zlib/minigzip.c

   1 /* minigzip.c -- simulate gzip using the zlib compression library
   2  * Copyright (C) 1995-2006, 2010 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: minigzip.c,v 1.1.1.2 2002/03/11 21:53:26 tromey Exp $ */
  17
  18 #include "zlib.h"
  19 #include <stdio.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 #  ifdef UNDER_CE
  36 #    include <stdlib.h>
  37 #  endif
  38 #  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
  39 #else
  40 #  define SET_BINARY_MODE(file)
  41 #endif
  42
  43 #ifdef VMS
  44 #  define unlink delete
  45 #  define GZ_SUFFIX "-gz"
  46 #endif
  47 #ifdef RISCOS
  48 #  define unlink remove
  49 #  define GZ_SUFFIX "-gz"
  50 #  define fileno(file) file->__file
  51 #endif
  52 #if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
  53 #  include <unix.h> /* for fileno */
  54 #endif
  55
  56 #if !defined(Z_HAVE_UNISTD_H) && !defined(_LARGEFILE64_SOURCE)
  57 #ifndef WIN32 /* unlink already in stdio.h for WIN32 */
  58   extern int unlink OF((const char *));
  59 #endif
  60 #endif
  61
  62 #if defined(UNDER_CE)
  63 #  include <windows.h>
  64 #  define perror(s) pwinerror(s)
  65
  66 /* Map the Windows error number in ERROR to a locale-dependent error
  67    message string and return a pointer to it.  Typically, the values
  68    for ERROR come from GetLastError.
  69
  70    The string pointed to shall not be modified by the application,
  71    but may be overwritten by a subsequent call to strwinerror
  72
  73    The strwinerror function does not change the current setting
  74    of GetLastError.  */
  75
  76 static char *strwinerror (error)
  77      DWORD error;
  78 {
  79     static char buf[1024];
  80
  81     wchar_t *msgbuf;
  82     DWORD lasterr = GetLastError();
  83     DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
  84         | FORMAT_MESSAGE_ALLOCATE_BUFFER,
  85         NULL,
  86         error,
  87         0, /* Default language */
  88         (LPVOID)&msgbuf,
  89         0,
  90         NULL);
  91     if (chars != 0) {
  92         /* If there is an \r\n appended, zap it.  */
  93         if (chars >= 2
  94             && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
  95             chars -= 2;
  96             msgbuf[chars] = 0;
  97         }
  98
  99         if (chars > sizeof (buf) - 1) {
 100             chars = sizeof (buf) - 1;
 101             msgbuf[chars] = 0;
 102         }
 103
 104         wcstombs(buf, msgbuf, chars + 1);
 105         LocalFree(msgbuf);
 106     }
 107     else {
 108         sprintf(buf, "unknown win32 error (%ld)", error);
 109     }
 110
 111     SetLastError(lasterr);
 112     return buf;
 113 }
 114
 115 static void pwinerror (s)
 116     const char *s;
 117 {
 118     if (s && *s)
 119         fprintf(stderr, "%s: %s\n", s, strwinerror(GetLastError ()));
 120     else
 121         fprintf(stderr, "%s\n", strwinerror(GetLastError ()));
 122 }
 123
 124 #endif /* UNDER_CE */
 125
 126 #ifndef GZ_SUFFIX
 127 #  define GZ_SUFFIX ".gz"
 128 #endif
 129 #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1)
 130
 131 #define BUFLEN      16384
 132 #define MAX_NAME_LEN 1024
 133
 134 #ifdef MAXSEG_64K
 135 #  define local static
 136    /* Needed for systems with limitation on stack size. */
 137 #else
 138 #  define local
 139 #endif
 140
 141 char *prog;
 142
 143 void error            OF((const char *msg));
 144 void gz_compress      OF((FILE   *in, gzFile out));
 145 #ifdef USE_MMAP
 146 int  gz_compress_mmap OF((FILE   *in, gzFile out));
 147 #endif
 148 void gz_uncompress    OF((gzFile in, FILE   *out));
 149 void file_compress    OF((char  *file, char *mode));
 150 void file_uncompress  OF((char  *file));
 151 int  main             OF((int argc, char *argv[]));
 152
 153 /* ===========================================================================
 154  * Display error message and exit
 155  */
 156 void error(msg)
 157     const char *msg;
 158 {
 159     fprintf(stderr, "%s: %s\n", prog, msg);
 160     exit(1);
 161 }
 162
 163 /* ===========================================================================
 164  * Compress input to output then close both files.
