[1050] | 1 | /* gun.c -- simple gunzip to give an example of the use of inflateBack()
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| 2 | * Copyright (C) 2003, 2005, 2008, 2010, 2012 Mark Adler
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| 3 | * For conditions of distribution and use, see copyright notice in zlib.h
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| 4 | Version 1.7 12 August 2012 Mark Adler */
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| 5 |
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| 6 | /* Version history:
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| 7 | 1.0 16 Feb 2003 First version for testing of inflateBack()
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| 8 | 1.1 21 Feb 2005 Decompress concatenated gzip streams
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| 9 | Remove use of "this" variable (C++ keyword)
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| 10 | Fix return value for in()
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| 11 | Improve allocation failure checking
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| 12 | Add typecasting for void * structures
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| 13 | Add -h option for command version and usage
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| 14 | Add a bunch of comments
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| 15 | 1.2 20 Mar 2005 Add Unix compress (LZW) decompression
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| 16 | Copy file attributes from input file to output file
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| 17 | 1.3 12 Jun 2005 Add casts for error messages [Oberhumer]
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| 18 | 1.4 8 Dec 2006 LZW decompression speed improvements
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| 19 | 1.5 9 Feb 2008 Avoid warning in latest version of gcc
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| 20 | 1.6 17 Jan 2010 Avoid signed/unsigned comparison warnings
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| 21 | 1.7 12 Aug 2012 Update for z_const usage in zlib 1.2.8
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| 22 | */
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| 23 |
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| 24 | /*
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| 25 | gun [ -t ] [ name ... ]
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| 26 |
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| 27 | decompresses the data in the named gzip files. If no arguments are given,
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| 28 | gun will decompress from stdin to stdout. The names must end in .gz, -gz,
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| 29 | .z, -z, _z, or .Z. The uncompressed data will be written to a file name
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| 30 | with the suffix stripped. On success, the original file is deleted. On
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| 31 | failure, the output file is deleted. For most failures, the command will
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| 32 | continue to process the remaining names on the command line. A memory
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| 33 | allocation failure will abort the command. If -t is specified, then the
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| 34 | listed files or stdin will be tested as gzip files for integrity (without
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| 35 | checking for a proper suffix), no output will be written, and no files
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| 36 | will be deleted.
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| 37 |
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| 38 | Like gzip, gun allows concatenated gzip streams and will decompress them,
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| 39 | writing all of the uncompressed data to the output. Unlike gzip, gun allows
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| 40 | an empty file on input, and will produce no error writing an empty output
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| 41 | file.
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| 42 |
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| 43 | gun will also decompress files made by Unix compress, which uses LZW
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| 44 | compression. These files are automatically detected by virtue of their
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| 45 | magic header bytes. Since the end of Unix compress stream is marked by the
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| 46 | end-of-file, they cannot be concantenated. If a Unix compress stream is
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| 47 | encountered in an input file, it is the last stream in that file.
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| 48 |
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| 49 | Like gunzip and uncompress, the file attributes of the orignal compressed
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| 50 | file are maintained in the final uncompressed file, to the extent that the
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| 51 | user permissions allow it.
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| 52 |
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| 53 | On my Mac OS X PowerPC G4, gun is almost twice as fast as gunzip (version
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| 54 | 1.2.4) is on the same file, when gun is linked with zlib 1.2.2. Also the
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| 55 | LZW decompression provided by gun is about twice as fast as the standard
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| 56 | Unix uncompress command.
