|  | /* gun.c -- simple gunzip to give an example of the use of inflateBack() | 
|  | * Copyright (C) 2003, 2005, 2008, 2010, 2012 Mark Adler | 
|  | * For conditions of distribution and use, see copyright notice in zlib.h | 
|  | Version 1.7  12 August 2012  Mark Adler */ | 
|  |  | 
|  | /* Version history: | 
|  | 1.0  16 Feb 2003  First version for testing of inflateBack() | 
|  | 1.1  21 Feb 2005  Decompress concatenated gzip streams | 
|  | Remove use of "this" variable (C++ keyword) | 
|  | Fix return value for in() | 
|  | Improve allocation failure checking | 
|  | Add typecasting for void * structures | 
|  | Add -h option for command version and usage | 
|  | Add a bunch of comments | 
|  | 1.2  20 Mar 2005  Add Unix compress (LZW) decompression | 
|  | Copy file attributes from input file to output file | 
|  | 1.3  12 Jun 2005  Add casts for error messages [Oberhumer] | 
|  | 1.4   8 Dec 2006  LZW decompression speed improvements | 
|  | 1.5   9 Feb 2008  Avoid warning in latest version of gcc | 
|  | 1.6  17 Jan 2010  Avoid signed/unsigned comparison warnings | 
|  | 1.7  12 Aug 2012  Update for z_const usage in zlib 1.2.8 | 
|  | */ | 
|  |  | 
|  | /* | 
|  | gun [ -t ] [ name ... ] | 
|  |  | 
|  | decompresses the data in the named gzip files.  If no arguments are given, | 
|  | gun will decompress from stdin to stdout.  The names must end in .gz, -gz, | 
|  | .z, -z, _z, or .Z.  The uncompressed data will be written to a file name | 
|  | with the suffix stripped.  On success, the original file is deleted.  On | 
|  | failure, the output file is deleted.  For most failures, the command will | 
|  | continue to process the remaining names on the command line.  A memory | 
|  | allocation failure will abort the command.  If -t is specified, then the | 
|  | listed files or stdin will be tested as gzip files for integrity (without | 
|  | checking for a proper suffix), no output will be written, and no files | 
|  | will be deleted. | 
|  |  | 
|  | Like gzip, gun allows concatenated gzip streams and will decompress them, | 
|  | writing all of the uncompressed data to the output.  Unlike gzip, gun allows | 
|  | an empty file on input, and will produce no error writing an empty output | 
|  | file. | 
|  |  | 
|  | gun will also decompress files made by Unix compress, which uses LZW | 
|  | compression.  These files are automatically detected by virtue of their | 
|  | magic header bytes.  Since the end of Unix compress stream is marked by the | 
|  | end-of-file, they cannot be concatenated.  If a Unix compress stream is | 
|  | encountered in an input file, it is the last stream in that file. | 
|  |  | 
|  | Like gunzip and uncompress, the file attributes of the original compressed | 
|  | file are maintained in the final uncompressed file, to the extent that the | 
|  | user permissions allow it. | 
|  |  | 
|  | On my Mac OS X PowerPC G4, gun is almost twice as fast as gunzip (version | 
|  | 1.2.4) is on the same file, when gun is linked with zlib 1.2.2.  Also the | 
|  | LZW decompression provided by gun is about twice as fast as the standard | 
|  | Unix uncompress command. | 
|  | */ | 
|  |  | 
|  | /* external functions and related types and constants */ | 
|  | #include <stdio.h>          /* fprintf() */ | 
|  | #include <stdlib.h>         /* malloc(), free() */ | 