 165  */
 166
 167 void gz_compress(in, out)
 168     FILE   *in;
 169     gzFile out;
 170 {
 171     local char buf[BUFLEN];
 172     int len;
 173     int err;
 174
 175 #ifdef USE_MMAP
 176     /* Try first compressing with mmap. If mmap fails (minigzip used in a
 177      * pipe), use the normal fread loop.
 178      */
 179     if (gz_compress_mmap(in, out) == Z_OK) return;
 180 #endif
 181     for (;;) {
 182         len = (int)fread(buf, 1, sizeof(buf), in);
 183         if (ferror(in)) {
 184             perror("fread");
 185             exit(1);
 186         }
 187         if (len == 0) break;
 188
 189         if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err));
 190     }
 191     fclose(in);
 192     if (gzclose(out) != Z_OK) error("failed gzclose");
 193 }
 194
 195 #ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */
 196
 197 /* Try compressing the input file at once using mmap. Return Z_OK if
 198  * if success, Z_ERRNO otherwise.
 199  */
 200 int gz_compress_mmap(in, out)
 201     FILE   *in;
 202     gzFile out;
 203 {
 204     int len;
 205     int err;
 206     int ifd = fileno(in);
 207     caddr_t buf;    /* mmap'ed buffer for the entire input file */
 208     off_t buf_len;  /* length of the input file */
 209     struct stat sb;
 210
 211     /* Determine the size of the file, needed for mmap: */
 212     if (fstat(ifd, &sb) < 0) return Z_ERRNO;
 213     buf_len = sb.st_size;
 214     if (buf_len <= 0) return Z_ERRNO;
 215
 216     /* Now do the actual mmap: */
 217     buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0);
 218     if (buf == (caddr_t)(-1)) return Z_ERRNO;
 219
 220     /* Compress the whole file at once: */
 221     len = gzwrite(out, (char *)buf, (unsigned)buf_len);
 222
 223     if (len != (int)buf_len) error(gzerror(out, &err));
 224
 225     munmap(buf, buf_len);
 226     fclose(in);
 227     if (gzclose(out) != Z_OK) error("failed gzclose");
 228     return Z_OK;
 229 }
 230 #endif /* USE_MMAP */
 231
 232 /* ===========================================================================
 233  * Uncompress input to output then close both files.
 234  */
 235 void gz_uncompress(in, out)
 236     gzFile in;
 237     FILE   *out;
 238 {
 239     local char buf[BUFLEN];
 240     int len;
 241     int err;
 242
 243     for (;;) {
 244         len = gzread(in, buf, sizeof(buf));
 245         if (len < 0) error (gzerror(in, &err));
 246         if (len == 0) break;
 247
 248         if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
 249             error("failed fwrite");
 250         }
 251     }
 252     if (fclose(out)) error("failed fclose");
 253
 254     if (gzclose(in) != Z_OK) error("failed gzclose");
 255 }
 256
 257
 258 /* ===========================================================================
 259  * Compress the given file: create a corresponding .gz file and remove the
 260  * original.
 261  */
 262 void file_compress(file, mode)
 263     char  *file;
 264     char  *mode;
 265 {
 266     local char outfile[MAX_NAME_LEN];
 267     FILE  *in;
 268     gzFile out;
 269
 270     if (strlen(file) + strlen(GZ_SUFFIX) >= sizeof(outfile)) {
 271         fprintf(stderr, "%s: filename too long\n", prog);
 272         exit(1);
 273     }
 274
 275     strcpy(outfile, file);
 276     strcat(outfile, GZ_SUFFIX);
 277
 278     in = fopen(file, "rb");
 279     if (in == NULL) {
 280         perror(file);
 281         exit(1);
 282     }
 283     out = gzopen(outfile, mode);
 284     if (out == NULL) {
 285         fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);
 286         exit(1);
 287     }
 288     gz_compress(in, out);
 289
 290     unlink(file);
 291 }
 292
 293
 294 /* ===========================================================================
 295  * Uncompress the given file and remove the original.
