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/StormLib/stormlib/zlib/minigzip.c

http://ghostcb.googlecode.com/
C | 322 lines | 228 code | 46 blank | 48 comment | 78 complexity | 48595cb11343923715e0f81a4a453382 MD5 | raw file
  1/* minigzip.c -- simulate gzip using the zlib compression library
  2 * Copyright (C) 1995-2005 Jean-loup Gailly.
  3 * For conditions of distribution and use, see copyright notice in zlib.h
  4 */
  5
  6/*
  7 * minigzip is a minimal implementation of the gzip utility. This is
  8 * only an example of using zlib and isn't meant to replace the
  9 * full-featured gzip. No attempt is made to deal with file systems
 10 * limiting names to 14 or 8+3 characters, etc... Error checking is
 11 * very limited. So use minigzip only for testing; use gzip for the
 12 * real thing. On MSDOS, use only on file names without extension
 13 * or in pipe mode.
 14 */
 15
 16/* @(#) $Id$ */
 17
 18#include <stdio.h>
 19#include "zlib.h"
 20
 21#ifdef STDC
 22#  include <string.h>
 23#  include <stdlib.h>
 24#endif
 25
 26#ifdef USE_MMAP
 27#  include <sys/types.h>
 28#  include <sys/mman.h>
 29#  include <sys/stat.h>
 30#endif
 31
 32#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
 33#  include <fcntl.h>
 34#  include <io.h>
 35#  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
 36#else
 37#  define SET_BINARY_MODE(file)
 38#endif
 39
 40#ifdef VMS
 41#  define unlink delete
 42#  define GZ_SUFFIX "-gz"
 43#endif
 44#ifdef RISCOS
 45#  define unlink remove
 46#  define GZ_SUFFIX "-gz"
 47#  define fileno(file) file->__file
 48#endif
 49#if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
 50#  include <unix.h> /* for fileno */
 51#endif
 52
 53#ifndef WIN32 /* unlink already in stdio.h for WIN32 */
 54  extern int unlink OF((const char *));
 55#endif
 56
 57#ifndef GZ_SUFFIX
 58#  define GZ_SUFFIX ".gz"
 59#endif
 60#define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1)
 61
 62#define BUFLEN      16384
 63#define MAX_NAME_LEN 1024
 64
 65#ifdef MAXSEG_64K
 66#  define local static
 67   /* Needed for systems with limitation on stack size. */
 68#else
 69#  define local
 70#endif
 71
 72char *prog;
 73
 74void error            OF((const char *msg));
 75void gz_compress      OF((FILE   *in, gzFile out));
 76#ifdef USE_MMAP
 77int  gz_compress_mmap OF((FILE   *in, gzFile out));
 78#endif
 79void gz_uncompress    OF((gzFile in, FILE   *out));
 80void file_compress    OF((char  *file, char *mode));
 81void file_uncompress  OF((char  *file));
 82int  main             OF((int argc, char *argv[]));
 83
 84/* ===========================================================================
 85 * Display error message and exit
 86 */
 87void error(msg)
 88    const char *msg;
 89{
 90    fprintf(stderr, "%s: %s\n", prog, msg);
 91    exit(1);
 92}
 93
 94/* ===========================================================================
 95 * Compress input to output then close both files.
 96 */
 97
 98void gz_compress(in, out)
 99    FILE   *in;
100    gzFile out;
101{
102    local char buf[BUFLEN];
103    int len;
104    int err;
105
106#ifdef USE_MMAP
107    /* Try first compressing with mmap. If mmap fails (minigzip used in a
108     * pipe), use the normal fread loop.
109     */
110    if (gz_compress_mmap(in, out) == Z_OK) return;
111#endif
112    for (;;) {
113        len = (int)fread(buf, 1, sizeof(buf), in);
114        if (ferror(in)) {
115            perror("fread");
116            exit(1);
117        }
118        if (len == 0) break;
119
120        if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err));
121    }
122    fclose(in);
123    if (gzclose(out) != Z_OK) error("failed gzclose");
124}
125
126#ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */
127
128/* Try compressing the input file at once using mmap. Return Z_OK if
129 * if success, Z_ERRNO otherwise.
130 */
131int gz_compress_mmap(in, out)
132    FILE   *in;
133    gzFile out;
134{
135    int len;
136    int err;
137    int ifd = fileno(in);
138    caddr_t buf;    /* mmap'ed buffer for the entire input file */
139    off_t buf_len;  /* length of the input file */
140    struct stat sb;
141
142    /* Determine the size of the file, needed for mmap: */
143    if (fstat(ifd, &sb) < 0) return Z_ERRNO;
144    buf_len = sb.st_size;
145    if (buf_len <= 0) return Z_ERRNO;
146
147    /* Now do the actual mmap: */
148    buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0);
149    if (buf == (caddr_t)(-1)) return Z_ERRNO;
150
151    /* Compress the whole file at once: */
152    len = gzwrite(out, (char *)buf, (unsigned)buf_len);
153
154    if (len != (int)buf_len) error(gzerror(out, &err));
155
156    munmap(buf, buf_len);
157    fclose(in);
158    if (gzclose(out) != Z_OK) error("failed gzclose");
159    return Z_OK;
160}
161#endif /* USE_MMAP */
162
163/* ===========================================================================
164 * Uncompress input to output then close both files.