|  | #include <string.h>         /* strerror(), strcmp(), strlen(), memcpy() */ | 
|  | #include <errno.h>          /* errno */ | 
|  | #include <fcntl.h>          /* open() */ | 
|  | #include <unistd.h>         /* read(), write(), close(), chown(), unlink() */ | 
|  | #include <sys/types.h> | 
|  | #include <sys/stat.h>       /* stat(), chmod() */ | 
|  | #include <utime.h>          /* utime() */ | 
|  | #include "zlib.h"           /* inflateBackInit(), inflateBack(), */ | 
|  | /* inflateBackEnd(), crc32() */ | 
|  |  | 
|  | /* function declaration */ | 
|  | #define local static | 
|  |  | 
|  | /* buffer constants */ | 
|  | #define SIZE 32768U         /* input and output buffer sizes */ | 
|  | #define PIECE 16384         /* limits i/o chunks for 16-bit int case */ | 
|  |  | 
|  | /* structure for infback() to pass to input function in() -- it maintains the | 
|  | input file and a buffer of size SIZE */ | 
|  | struct ind { | 
|  | int infile; | 
|  | unsigned char *inbuf; | 
|  | }; | 
|  |  | 
|  | /* Load input buffer, assumed to be empty, and return bytes loaded and a | 
|  | pointer to them.  read() is called until the buffer is full, or until it | 
|  | returns end-of-file or error.  Return 0 on error. */ | 
|  | local unsigned in(void *in_desc, z_const unsigned char **buf) | 
|  | { | 
|  | int ret; | 
|  | unsigned len; | 
|  | unsigned char *next; | 
|  | struct ind *me = (struct ind *)in_desc; | 
|  |  | 
|  | next = me->inbuf; | 
|  | *buf = next; | 
|  | len = 0; | 
|  | do { | 
|  | ret = PIECE; | 
|  | if ((unsigned)ret > SIZE - len) | 
|  | ret = (int)(SIZE - len); | 
|  | ret = (int)read(me->infile, next, ret); | 
|  | if (ret == -1) { | 
|  | len = 0; | 
|  | break; | 
|  | } | 
|  | next += ret; | 
|  | len += ret; | 
|  | } while (ret != 0 && len < SIZE); | 
|  | return len; | 
|  | } | 
|  |  | 
|  | /* structure for infback() to pass to output function out() -- it maintains the | 
|  | output file, a running CRC-32 check on the output and the total number of | 
|  | bytes output, both for checking against the gzip trailer.  (The length in | 
|  | the gzip trailer is stored modulo 2^32, so it's ok if a long is 32 bits and | 
|  | the output is greater than 4 GB.) */ | 
|  | struct outd { | 
|  | int outfile; | 
|  | int check;                  /* true if checking crc and total */ | 
|  | unsigned long crc; | 
|  | unsigned long total; | 
|  | }; | 
|  |  | 
|  | /* Write output buffer and update the CRC-32 and total bytes written.  write() | 
|  | is called until all of the output is written or an error is encountered. | 
|  | On success out() returns 0.  For a write failure, out() returns 1.  If the | 
|  | output file descriptor is -1, then nothing is written. | 
|  | */ | 
|  | local int out(void *out_desc, unsigned char *buf, unsigned len) | 
|  | { | 
|  | int ret; | 
|  | struct outd *me = (struct outd *)out_desc; | 
|  |  | 
|  | if (me->check) { | 
|  | me->crc = crc32(me->crc, buf, len); | 
|  | me->total += len; | 
|  | } | 
|  | if (me->outfile != -1) | 
|  | do { | 
|  | ret = PIECE; | 
|  | if ((unsigned)ret > len) | 
|  | ret = (int)len; | 
|  | ret = (int)write(me->outfile, buf, ret); | 
|  | if (ret == -1) | 
|  | return 1; | 
|  | buf += ret; | 
|  | len -= ret; | 
|  | } while (len != 0); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* next input byte macro for use inside lunpipe() and gunpipe() */ | 