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| 57 | */
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| 58 |
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| 59 | /* external functions and related types and constants */
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| 60 | #include <stdio.h> /* fprintf() */
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| 61 | #include <stdlib.h> /* malloc(), free() */
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| 62 | #include <string.h> /* strerror(), strcmp(), strlen(), memcpy() */
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| 63 | #include <errno.h> /* errno */
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| 64 | #include <fcntl.h> /* open() */
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| 65 | #include <unistd.h> /* read(), write(), close(), chown(), unlink() */
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| 66 | #include <sys/types.h>
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| 67 | #include <sys/stat.h> /* stat(), chmod() */
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| 68 | #include <utime.h> /* utime() */
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| 69 | #include "zlib.h" /* inflateBackInit(), inflateBack(), */
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| 70 | /* inflateBackEnd(), crc32() */
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| 71 |
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| 72 | /* function declaration */
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| 73 | #define local static
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| 74 |
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| 75 | /* buffer constants */
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| 76 | #define SIZE 32768U /* input and output buffer sizes */
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| 77 | #define PIECE 16384 /* limits i/o chunks for 16-bit int case */
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| 78 |
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| 79 | /* structure for infback() to pass to input function in() -- it maintains the
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| 80 | input file and a buffer of size SIZE */
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| 81 | struct ind {
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| 82 | int infile;
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| 83 | unsigned char *inbuf;
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| 84 | };
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| 85 |
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| 86 | /* Load input buffer, assumed to be empty, and return bytes loaded and a
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| 87 | pointer to them. read() is called until the buffer is full, or until it
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| 88 | returns end-of-file or error. Return 0 on error. */
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| 89 | local unsigned in(void *in_desc, z_const unsigned char **buf)
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| 90 | {
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| 91 | int ret;
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| 92 | unsigned len;
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| 93 | unsigned char *next;
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| 94 | struct ind *me = (struct ind *)in_desc;
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| 95 |
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| 96 | next = me->inbuf;
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| 97 | *buf = next;
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| 98 | len = 0;
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| 99 | do {
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| 100 | ret = PIECE;
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| 101 | if ((unsigned)ret > SIZE - len)
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| 102 | ret = (int)(SIZE - len);
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| 103 | ret = (int)read(me->infile, next, ret);
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| 104 | if (ret == -1) {
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| 105 | len = 0;
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| 106 | break;
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| 107 | }
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| 108 | next += ret;
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| 109 | len += ret;
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| 110 | } while (ret != 0 && len < SIZE);
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| 111 | return len;
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| 112 | }
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| 113 |
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| 114 | /* structure for infback() to pass to output function out() -- it maintains the
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| 115 | output file, a running CRC-32 check on the output and the total number of
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| 116 | bytes output, both for checking against the gzip trailer. (The length in
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| 117 | the gzip trailer is stored modulo 2^32, so it's ok if a long is 32 bits and
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| 118 | the output is greater than 4 GB.) */
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| 119 | struct outd {
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| 120 | int outfile;
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| 121 | int check; /* true if checking crc and total */
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| 122 | unsigned long crc;
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| 123 | unsigned long total;
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| 124 | };
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| 125 |
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| 126 | /* Write output buffer and update the CRC-32 and total bytes written. write()
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| 127 | is called until all of the output is written or an error is encountered.
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| 128 | On success out() returns 0. For a write failure, out() returns 1. If the
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| 129 | output file descriptor is -1, then nothing is written.
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| 130 | */
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| 131 | local int out(void *out_desc, unsigned char *buf, unsigned len)
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| 132 | {
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| 133 | int ret;
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| 134 | struct outd *me = (struct outd *)out_desc;
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| 135 |
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| 136 | if (me->check) {
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| 137 | me->crc = crc32(me->crc, buf, len);
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| 138 | me->total += len;
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| 139 | }
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| 140 | if (me->outfile != -1)
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| 141 | do {
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| 142 | ret = PIECE;
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| 143 | if ((unsigned)ret > len)
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| 144 | ret = (int)len;
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| 145 | ret = (int)write(me->outfile, buf, ret);
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| 146 | if (ret == -1)
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| 147 | return 1;
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| 148 | buf += ret;
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| 149 | len -= ret;
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| 150 | } while (len != 0);
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| 151 | return 0;
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| 152 | }
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| 153 |
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| 154 | /* next input byte macro for use inside lunpipe() and gunpipe() */
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| 155 | #define NEXT() (have ? 0 : (have = in(indp, &next)), \
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| 156 | last = have ? (have--, (int)(*next++)) : -1)
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| 157 |
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| 158 | /* memory for gunpipe() and lunpipe() --
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| 159 | the first 256 entries of prefix[] and suffix[] are never used, could
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| 160 | have offset the index, but it's faster to waste the memory */
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| 161 | unsigned char inbuf[SIZE]; /* input buffer */
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| 162 | unsigned char outbuf[SIZE]; /* output buffer */
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| 163 | unsigned short prefix[65536]; /* index to LZW prefix string */
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| 164 | unsigned char suffix[65536]; /* one-character LZW suffix */
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| 165 | unsigned char match[65280 + 2]; /* buffer for reversed match or gzip
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| 166 | 32K sliding window */
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| 167 |
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| 168 | /* throw out what's left in the current bits byte buffer (this is a vestigial
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| 169 | aspect of the compressed data format derived from an implementation that
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| 170 | made use of a special VAX machine instruction!) */
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| 171 | #define FLUSHCODE() \
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| 172 | do { \
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| 173 | left = 0; \
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| 174 | rem = 0; \
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| 175 | if (chunk > have) { \
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| 176 | chunk -= have; \
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| 177 | have = 0; \
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| 178 | if (NEXT() == -1) \
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| 179 | break; \
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| 180 | chunk--; \
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| 181 | if (chunk > have) { \
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| 182 | chunk = have = 0; \
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| 183 | break; \
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| 184 | } \
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| 185 | } \
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| 186 | have -= chunk; \
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| 187 | next += chunk; \
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| 188 | chunk = 0; \
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| 189 | } while (0)
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| 190 |
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| 191 | /* Decompress a compress (LZW) file from indp to outfile. The compress magic
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| 192 | header (two bytes) has already been read and verified. There are have bytes
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| 193 | of buffered input at next. strm is used for passing error information back
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| 194 | to gunpipe().
