| /* |
| * Copyright (c) 1995, 2001, 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.PushbackInputStream; |
| import java.io.OutputStream; |
| import java.io.PrintStream; |
| import java.io.IOException; |
| |
| /** |
| * This class implements a Berkeley uu character decoder. This decoder |
| * was made famous by the uudecode 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 buffer 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]' |
| * |
| * If an error is encountered during decoding this class throws a |
| * CEFormatException. The specific detail messages are: |
| * |
| * <pre> |
| * "UUDecoder: No begin line." |
| * "UUDecoder: Malformed begin line." |
| * "UUDecoder: Short Buffer." |
| * "UUDecoder: Bad Line Length." |
| * "UUDecoder: Missing 'end' line." |
| * </pre> |
| * |
| * @author Chuck McManis |
| * @see CharacterDecoder |
| * @see UUEncoder |
| */ |
| public class UUDecoder extends CharacterDecoder { |
| |
| /** |
| * This string contains the name that was in the buffer being decoded. |
| */ |
| public 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: |
| * <pre> |
| * (owner) (group) (others) |
| * rwx rwx rwx (r = read, w = write, x = execute) |
| *</pre> |
| * |
| */ |
| public int mode; |
| |
| |
| /** |
| * UU encoding specifies 3 bytes per atom. |
| */ |
| protected int bytesPerAtom() { |
| return (3); |
| } |
| |
| /** |
| * All UU lines have 45 bytes on them, for line length of 15*4+1 or 61 |
| * characters per line. |
| */ |
| protected int bytesPerLine() { |
| return (45); |
| } |
| |
| /** This is used to decode the atoms */ |
| private byte decoderBuffer[] = new byte[4]; |
| |
| /** |
| * Decode a UU atom. Note that if l is less than 3 we don't write |
| * the extra bits, however the encoder always encodes 4 character |
| * groups even when they are not needed. |
| */ |
| protected void decodeAtom(PushbackInputStream inStream, OutputStream outStream, int l) |
| throws IOException { |
| int i, c1, c2, c3, c4; |
| int a, b, c; |
| StringBuffer x = new StringBuffer(); |
| |
| for (i = 0; i < 4; i++) { |
| c1 = inStream.read(); |
| if (c1 == -1) { |
| throw new CEStreamExhausted(); |
| } |
| x.append((char)c1); |
| decoderBuffer[i] = (byte) ((c1 - ' ') & 0x3f); |
| } |
| a = ((decoderBuffer[0] << 2) & 0xfc) | ((decoderBuffer[1] >>> 4) & 3); |
| b = ((decoderBuffer[1] << 4) & 0xf0) | ((decoderBuffer[2] >>> 2) & 0xf); |
| c = ((decoderBuffer[2] << 6) & 0xc0) | (decoderBuffer[3] & 0x3f); |
| outStream.write((byte)(a & 0xff)); |
| if (l > 1) { |
| outStream.write((byte)( b & 0xff)); |
| } |
| if (l > 2) { |
| outStream.write((byte)(c&0xff)); |
| } |
| } |
| |
| /** |
| * For uuencoded buffers, the data begins with a line of the form: |
| * begin MODE FILENAME |
| * This line always starts in column 1. |
| */ |
| protected void decodeBufferPrefix(PushbackInputStream inStream, OutputStream outStream) throws IOException { |
| int c; |
| StringBuffer q = new StringBuffer(32); |
| String r; |
| boolean sawNewLine; |
| |
| /* |
| * This works by ripping through the buffer until it finds a 'begin' |
| * line or the end of the buffer. |
| */ |
| sawNewLine = true; |
| while (true) { |
| c = inStream.read(); |
| if (c == -1) { |
| throw new CEFormatException("UUDecoder: No begin line."); |
| } |
| if ((c == 'b') && sawNewLine){ |
| c = inStream.read(); |
| if (c == 'e') { |
| break; |
| } |
| } |
| sawNewLine = (c == '\n') || (c == '\r'); |
| } |
| |
| /* |
| * Now we think its begin, (we've seen ^be) so verify it here. |
| */ |
| while ((c != '\n') && (c != '\r')) { |
| c = inStream.read(); |
| if (c == -1) { |
| throw new CEFormatException("UUDecoder: No begin line."); |
| } |
| if ((c != '\n') && (c != '\r')) { |
| q.append((char)c); |
| } |
| } |
| r = q.toString(); |
| if (r.indexOf(' ') != 3) { |
| throw new CEFormatException("UUDecoder: Malformed begin line."); |
| } |
| mode = Integer.parseInt(r.substring(4,7)); |
| bufferName = r.substring(r.indexOf(' ',6)+1); |
| /* |
| * Check for \n after \r |
| */ |
| if (c == '\r') { |
| c = inStream.read (); |
| if ((c != '\n') && (c != -1)) |
| inStream.unread (c); |
| } |
| } |
| |
| /** |
| * In uuencoded buffers, encoded lines start with a character that |
| * represents the number of bytes encoded in this line. The last |
| * line of input is always a line that starts with a single space |
| * character, which would be a zero length line. |
| */ |
| protected int decodeLinePrefix(PushbackInputStream inStream, OutputStream outStream) throws IOException { |
| int c; |
| |
| c = inStream.read(); |
| if (c == ' ') { |
| c = inStream.read(); /* discard the (first)trailing CR or LF */ |
| c = inStream.read(); /* check for a second one */ |
| if ((c != '\n') && (c != -1)) |
| inStream.unread (c); |
| throw new CEStreamExhausted(); |
| } else if (c == -1) { |
| throw new CEFormatException("UUDecoder: Short Buffer."); |
| } |
| |
| c = (c - ' ') & 0x3f; |
| if (c > bytesPerLine()) { |
| throw new CEFormatException("UUDecoder: Bad Line Length."); |
| } |
| return (c); |
| } |
| |
| |
| /** |
| * Find the end of the line for the next operation. |
| * The following sequences are recognized as end-of-line |
| * CR, CR LF, or LF |
| */ |
| protected void decodeLineSuffix(PushbackInputStream inStream, OutputStream outStream) throws IOException { |
| int c; |
| while (true) { |
| c = inStream.read(); |
| if (c == -1) { |
| throw new CEStreamExhausted(); |
| } |
| if (c == '\n') { |
| break; |
| } |
| if (c == '\r') { |
| c = inStream.read(); |
| if ((c != '\n') && (c != -1)) { |
| inStream.unread (c); |
| } |
| break; |
| } |
| } |
| } |
| |
| /** |
| * UUencoded files have a buffer suffix which consists of the word |
| * end. This line should immediately follow the line with a single |
| * space in it. |
| */ |
| protected void decodeBufferSuffix(PushbackInputStream inStream, OutputStream outStream) throws IOException { |
| int c; |
| |
| c = inStream.read(decoderBuffer); |
| if ((decoderBuffer[0] != 'e') || (decoderBuffer[1] != 'n') || |
| (decoderBuffer[2] != 'd')) { |
| throw new CEFormatException("UUDecoder: Missing 'end' line."); |
| } |
| } |
| |
| } |