|  | #define NEXT() (have ? 0 : (have = in(indp, &next)), \ | 
|  | last = have ? (have--, (int)(*next++)) : -1) | 
|  |  | 
|  | /* memory for gunpipe() and lunpipe() -- | 
|  | the first 256 entries of prefix[] and suffix[] are never used, could | 
|  | have offset the index, but it's faster to waste the memory */ | 
|  | unsigned char inbuf[SIZE];              /* input buffer */ | 
|  | unsigned char outbuf[SIZE];             /* output buffer */ | 
|  | unsigned short prefix[65536];           /* index to LZW prefix string */ | 
|  | unsigned char suffix[65536];            /* one-character LZW suffix */ | 
|  | unsigned char match[65280 + 2];         /* buffer for reversed match or gzip | 
|  | 32K sliding window */ | 
|  |  | 
|  | /* throw out what's left in the current bits byte buffer (this is a vestigial | 
|  | aspect of the compressed data format derived from an implementation that | 
|  | made use of a special VAX machine instruction!) */ | 
|  | #define FLUSHCODE() \ | 
|  | do { \ | 
|  | left = 0; \ | 
|  | rem = 0; \ | 
|  | if (chunk > have) { \ | 
|  | chunk -= have; \ | 
|  | have = 0; \ | 
|  | if (NEXT() == -1) \ | 
|  | break; \ | 
|  | chunk--; \ | 
|  | if (chunk > have) { \ | 
|  | chunk = have = 0; \ | 
|  | break; \ | 
|  | } \ | 
|  | } \ | 
|  | have -= chunk; \ | 
|  | next += chunk; \ | 
|  | chunk = 0; \ | 
|  | } while (0) | 
|  |  | 
|  | /* Decompress a compress (LZW) file from indp to outfile.  The compress magic | 
|  | header (two bytes) has already been read and verified.  There are have bytes | 
|  | of buffered input at next.  strm is used for passing error information back | 
|  | to gunpipe(). | 
|  |  | 
|  | lunpipe() will return Z_OK on success, Z_BUF_ERROR for an unexpected end of | 
|  | file, read error, or write error (a write error indicated by strm->next_in | 
|  | not equal to Z_NULL), or Z_DATA_ERROR for invalid input. | 
|  | */ | 
|  | local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp, | 
|  | int outfile, z_stream *strm) | 
|  | { | 
|  | int last;                   /* last byte read by NEXT(), or -1 if EOF */ | 
|  | unsigned chunk;             /* bytes left in current chunk */ | 
|  | int left;                   /* bits left in rem */ | 
|  | unsigned rem;               /* unused bits from input */ | 
|  | int bits;                   /* current bits per code */ | 
|  | unsigned code;              /* code, table traversal index */ | 
|  | unsigned mask;              /* mask for current bits codes */ | 
|  | int max;                    /* maximum bits per code for this stream */ | 
|  | unsigned flags;             /* compress flags, then block compress flag */ | 
|  | unsigned end;               /* last valid entry in prefix/suffix tables */ | 
|  | unsigned temp;              /* current code */ | 
|  | unsigned prev;              /* previous code */ | 
|  | unsigned final;             /* last character written for previous code */ | 
|  | unsigned stack;             /* next position for reversed string */ | 
|  | unsigned outcnt;            /* bytes in output buffer */ | 
|  | struct outd outd;           /* output structure */ | 
|  | unsigned char *p; | 
|  |  | 
|  | /* set up output */ | 
|  | outd.outfile = outfile; | 
|  | outd.check = 0; | 
|  |  | 