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| 195 |
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| 196 | lunpipe() will return Z_OK on success, Z_BUF_ERROR for an unexpected end of
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| 197 | file, read error, or write error (a write error indicated by strm->next_in
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| 198 | not equal to Z_NULL), or Z_DATA_ERROR for invalid input.
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| 199 | */
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| 200 | local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp,
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| 201 | int outfile, z_stream *strm)
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| 202 | {
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| 203 | int last; /* last byte read by NEXT(), or -1 if EOF */
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| 204 | unsigned chunk; /* bytes left in current chunk */
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| 205 | int left; /* bits left in rem */
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| 206 | unsigned rem; /* unused bits from input */
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| 207 | int bits; /* current bits per code */
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| 208 | unsigned code; /* code, table traversal index */
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| 209 | unsigned mask; /* mask for current bits codes */
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| 210 | int max; /* maximum bits per code for this stream */
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| 211 | unsigned flags; /* compress flags, then block compress flag */
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| 212 | unsigned end; /* last valid entry in prefix/suffix tables */
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| 213 | unsigned temp; /* current code */
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| 214 | unsigned prev; /* previous code */
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| 215 | unsigned final; /* last character written for previous code */
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| 216 | unsigned stack; /* next position for reversed string */
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| 217 | unsigned outcnt; /* bytes in output buffer */
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| 218 | struct outd outd; /* output structure */
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| 219 | unsigned char *p;
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| 220 |
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| 221 | /* set up output */
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| 222 | outd.outfile = outfile;
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| 223 | outd.check = 0;
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| 224 |
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| 225 | /* process remainder of compress header -- a flags byte */
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| 226 | flags = NEXT();
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| 227 | if (last == -1)
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| 228 | return Z_BUF_ERROR;
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| 229 | if (flags & 0x60) {
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| 230 | strm->msg = (char *)"unknown lzw flags set";
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| 231 | return Z_DATA_ERROR;
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| 232 | }
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| 233 | max = flags & 0x1f;
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| 234 | if (max < 9 || max > 16) {
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| 235 | strm->msg = (char *)"lzw bits out of range";
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| 236 | return Z_DATA_ERROR;
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| 237 | }
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| 238 | if (max == 9) /* 9 doesn't really mean 9 */
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| 239 | max = 10;
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| 240 | flags &= 0x80; /* true if block compress */
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| 241 |
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| 242 | /* clear table */
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| 243 | bits = 9;
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| 244 | mask = 0x1ff;
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| 245 | end = flags ? 256 : 255;
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| 246 |
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| 247 | /* set up: get first 9-bit code, which is the first decompressed byte, but
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| 248 | don't create a table entry until the next code */
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| 249 | if (NEXT() == -1) /* no compressed data is ok */
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| 250 | return Z_OK;
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| 251 | final = prev = (unsigned)last; /* low 8 bits of code */
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| 252 | if (NEXT() == -1) /* missing a bit */
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| 253 | return Z_BUF_ERROR;
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| 254 | if (last & 1) { /* code must be < 256 */
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| 255 | strm->msg = (char *)"invalid lzw code";
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| 256 | return Z_DATA_ERROR;
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| 257 | }
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| 258 | rem = (unsigned)last >> 1; /* remaining 7 bits */
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| 259 | left = 7;
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| 260 | chunk = bits - 2; /* 7 bytes left in this chunk */
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| 261 | outbuf[0] = (unsigned char)final; /* write first decompressed byte */
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| 262 | outcnt = 1;
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| 263 |
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| 264 | /* decode codes */
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| 265 | stack = 0;
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| 266 | for (;;) {
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| 267 | /* if the table will be full after this, increment the code size */
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| 268 | if (end >= mask && bits < max) {
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| 269 | FLUSHCODE();
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| 270 | bits++;
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| 271 | mask <<= 1;
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| 272 | mask++;
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| 273 | }
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| 274 |
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| 275 | /* get a code of length bits */
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| 276 | if (chunk == 0) /* decrement chunk modulo bits */
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| 277 | chunk = bits;
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| 278 | code = rem; /* low bits of code */
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| 279 | if (NEXT() == -1) { /* EOF is end of compressed data */
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| 280 | /* write remaining buffered output */
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| 281 | if (outcnt && out(&outd, outbuf, outcnt)) {
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| 282 | strm->next_in = outbuf; /* signal write error */
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| 283 | return Z_BUF_ERROR;
