname) {
	bufferName = fname;
	mode = 644;
	}

	/**
	* Specifies a name and mode for the encoded buffer, begin line will be:
	* <pre>
	* begin [MODE] [FNAME]
	* </pre>
	*/
	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();
	}

	}

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