|  | /* process remainder of compress header -- a flags byte */ | 
|  | flags = NEXT(); | 
|  | if (last == -1) | 
|  | return Z_BUF_ERROR; | 
|  | if (flags & 0x60) { | 
|  | strm->msg = (char *)"unknown lzw flags set"; | 
|  | return Z_DATA_ERROR; | 
|  | } | 
|  | max = flags & 0x1f; | 
|  | if (max < 9 || max > 16) { | 
|  | strm->msg = (char *)"lzw bits out of range"; | 
|  | return Z_DATA_ERROR; | 
|  | } | 
|  | if (max == 9)                           /* 9 doesn't really mean 9 */ | 
|  | max = 10; | 
|  | flags &= 0x80;                          /* true if block compress */ | 
|  |  | 
|  | /* clear table */ | 
|  | bits = 9; | 
|  | mask = 0x1ff; | 
|  | end = flags ? 256 : 255; | 
|  |  | 
|  | /* set up: get first 9-bit code, which is the first decompressed byte, but | 
|  | don't create a table entry until the next code */ | 
|  | if (NEXT() == -1)                       /* no compressed data is ok */ | 
|  | return Z_OK; | 
|  | final = prev = (unsigned)last;          /* low 8 bits of code */ | 
|  | if (NEXT() == -1)                       /* missing a bit */ | 
|  | return Z_BUF_ERROR; | 
|  | if (last & 1) {                         /* code must be < 256 */ | 
|  | strm->msg = (char *)"invalid lzw code"; | 
|  | return Z_DATA_ERROR; | 
|  | } | 
|  | rem = (unsigned)last >> 1;              /* remaining 7 bits */ | 
|  | left = 7; | 
|  | chunk = bits - 2;                       /* 7 bytes left in this chunk */ | 
|  | outbuf[0] = (unsigned char)final;       /* write first decompressed byte */ | 
|  | outcnt = 1; | 
|  |  | 
|  | /* decode codes */ | 
|  | stack = 0; | 
|  | for (;;) { | 
|  | /* if the table will be full after this, increment the code size */ | 
|  | if (end >= mask && bits < max) { | 
|  | FLUSHCODE(); | 
|  | bits++; | 
|  | mask <<= 1; | 
|  | mask++; | 
|  | } | 
|  |  | 
|  | /* get a code of length bits */ | 
|  | if (chunk == 0)                     /* decrement chunk modulo bits */ | 
|  | chunk = bits; | 
|  | code = rem;                         /* low bits of code */ | 
|  | if (NEXT() == -1) {                 /* EOF is end of compressed data */ | 
|  | /* write remaining buffered output */ | 
|  | if (outcnt && out(&outd, outbuf, outcnt)) { | 
|  | strm->next_in = outbuf;     /* signal write error */ | 
|  | return Z_BUF_ERROR; | 
|  | } | 
|  | return Z_OK; | 
|  | } | 
|  | code += (unsigned)last << left;     /* middle (or high) bits of code */ | 
|  | left += 8; | 
|  | chunk--; | 
|  | if (bits > left) {                  /* need more bits */ | 
|  | if (NEXT() == -1)               /* can't end in middle of code */ | 
|  | return Z_BUF_ERROR; | 
|  | code += (unsigned)last << left; /* high bits of code */ | 
|  | left += 8; | 
|  | chunk--; | 
|  | } | 
|  | code &= mask;                       /* mask to current code length */ | 
|  | left -= bits;                       /* number of unused bits */ | 
|  | rem = (unsigned)last >> (8 - left); /* unused bits from last byte */ | 
|  |  | 
|  | /* process clear code (256) */ | 
|  | if (code == 256 && flags) { | 
|  | FLUSHCODE(); | 
|  | bits = 9;                       /* initialize bits and mask */ | 
|  | mask = 0x1ff; | 
|  | end = 255;                      /* empty table */ | 
|  | continue;                       /* get next code */ | 
|  | } | 
|  |  | 
|  | /* special code to reuse last match */ | 