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| 284 | }
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| 285 | return Z_OK;
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| 286 | }
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| 287 | code += (unsigned)last << left; /* middle (or high) bits of code */
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| 288 | left += 8;
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| 289 | chunk--;
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| 290 | if (bits > left) { /* need more bits */
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| 291 | if (NEXT() == -1) /* can't end in middle of code */
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| 292 | return Z_BUF_ERROR;
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| 293 | code += (unsigned)last << left; /* high bits of code */
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| 294 | left += 8;
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| 295 | chunk--;
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| 296 | }
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| 297 | code &= mask; /* mask to current code length */
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| 298 | left -= bits; /* number of unused bits */
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| 299 | rem = (unsigned)last >> (8 - left); /* unused bits from last byte */
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| 300 |
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| 301 | /* process clear code (256) */
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| 302 | if (code == 256 && flags) {
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| 303 | FLUSHCODE();
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| 304 | bits = 9; /* initialize bits and mask */
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| 305 | mask = 0x1ff;
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| 306 | end = 255; /* empty table */
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| 307 | continue; /* get next code */
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| 308 | }
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| 309 |
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| 310 | /* special code to reuse last match */
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| 311 | temp = code; /* save the current code */
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| 312 | if (code > end) {
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| 313 | /* Be picky on the allowed code here, and make sure that the code
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| 314 | we drop through (prev) will be a valid index so that random
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| 315 | input does not cause an exception. The code != end + 1 check is
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| 316 | empirically derived, and not checked in the original uncompress
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| 317 | code. If this ever causes a problem, that check could be safely
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| 318 | removed. Leaving this check in greatly improves gun's ability
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| 319 | to detect random or corrupted input after a compress header.
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| 320 | In any case, the prev > end check must be retained. */
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| 321 | if (code != end + 1 || prev > end) {
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| 322 | strm->msg = (char *)"invalid lzw code";
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| 323 | return Z_DATA_ERROR;
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| 324 | }
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| 325 | match[stack++] = (unsigned char)final;
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| 326 | code = prev;
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| 327 | }
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| 328 |
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| 329 | /* walk through linked list to generate output in reverse order */
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| 330 | p = match + stack;
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| 331 | while (code >= 256) {
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| 332 | *p++ = suffix[code];
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| 333 | code = prefix[code];
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| 334 | }
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| 335 | stack = p - match;
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| 336 | match[stack++] = (unsigned char)code;
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| 337 | final = code;
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| 338 |
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| 339 | /* link new table entry */
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| 340 | if (end < mask) {
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| 341 | end++;
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| 342 | prefix[end] = (unsigned short)prev;
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| 343 | suffix[end] = (unsigned char)final;
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| 344 | }
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| 345 |
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| 346 | /* set previous code for next iteration */
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| 347 | prev = temp;
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| 348 |
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| 349 | /* write output in forward order */
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| 350 | while (stack > SIZE - outcnt) {
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| 351 | while (outcnt < SIZE)
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| 352 | outbuf[outcnt++] = match[--stack];
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| 353 | if (out(&outd, outbuf, outcnt)) {
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| 354 | strm->next_in = outbuf; /* signal write error */
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| 355 | return Z_BUF_ERROR;
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| 356 | }
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| 357 | outcnt = 0;
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| 358 | }
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| 359 | p = match + stack;
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| 360 | do {
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| 361 | outbuf[outcnt++] = *--p;
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| 362 | } while (p > match);
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| 363 | stack = 0;
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| 364 |
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| 365 | /* loop for next code with final and prev as the last match, rem and
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| 366 | left provide the first 0..7 bits of the next code, end is the last
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| 367 | valid table entry */
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| 368 | }
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| 369 | }
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| 370 |
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| 371 | /* Decompress a gzip file from infile to outfile. strm is assumed to have been
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| 372 | successfully initialized with inflateBackInit(). The input file may consist
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| 373 | of a series of gzip streams, in which case all of them will be decompressed
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| 374 | to the output file. If outfile is -1, then the gzip stream(s) integrity is
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| 375 | checked and nothing is written.