165 */
166void gz_uncompress(in, out)
167    gzFile in;
168    FILE   *out;
169{
170    local char buf[BUFLEN];
171    int len;
172    int err;
173
174    for (;;) {
175        len = gzread(in, buf, sizeof(buf));
176        if (len < 0) error (gzerror(in, &err));
177        if (len == 0) break;
178
179        if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
180            error("failed fwrite");
181        }
182    }
183    if (fclose(out)) error("failed fclose");
184
185    if (gzclose(in) != Z_OK) error("failed gzclose");
186}
187
188
189/* ===========================================================================
190 * Compress the given file: create a corresponding .gz file and remove the
191 * original.
192 */
193void file_compress(file, mode)
194    char  *file;
195    char  *mode;
196{
197    local char outfile[MAX_NAME_LEN];
198    FILE  *in;
199    gzFile out;
200
201    strcpy(outfile, file);
202    strcat(outfile, GZ_SUFFIX);
203
204    in = fopen(file, "rb");
205    if (in == NULL) {
206        perror(file);
207        exit(1);
208    }
209    out = gzopen(outfile, mode);
210    if (out == NULL) {
211        fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);
212        exit(1);
213    }
214    gz_compress(in, out);
215
216    unlink(file);
217}
218
219
220/* ===========================================================================
221 * Uncompress the given file and remove the original.
222 */
223void file_uncompress(file)
224    char  *file;
225{
226    local char buf[MAX_NAME_LEN];
227    char *infile, *outfile;
228    FILE  *out;
229    gzFile in;
230    uInt len = (uInt)strlen(file);
231
232    strcpy(buf, file);
233
234    if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {
235        infile = file;
236        outfile = buf;
237        outfile[len-3] = '\0';
238    } else {
239        outfile = file;
240        infile = buf;
241        strcat(infile, GZ_SUFFIX);
242    }
243    in = gzopen(infile, "rb");
244    if (in == NULL) {
245        fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);
246        exit(1);
247    }
248    out = fopen(outfile, "wb");
249    if (out == NULL) {
250        perror(file);
251        exit(1);
252    }
253
254    gz_uncompress(in, out);
255
256    unlink(infile);
257}
258
259
260/* ===========================================================================
261 * Usage:  minigzip [-d] [-f] [-h] [-r] [-1 to -9] [files...]
262 *   -d : decompress
263 *   -f : compress with Z_FILTERED
264 *   -h : compress with Z_HUFFMAN_ONLY
265 *   -r : compress with Z_RLE
266 *   -1 to -9 : compression level
267 */
268
269int main(argc, argv)
270    int argc;
271    char *argv[];
272{
273    int uncompr = 0;
274    gzFile file;
275    char outmode[20];
276
277    strcpy(outmode, "wb6 ");
278
279    prog = argv[0];
280    argc--, argv++;
281
282    while (argc > 0) {
283      if (strcmp(*argv, "-d") == 0)
284        uncompr = 1;
285      else if (strcmp(*argv, "-f") == 0)
286        outmode[3] = 'f';
287      else if (strcmp(*argv, "-h") == 0)
288        outmode[3] = 'h';
289      else if (strcmp(*argv, "-r") == 0)
290        outmode[3] = 'R';
291      else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' &&
292               (*argv)[2] == 0)
293        outmode[2] = (*argv)[1];
294      else
295        break;
296      argc--, argv++;
297    }
298    if (outmode[3] == ' ')
299        outmode[3] = 0;
300    if (argc == 0) {
301        SET_BINARY_MODE(stdin);
302        SET_BINARY_MODE(stdout);
303        if (uncompr) {
304            file = gzdopen(fileno(stdin), "rb");
305            if (file == NULL) error("can't gzdopen stdin");
306            gz_uncompress(file, stdout);
307        } else {
308            file = gzdopen(fileno(stdout), outmode);
309            if (file == NULL) error("can't gzdopen stdout");
310            gz_compress(stdin, file);
311        }
312    } else {
313        do {
314            if (uncompr) {
315                file_uncompress(*argv);
316            } else {
317                file_compress(*argv, outmode);
318            }
319        } while (argv++, --argc);
320    }
321    return 0;
322}