|  | temp = code;                        /* save the current code */ | 
|  | if (code > end) { | 
|  | /* Be picky on the allowed code here, and make sure that the code | 
|  | we drop through (prev) will be a valid index so that random | 
|  | input does not cause an exception.  The code != end + 1 check is | 
|  | empirically derived, and not checked in the original uncompress | 
|  | code.  If this ever causes a problem, that check could be safely | 
|  | removed.  Leaving this check in greatly improves gun's ability | 
|  | to detect random or corrupted input after a compress header. | 
|  | In any case, the prev > end check must be retained. */ | 
|  | if (code != end + 1 || prev > end) { | 
|  | strm->msg = (char *)"invalid lzw code"; | 
|  | return Z_DATA_ERROR; | 
|  | } | 
|  | match[stack++] = (unsigned char)final; | 
|  | code = prev; | 
|  | } | 
|  |  | 
|  | /* walk through linked list to generate output in reverse order */ | 
|  | p = match + stack; | 
|  | while (code >= 256) { | 
|  | *p++ = suffix[code]; | 
|  | code = prefix[code]; | 
|  | } | 
|  | stack = p - match; | 
|  | match[stack++] = (unsigned char)code; | 
|  | final = code; | 
|  |  | 
|  | /* link new table entry */ | 
|  | if (end < mask) { | 
|  | end++; | 
|  | prefix[end] = (unsigned short)prev; | 
|  | suffix[end] = (unsigned char)final; | 
|  | } | 
|  |  | 
|  | /* set previous code for next iteration */ | 
|  | prev = temp; | 
|  |  | 
|  | /* write output in forward order */ | 
|  | while (stack > SIZE - outcnt) { | 
|  | while (outcnt < SIZE) | 
|  | outbuf[outcnt++] = match[--stack]; | 
|  | if (out(&outd, outbuf, outcnt)) { | 
|  | strm->next_in = outbuf; /* signal write error */ | 
|  | return Z_BUF_ERROR; | 
|  | } | 
|  | outcnt = 0; | 
|  | } | 
|  | p = match + stack; | 
|  | do { | 
|  | outbuf[outcnt++] = *--p; | 
|  | } while (p > match); | 
|  | stack = 0; | 
|  |  | 
|  | /* loop for next code with final and prev as the last match, rem and | 
|  | left provide the first 0..7 bits of the next code, end is the last | 
|  | valid table entry */ | 
|  | } | 
|  | } | 
|  |  | 
|  | /* Decompress a gzip file from infile to outfile.  strm is assumed to have been | 
|  | successfully initialized with inflateBackInit().  The input file may consist | 
|  | of a series of gzip streams, in which case all of them will be decompressed | 
|  | to the output file.  If outfile is -1, then the gzip stream(s) integrity is | 
|  | checked and nothing is written. | 
|  |  | 
|  | The return value is a zlib error code: Z_MEM_ERROR if out of memory, | 
|  | Z_DATA_ERROR if the header or the compressed data is invalid, or if the | 
|  | trailer CRC-32 check or length doesn't match, Z_BUF_ERROR if the input ends | 
|  | prematurely or a write error occurs, or Z_ERRNO if junk (not a another gzip | 
|  | stream) follows a valid gzip stream. | 
|  | */ | 
|  | local int gunpipe(z_stream *strm, int infile, int outfile) | 
|  | { | 
|  | int ret, first, last; | 
|  | unsigned have, flags, len; | 
|  | z_const unsigned char *next = NULL; | 
|  | struct ind ind, *indp; | 
|  | struct outd outd; | 
|  |  | 
|  | /* setup input buffer */ | 
|  | ind.infile = infile; | 
|  | ind.inbuf = inbuf; | 
|  | indp = &ind; | 
|  |  | 
|  | /* decompress concatenated gzip streams */ | 
|  | have = 0;                               /* no input data read in yet */ | 