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| 376 |
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| 377 | The return value is a zlib error code: Z_MEM_ERROR if out of memory,
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| 378 | Z_DATA_ERROR if the header or the compressed data is invalid, or if the
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| 379 | trailer CRC-32 check or length doesn't match, Z_BUF_ERROR if the input ends
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| 380 | prematurely or a write error occurs, or Z_ERRNO if junk (not a another gzip
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| 381 | stream) follows a valid gzip stream.
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| 382 | */
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| 383 | local int gunpipe(z_stream *strm, int infile, int outfile)
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| 384 | {
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| 385 | int ret, first, last;
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| 386 | unsigned have, flags, len;
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| 387 | z_const unsigned char *next = NULL;
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| 388 | struct ind ind, *indp;
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| 389 | struct outd outd;
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| 390 |
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| 391 | /* setup input buffer */
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| 392 | ind.infile = infile;
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| 393 | ind.inbuf = inbuf;
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| 394 | indp = &ind;
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| 395 |
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| 396 | /* decompress concatenated gzip streams */
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| 397 | have = 0; /* no input data read in yet */
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| 398 | first = 1; /* looking for first gzip header */
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| 399 | strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */
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| 400 | for (;;) {
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| 401 | /* look for the two magic header bytes for a gzip stream */
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| 402 | if (NEXT() == -1) {
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| 403 | ret = Z_OK;
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| 404 | break; /* empty gzip stream is ok */
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| 405 | }
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| 406 | if (last != 31 || (NEXT() != 139 && last != 157)) {
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| 407 | strm->msg = (char *)"incorrect header check";
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| 408 | ret = first ? Z_DATA_ERROR : Z_ERRNO;
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| 409 | break; /* not a gzip or compress header */
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| 410 | }
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| 411 | first = 0; /* next non-header is junk */
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| 412 |
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| 413 | /* process a compress (LZW) file -- can't be concatenated after this */
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| 414 | if (last == 157) {
|
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| 415 | ret = lunpipe(have, next, indp, outfile, strm);
|
---|
| 416 | break;
|
---|
| 417 | }
|
---|
| 418 |
|
---|
| 419 | /* process remainder of gzip header */
|
---|
| 420 | ret = Z_BUF_ERROR;
|
---|
| 421 | if (NEXT() != 8) { /* only deflate method allowed */
|
---|
| 422 | if (last == -1) break;
|
---|
| 423 | strm->msg = (char *)"unknown compression method";
|
---|
| 424 | ret = Z_DATA_ERROR;
|
---|
| 425 | break;
|
---|
| 426 | }
|
---|
| 427 | flags = NEXT(); /* header flags */
|
---|
| 428 | NEXT(); /* discard mod time, xflgs, os */
|
---|
| 429 | NEXT();
|
---|
| 430 | NEXT();
|
---|
| 431 | NEXT();
|
---|
| 432 | NEXT();
|
---|
| 433 | NEXT();
|
---|
| 434 | if (last == -1) break;
|
---|
| 435 | if (flags & 0xe0) {