 296  */
 297 void file_uncompress(file)
 298     char  *file;
 299 {
 300     local char buf[MAX_NAME_LEN];
 301     char *infile, *outfile;
 302     FILE  *out;
 303     gzFile in;
 304     size_t len = strlen(file);
 305
 306     if (len + strlen(GZ_SUFFIX) >= sizeof(buf)) {
 307         fprintf(stderr, "%s: filename too long\n", prog);
 308         exit(1);
 309     }
 310
 311     strcpy(buf, file);
 312
 313     if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {
 314         infile = file;
 315         outfile = buf;
 316         outfile[len-3] = '\0';
 317     } else {
 318         outfile = file;
 319         infile = buf;
 320         strcat(infile, GZ_SUFFIX);
 321     }
 322     in = gzopen(infile, "rb");
 323     if (in == NULL) {
 324         fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);
 325         exit(1);
 326     }
 327     out = fopen(outfile, "wb");
 328     if (out == NULL) {
 329         perror(file);
 330         exit(1);
 331     }
 332
 333     gz_uncompress(in, out);
 334
 335     unlink(infile);
 336 }
 337
 338
 339 /* ===========================================================================
 340  * Usage:  minigzip [-c] [-d] [-f] [-h] [-r] [-1 to -9] [files...]
 341  *   -c : write to standard output
 342  *   -d : decompress
 343  *   -f : compress with Z_FILTERED
 344  *   -h : compress with Z_HUFFMAN_ONLY
 345  *   -r : compress with Z_RLE
 346  *   -1 to -9 : compression level
 347  */
 348
 349 int main(argc, argv)
 350     int argc;
 351     char *argv[];
 352 {
 353     int copyout = 0;
 354     int uncompr = 0;
 355     gzFile file;
 356     char *bname, outmode[20];
 357
 358     strcpy(outmode, "wb6 ");
 359
 360     prog = argv[0];
 361     bname = strrchr(argv[0], '/');
 362     if (bname)
 363       bname++;
 364     else
 365       bname = argv[0];
 366     argc--, argv++;
 367
 368     if (!strcmp(bname, "gunzip"))
 369       uncompr = 1;
 370     else if (!strcmp(bname, "zcat"))
 371       copyout = uncompr = 1;
 372
 373     while (argc > 0) {
 374       if (strcmp(*argv, "-c") == 0)
 375         copyout = 1;
 376       else if (strcmp(*argv, "-d") == 0)
 377         uncompr = 1;
 378       else if (strcmp(*argv, "-f") == 0)
 379         outmode[3] = 'f';
 380       else if (strcmp(*argv, "-h") == 0)
 381         outmode[3] = 'h';
 382       else if (strcmp(*argv, "-r") == 0)
 383         outmode[3] = 'R';
 384       else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' &&
 385                (*argv)[2] == 0)
 386         outmode[2] = (*argv)[1];
 387       else
 388         break;
 389       argc--, argv++;
 390     }
 391     if (outmode[3] == ' ')
 392         outmode[3] = 0;
 393     if (argc == 0) {
 394         SET_BINARY_MODE(stdin);
 395         SET_BINARY_MODE(stdout);
 396         if (uncompr) {
 397             file = gzdopen(fileno(stdin), "rb");
 398             if (file == NULL) error("can't gzdopen stdin");
 399             gz_uncompress(file, stdout);
 400         } else {
 401             file = gzdopen(fileno(stdout), outmode);
 402             if (file == NULL) error("can't gzdopen stdout");
 403             gz_compress(stdin, file);
 404         }
 405     } else {
 406         if (copyout) {
 407             SET_BINARY_MODE(stdout);
 408         }
 409         do {
 410             if (uncompr) {
 411                 if (copyout) {
 412                     file = gzopen(*argv, "rb");
 413                     if (file == NULL)
 414                         fprintf(stderr, "%s: can't gzopen %s\n", prog, *argv);
 415                     else
 416                         gz_uncompress(file, stdout);
 417                 } else {
 418                     file_uncompress(*argv);
 419                 }
 420             } else {
 421                 if (copyout) {
 422                     FILE * in = fopen(*argv, "rb");
 423
 424                     if (in == NULL) {
 425                         perror(*argv);
 426                     } else {
 427                         file = gzdopen(fileno(stdout), outmode);
 428                         if (file == NULL) error("can't gzdopen stdout");
 429
 430                         gz_compress(in, file);
 431                     }
 432
 433                 } else {
 434                     file_compress(*argv, outmode);
 435                 }
 436             }
 437         } while (argv++, --argc);
 438     }
 439     return 0;
 440 }