|  | first = 1;                              /* looking for first gzip header */ | 
|  | strm->next_in = Z_NULL;                 /* so Z_BUF_ERROR means EOF */ | 
|  | for (;;) { | 
|  | /* look for the two magic header bytes for a gzip stream */ | 
|  | if (NEXT() == -1) { | 
|  | ret = Z_OK; | 
|  | break;                          /* empty gzip stream is ok */ | 
|  | } | 
|  | if (last != 31 || (NEXT() != 139 && last != 157)) { | 
|  | strm->msg = (char *)"incorrect header check"; | 
|  | ret = first ? Z_DATA_ERROR : Z_ERRNO; | 
|  | break;                          /* not a gzip or compress header */ | 
|  | } | 
|  | first = 0;                          /* next non-header is junk */ | 
|  |  | 
|  | /* process a compress (LZW) file -- can't be concatenated after this */ | 
|  | if (last == 157) { | 
|  | ret = lunpipe(have, next, indp, outfile, strm); | 
|  | break; | 
|  | } | 
|  |  | 
|  | /* process remainder of gzip header */ | 
|  | ret = Z_BUF_ERROR; | 
|  | if (NEXT() != 8) {                  /* only deflate method allowed */ | 
|  | if (last == -1) break; | 
|  | strm->msg = (char *)"unknown compression method"; | 
|  | ret = Z_DATA_ERROR; | 
|  | break; | 
|  | } | 
|  | flags = NEXT();                     /* header flags */ | 
|  | NEXT();                             /* discard mod time, xflgs, os */ | 
|  | NEXT(); | 
|  | NEXT(); | 
|  | NEXT(); | 
|  | NEXT(); | 
|  | NEXT(); | 
|  | if (last == -1) break; | 
|  | if (flags & 0xe0) { | 
|  | strm->msg = (char *)"unknown header flags set"; | 
|  | ret = Z_DATA_ERROR; | 
|  | break; | 
|  | } | 
|  | if (flags & 4) {                    /* extra field */ | 
|  | len = NEXT(); | 
|  | len += (unsigned)(NEXT()) << 8; | 
|  | if (last == -1) break; | 
|  | while (len > have) { | 
|  | len -= have; | 
|  | have = 0; | 
|  | if (NEXT() == -1) break; | 
|  | len--; | 
|  | } | 
|  | if (last == -1) break; | 
|  | have -= len; | 
|  | next += len; | 
|  | } | 
|  | if (flags & 8)                      /* file name */ | 
|  | while (NEXT() != 0 && last != -1) | 
|  | ; | 
|  | if (flags & 16)                     /* comment */ | 
|  | while (NEXT() != 0 && last != -1) | 
|  | ; | 
|  | if (flags & 2) {                    /* header crc */ | 
|  | NEXT(); | 
|  | NEXT(); | 
|  | } | 
|  | if (last == -1) break; | 
|  |  | 
|  | /* set up output */ | 
|  | outd.outfile = outfile; | 
|  | outd.check = 1; | 
|  | outd.crc = crc32(0L, Z_NULL, 0); | 
|  | outd.total = 0; | 
|  |  | 
|  | /* decompress data to output */ | 
|  | strm->next_in = next; | 
|  | strm->avail_in = have; | 
|  | ret = inflateBack(strm, in, indp, out, &outd); | 
|  | if (ret != Z_STREAM_END) break; | 
|  | next = strm->next_in; | 
|  | have = strm->avail_in; | 
|  | strm->next_in = Z_NULL;             /* so Z_BUF_ERROR means EOF */ | 
|  |  | 
|  | /* check trailer */ | 
|  | ret = Z_BUF_ERROR; | 
|  | if (NEXT() != (int)(outd.crc & 0xff) || | 
|  | NEXT() != (int)((outd.crc >> 8) & 0xff) || | 
|  | NEXT() != (int)((outd.crc >> 16) & 0xff) || | 
|  | NEXT() != (int)((outd.crc >> 24) & 0xff)) { | 
|  | /* crc error */ | 
|  | if (last != -1) { | 
|  | strm->msg = (char *)"incorrect data check"; | 
|  | ret = Z_DATA_ERROR; | 
|  | } | 
|  | break; | 
|  | } | 
|  | if (NEXT() != (int)(outd.total & 0xff) || | 
|  | NEXT() != (int)((outd.total >> 8) & 0xff) || | 