|
---|
| 436 | strm->msg = (char *)"unknown header flags set";
|
---|
| 437 | ret = Z_DATA_ERROR;
|
---|
| 438 | break;
|
---|
| 439 | }
|
---|
| 440 | if (flags & 4) { /* extra field */
|
---|
| 441 | len = NEXT();
|
---|
| 442 | len += (unsigned)(NEXT()) << 8;
|
---|
| 443 | if (last == -1) break;
|
---|
| 444 | while (len > have) {
|
---|
| 445 | len -= have;
|
---|
| 446 | have = 0;
|
---|
| 447 | if (NEXT() == -1) break;
|
---|
| 448 | len--;
|
---|
| 449 | }
|
---|
| 450 | if (last == -1) break;
|
---|
| 451 | have -= len;
|
---|
| 452 | next += len;
|
---|
| 453 | }
|
---|
| 454 | if (flags & 8) /* file name */
|
---|
| 455 | while (NEXT() != 0 && last != -1)
|
---|
| 456 | ;
|
---|
| 457 | if (flags & 16) /* comment */
|
---|
| 458 | while (NEXT() != 0 && last != -1)
|
---|
| 459 | ;
|
---|
| 460 | if (flags & 2) { /* header crc */
|
---|
| 461 | NEXT();
|
---|
| 462 | NEXT();
|
---|
| 463 | }
|
---|
| 464 | if (last == -1) break;
|
---|
| 465 |
|
---|
| 466 | /* set up output */
|
---|
| 467 | outd.outfile = outfile;
|
---|
| 468 | outd.check = 1;
|
---|
| 469 | outd.crc = crc32(0L, Z_NULL, 0);
|
---|
| 470 | outd.total = 0;
|
---|
| 471 |
|
---|
| 472 | /* decompress data to output */
|
---|
| 473 | strm->next_in = next;
|
---|
| 474 | strm->avail_in = have;
|
---|
| 475 | ret = inflateBack(strm, in, indp, out, &outd);
|
---|
| 476 | if (ret != Z_STREAM_END) break;
|
---|
| 477 | next = strm->next_in;
|
---|
| 478 | have = strm->avail_in;
|
---|
| 479 | strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */
|
---|
| 480 |
|
---|
| 481 | /* check trailer */
|
---|
| 482 | ret = Z_BUF_ERROR;
|
---|
| 483 | if (NEXT() != (int)(outd.crc & 0xff) ||
|
---|
| 484 | NEXT() != (int)((outd.crc >> 8) & 0xff) ||
|
---|
| 485 | NEXT() != (int)((outd.crc >> 16) & 0xff) ||
|
---|
| 486 | NEXT() != (int)((outd.crc >> 24) & 0xff)) {
|
---|
| 487 | /* crc error */
|
---|
| 488 | if (last != -1) {
|
---|
| 489 | strm->msg = (char *)"incorrect data check";
|
---|
| 490 | ret = Z_DATA_ERROR;
|
---|
| 491 | }
|
---|
| 492 | break;
|
---|
| 493 | }
|
---|
| 494 | if (NEXT() != (int)(outd.total & 0xff) ||
|
---|
| 495 | NEXT() != (int)((outd.total >> 8) & 0xff) ||
|
---|
| 496 | NEXT() != (int)((outd.total >> 16) & 0xff) ||
|
---|
| 497 | NEXT() != (int)((outd.total >> 24) & 0xff)) {
|
---|
| 498 | /* length error */
|
---|
| 499 | if (last != -1) {
|
---|
| 500 | strm->msg = (char *)"incorrect length check";
|
---|
| 501 | ret = Z_DATA_ERROR;
|
---|
| 502 | }
|
---|
| 503 | break;
|
---|
| 504 | }
|
---|
| 505 |
|
---|
| 506 | /* go back and look for another gzip stream */
|
---|
| 507 | }
|
---|
| 508 |
|
---|
| 509 | /* clean up and return */
|
---|
| 510 | return ret;
|
---|
| 511 | }
|
---|
| 512 |
|
---|
| 513 | /* Copy file attributes, from -> to, as best we can. This is best effort, so
|
---|
| 514 | no errors are reported. The mode bits, including suid, sgid, and the sticky
|
---|
| 515 | bit are copied (if allowed), the owner's user id and group id are copied
|
---|
| 516 | (again if allowed), and the access and modify times are copied. */
|
---|
| 517 | local void copymeta(char *from, char *to)
|
---|
| 518 | {
|
---|
| 519 | struct stat was;
|
---|
| 520 | struct utimbuf when;
|
---|
| 521 |
|
---|
| 522 | /* get all of from's Unix meta data, return if not a regular file */
|
---|
| 523 | if (stat(from, &was) != 0 || (was.st_mode & S_IFMT) != S_IFREG)
|
---|
| 524 | return;
|
---|
| 525 |
|
---|
| 526 | /* set to's mode bits, ignore errors */
|
---|
| 527 | (void)chmod(to, was.st_mode & 07777);
|
---|
| 528 |
|
---|
| 529 | /* copy owner's user and group, ignore errors */
|
---|
| 530 | (void)chown(to, was.st_uid, was.st_gid);
|
---|
| 531 |
|
---|
| 532 | /* copy access and modify times, ignore errors */
|
---|
| 533 | when.actime = was.st_atime;
|
---|
| 534 | when.modtime = was.st_mtime;
|
---|
| 535 | (void)utime(to, &when);
|
---|
| 536 | }
|
---|
| 537 |
|
---|
| 538 | /* Decompress the file inname to the file outnname, of if test is true, just
|
---|
| 539 | decompress without writing and check the gzip trailer for integrity. If
|
---|
| 540 | inname is NULL or an empty string, read from stdin. If outname is NULL or
|
---|
| 541 | an empty string, write to stdout. strm is a pre-initialized inflateBack
|
---|
| 542 | structure. When appropriate, copy the file attributes from inname to
|
---|
| 543 | outname.