|  | NEXT() != (int)((outd.total >> 16) & 0xff) || | 
|  | NEXT() != (int)((outd.total >> 24) & 0xff)) { | 
|  | /* length error */ | 
|  | if (last != -1) { | 
|  | strm->msg = (char *)"incorrect length check"; | 
|  | ret = Z_DATA_ERROR; | 
|  | } | 
|  | break; | 
|  | } | 
|  |  | 
|  | /* go back and look for another gzip stream */ | 
|  | } | 
|  |  | 
|  | /* clean up and return */ | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* Copy file attributes, from -> to, as best we can.  This is best effort, so | 
|  | no errors are reported.  The mode bits, including suid, sgid, and the sticky | 
|  | bit are copied (if allowed), the owner's user id and group id are copied | 
|  | (again if allowed), and the access and modify times are copied. */ | 
|  | local void copymeta(char *from, char *to) | 
|  | { | 
|  | struct stat was; | 
|  | struct utimbuf when; | 
|  |  | 
|  | /* get all of from's Unix meta data, return if not a regular file */ | 
|  | if (stat(from, &was) != 0 || (was.st_mode & S_IFMT) != S_IFREG) | 
|  | return; | 
|  |  | 
|  | /* set to's mode bits, ignore errors */ | 
|  | (void)chmod(to, was.st_mode & 07777); | 
|  |  | 
|  | /* copy owner's user and group, ignore errors */ | 
|  | (void)chown(to, was.st_uid, was.st_gid); | 
|  |  | 
|  | /* copy access and modify times, ignore errors */ | 
|  | when.actime = was.st_atime; | 
|  | when.modtime = was.st_mtime; | 
|  | (void)utime(to, &when); | 
|  | } | 
|  |  | 
|  | /* Decompress the file inname to the file outnname, of if test is true, just | 
|  | decompress without writing and check the gzip trailer for integrity.  If | 
|  | inname is NULL or an empty string, read from stdin.  If outname is NULL or | 
|  | an empty string, write to stdout.  strm is a pre-initialized inflateBack | 
|  | structure.  When appropriate, copy the file attributes from inname to | 
|  | outname. | 
|  |  | 
|  | gunzip() returns 1 if there is an out-of-memory error or an unexpected | 
|  | return code from gunpipe().  Otherwise it returns 0. | 
|  | */ | 
|  | local int gunzip(z_stream *strm, char *inname, char *outname, int test) | 
|  | { | 
|  | int ret; | 
|  | int infile, outfile; | 
|  |  | 
|  | /* open files */ | 
|  | if (inname == NULL || *inname == 0) { | 
|  | inname = "-"; | 
|  | infile = 0;     /* stdin */ | 
|  | } | 
|  | else { | 
|  | infile = open(inname, O_RDONLY, 0); | 
|  | if (infile == -1) { | 
|  | fprintf(stderr, "gun cannot open %s\n", inname); | 
|  | return 0; | 
|  | } | 
|  | } | 
|  | if (test) | 
|  | outfile = -1; | 
|  | else if (outname == NULL || *outname == 0) { | 
|  | outname = "-"; | 
|  | outfile = 1;    /* stdout */ | 
|  | } | 
|  | else { | 
|  | outfile = open(outname, O_CREAT | O_TRUNC | O_WRONLY, 0666); | 
|  | if (outfile == -1) { | 
|  | close(infile); | 
|  | fprintf(stderr, "gun cannot create %s\n", outname); | 
|  | return 0; | 
|  | } | 
|  | } | 
|  | errno = 0; | 
|  |  | 
|  | /* decompress */ | 
|  | ret = gunpipe(strm, infile, outfile); | 
|  | if (outfile > 2) close(outfile); | 
|  | if (infile > 2) close(infile); | 
|  |  | 
|  | /* interpret result */ | 
|  | switch (ret) { | 
|  | case Z_OK: | 
|  | case Z_ERRNO: | 
|  | if (infile > 2 && outfile > 2) { | 
|  | copymeta(inname, outname);          /* copy attributes */ | 
|  | unlink(inname); | 
|  | } | 
|  | if (ret == Z_ERRNO) | 
|  | fprintf(stderr, "gun warning: trailing garbage ignored in %s\n", | 
|  | inname); | 
|  | break; | 
|  | case Z_DATA_ERROR: | 
|  | if (outfile > 2) unlink(outname); | 
|  | fprintf(stderr, "gun data error on %s: %s\n", inname, strm->msg); | 
|  | break; | 
|  | case Z_MEM_ERROR: | 
|  | if (outfile > 2) unlink(outname); | 
|  | fprintf(stderr, "gun out of memory error--aborting\n"); | 
|  | return 1; | 
|  | case Z_BUF_ERROR: | 
|  | if (outfile > 2) unlink(outname); | 
|  | if (strm->next_in != Z_NULL) { | 
|  | fprintf(stderr, "gun write error on %s: %s\n", | 
|  | outname, strerror(errno)); | 
|  | } | 
|  | else if (errno) { | 
|  | fprintf(stderr, "gun read error on %s: %s\n", | 
|  | inname, strerror(errno)); | 
|  | } | 
|  | else { | 
|  | fprintf(stderr, "gun unexpected end of file on %s\n", | 
|  | inname); | 
|  | } | 
|  | break; | 
|  | default: | 
|  | if (outfile > 2) unlink(outname); | 
|  | fprintf(stderr, "gun internal error--aborting\n"); | 
|  | return 1; | 
|  | } | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* Process the gun command line arguments.  See the command syntax near the | 
|  | beginning of this source file. */ | 
|  | int main(int argc, char **argv) | 
|  | { | 
|  | int ret, len, test; | 
|  | char *outname; | 
|  | unsigned char *window; | 
|  | z_stream strm; | 
|  |  | 
|  | /* initialize inflateBack state for repeated use */ | 
|  | window = match;                         /* reuse LZW match buffer */ | 
|  | strm.zalloc = Z_NULL; | 
|  | strm.zfree = Z_NULL; | 
|  | strm.opaque = Z_NULL; | 
|  | ret = inflateBackInit(&strm, 15, window); | 
|  | if (ret != Z_OK) { | 
|  | fprintf(stderr, "gun out of memory error--aborting\n"); | 
|  | return 1; | 
|  | } | 
|  |  | 
|  | /* decompress each file to the same name with the suffix removed */ | 
|  | argc--; | 
|  | argv++; | 
|  | test = 0; | 
|  | if (argc && strcmp(*argv, "-h") == 0) { | 
|  | fprintf(stderr, "gun 1.6 (17 Jan 2010)\n"); | 
|  | fprintf(stderr, "Copyright (C) 2003-2010 Mark Adler\n"); | 
|  | fprintf(stderr, "usage: gun [-t] [file1.gz [file2.Z ...]]\n"); | 
|  | return 0; | 
|  | } | 
|  | if (argc && strcmp(*argv, "-t") == 0) { | 
|  | test = 1; | 
|  | argc--; | 
|  | argv++; | 
|  | } | 
|  | if (argc) | 
|  | do { | 
|  | if (test) | 
|  | outname = NULL; | 
|  | else { | 
|  | len = (int)strlen(*argv); | 
|  | if (strcmp(*argv + len - 3, ".gz") == 0 || | 
|  | strcmp(*argv + len - 3, "-gz") == 0) | 
|  | len -= 3; | 
|  | else if (strcmp(*argv + len - 2, ".z") == 0 || | 
|  | strcmp(*argv + len - 2, "-z") == 0 || | 
|  | strcmp(*argv + len - 2, "_z") == 0 || | 
|  | strcmp(*argv + len - 2, ".Z") == 0) | 
|  | len -= 2; | 
|  | else { | 
|  | fprintf(stderr, "gun error: no gz type on %s--skipping\n", | 
|  | *argv); | 
|  | continue; | 
|  | } | 
|  | outname = malloc(len + 1); | 
|  | if (outname == NULL) { | 
|  | fprintf(stderr, "gun out of memory error--aborting\n"); | 
|  | ret = 1; | 
|  | break; | 
|  | } | 
|  | memcpy(outname, *argv, len); | 
|  | outname[len] = 0; | 
|  | } | 
|  | ret = gunzip(&strm, *argv, outname, test); | 
|  | if (outname != NULL) free(outname); | 
|  | if (ret) break; | 
|  | } while (argv++, --argc); | 
|  | else | 
|  | ret = gunzip(&strm, NULL, NULL, test); | 
|  |  | 
|  | /* clean up */ | 
|  | inflateBackEnd(&strm); | 
|  | return ret; | 
|  | } |