|
---|
| 544 |
|
---|
| 545 | gunzip() returns 1 if there is an out-of-memory error or an unexpected
|
---|
| 546 | return code from gunpipe(). Otherwise it returns 0.
|
---|
| 547 | */
|
---|
| 548 | local int gunzip(z_stream *strm, char *inname, char *outname, int test)
|
---|
| 549 | {
|
---|
| 550 | int ret;
|
---|
| 551 | int infile, outfile;
|
---|
| 552 |
|
---|
| 553 | /* open files */
|
---|
| 554 | if (inname == NULL || *inname == 0) {
|
---|
| 555 | inname = "-";
|
---|
| 556 | infile = 0; /* stdin */
|
---|
| 557 | }
|
---|
| 558 | else {
|
---|
| 559 | infile = open(inname, O_RDONLY, 0);
|
---|
| 560 | if (infile == -1) {
|
---|
| 561 | fprintf(stderr, "gun cannot open %s\n", inname);
|
---|
| 562 | return 0;
|
---|
| 563 | }
|
---|
| 564 | }
|
---|
| 565 | if (test)
|
---|
| 566 | outfile = -1;
|
---|
| 567 | else if (outname == NULL || *outname == 0) {
|
---|
| 568 | outname = "-";
|
---|
| 569 | outfile = 1; /* stdout */
|
---|
| 570 | }
|
---|
| 571 | else {
|
---|
| 572 | outfile = open(outname, O_CREAT | O_TRUNC | O_WRONLY, 0666);
|
---|
| 573 | if (outfile == -1) {
|
---|
| 574 | close(infile);
|
---|
| 575 | fprintf(stderr, "gun cannot create %s\n", outname);
|
---|
| 576 | return 0;
|
---|
| 577 | }
|
---|
| 578 | }
|
---|
| 579 | errno = 0;
|
---|
| 580 |
|
---|
| 581 | /* decompress */
|
---|
| 582 | ret = gunpipe(strm, infile, outfile);
|
---|
| 583 | if (outfile > 2) close(outfile);
|
---|
| 584 | if (infile > 2) close(infile);
|
---|
| 585 |
|
---|
| 586 | /* interpret result */
|
---|
| 587 | switch (ret) {
|
---|
| 588 | case Z_OK:
|
---|
| 589 | case Z_ERRNO:
|
---|
| 590 | if (infile > 2 && outfile > 2) {
|
---|
| 591 | copymeta(inname, outname); /* copy attributes */
|
---|
| 592 | unlink(inname);
|
---|
| 593 | }
|
---|
| 594 | if (ret == Z_ERRNO)
|
---|
| 595 | fprintf(stderr, "gun warning: trailing garbage ignored in %s\n",
|
---|
| 596 | inname);
|
---|
| 597 | break;
|
---|
| 598 | case Z_DATA_ERROR:
|
---|
| 599 | if (outfile > 2) unlink(outname);
|
---|
| 600 | fprintf(stderr, "gun data error on %s: %s\n", inname, strm->msg);
|
---|
| 601 | break;
|
---|
| 602 | case Z_MEM_ERROR:
|
---|
| 603 | if (outfile > 2) unlink(outname);
|
---|
| 604 | fprintf(stderr, "gun out of memory error--aborting\n");
|
---|
| 605 | return 1;
|
---|
| 606 | case Z_BUF_ERROR:
|
---|
| 607 | if (outfile > 2) unlink(outname);
|
---|
| 608 | if (strm->next_in != Z_NULL) {
|
---|
| 609 | fprintf(stderr, "gun write error on %s: %s\n",
|
---|
| 610 | outname, strerror(errno));
|
---|
| 611 | }
|
---|
| 612 | else if (errno) {
|
---|
| 613 | fprintf(stderr, "gun read error on %s: %s\n",
|
---|
| 614 | inname, strerror(errno));
|
---|
| 615 | }
|
---|
| 616 | else {
|
---|
| 617 | fprintf(stderr, "gun unexpected end of file on %s\n",
|
---|
| 618 | inname);
|
---|
| 619 | }
|
---|
| 620 | break;
|
---|
| 621 | default:
|
---|
| 622 | if (outfile > 2) unlink(outname);
|
---|
| 623 | fprintf(stderr, "gun internal error--aborting\n");
|
---|
| 624 | return 1;
|
---|
| 625 | }
|
---|
| 626 | return 0;
|
---|
| 627 | }
|
---|
| 628 |
|
---|
| 629 | /* Process the gun command line arguments. See the command syntax near the
|
---|
| 630 | beginning of this source file. */
|
---|
| 631 | int main(int argc, char **argv)
|
---|
| 632 | {
|
---|
| 633 | int ret, len, test;
|
---|
| 634 | char *outname;
|
---|
| 635 | unsigned char *window;
|
---|
| 636 | z_stream strm;
|
---|
| 637 |
|
---|
| 638 | /* initialize inflateBack state for repeated use */
|
---|
| 639 | window = match; /* reuse LZW match buffer */
|
---|
| 640 | strm.zalloc = Z_NULL;
|
---|
| 641 | strm.zfree = Z_NULL;
|
---|
| 642 | strm.opaque = Z_NULL;
|
---|
| 643 | ret = inflateBackInit(&strm, 15, window);
|
---|
| 644 | if (ret != Z_OK) {
|
---|
| 645 | fprintf(stderr, "gun out of memory error--aborting\n");
|
---|
| 646 | return 1;
|
---|
| 647 | }
|
---|
| 648 |
|
---|
| 649 | /* decompress each file to the same name with the suffix removed */
|
---|
| 650 | argc--;
|
---|
| 651 | argv++;
|
---|
| 652 | test = 0;
|
---|
| 653 | if (argc && strcmp(*argv, "-h") == 0) {
|
---|
| 654 | fprintf(stderr, "gun 1.6 (17 Jan 2010)\n");
|
---|
| 655 | fprintf(stderr, "Copyright (C) 2003-2010 Mark Adler\n");
|
---|
| 656 | fprintf(stderr, "usage: gun [-t] [file1.gz [file2.Z ...]]\n");
|
---|
| 657 | return 0;
|
---|
| 658 | }
|
---|
| 659 | if (argc && strcmp(*argv, "-t") == 0) {
|
---|
| 660 | test = 1;
|
---|
| 661 | argc--;
|
---|
| 662 | argv++;
|
---|
| 663 | }
|
---|
| 664 | if (argc)
|
---|
| 665 | do {
|
---|
| 666 | if (test)
|
---|
| 667 | outname = NULL;
|
---|
| 668 | else {
|
---|
| 669 | len = (int)strlen(*argv);
|
---|
| 670 | if (strcmp(*argv + len - 3, ".gz") == 0 ||
|
---|
| 671 | strcmp(*argv + len - 3, "-gz") == 0)
|
---|
| 672 | len -= 3;
|
---|
| 673 | else if (strcmp(*argv + len - 2, ".z") == 0 ||
|
---|
| 674 | strcmp(*argv + len - 2, "-z") == 0 ||
|
---|
| 675 | strcmp(*argv + len - 2, "_z") == 0 ||
|
---|
| 676 | strcmp(*argv + len - 2, ".Z") == 0)
|
---|
| 677 | len -= 2;
|
---|
| 678 | else {
|
---|
| 679 | fprintf(stderr, "gun error: no gz type on %s--skipping\n",
|
---|
| 680 | *argv);
|
---|
| 681 | continue;
|
---|
| 682 | }
|
---|
| 683 | outname = malloc(len + 1);
|
---|
| 684 | if (outname == NULL) {
|
---|
| 685 | fprintf(stderr, "gun out of memory error--aborting\n");
|
---|
| 686 | ret = 1;
|
---|
| 687 | break;
|
---|
| 688 | }
|
---|
| 689 | memcpy(outname, *argv, len);
|
---|
| 690 | outname[len] = 0;
|
---|
| 691 | }
|
---|
| 692 | ret = gunzip(&strm, *argv, outname, test);
|
---|
| 693 | if (outname != NULL) free(outname);
|
---|
| 694 | if (ret) break;
|
---|
| 695 | } while (argv++, --argc);
|
---|
| 696 | else
|
---|
| 697 | ret = gunzip(&strm, NULL, NULL, test);
|
---|
| 698 |
|
---|
| 699 | /* clean up */
|
---|
| 700 | inflateBackEnd(&strm);
|
---|
| 701 | return ret;
|
---|
| 702 | }
|
---|