minigzip.c Source File

00001 /* minigzip.c -- simulate gzip using the zlib compression library
00002  * Copyright (C) 1995-1998 Jean-loup Gailly.
00003  * For conditions of distribution and use, see copyright notice in zlib.h 
00004  */
00005 
00006 /*
00007  * minigzip is a minimal implementation of the gzip utility. This is
00008  * only an example of using zlib and isn't meant to replace the
00009  * full-featured gzip. No attempt is made to deal with file systems
00010  * limiting names to 14 or 8+3 characters, etc... Error checking is
00011  * very limited. So use minigzip only for testing; use gzip for the
00012  * real thing. On MSDOS, use only on file names without extension
00013  * or in pipe mode.
00014  */
00015 
00016 /* @(#) $Id$ */
00017 
00018 #include <stdio.h>
00019 #include <time.h>
00020 #include "zlib.h"
00021 
00022 #ifdef STDC
00023 #  include <string.h>
00024 #  include <stdlib.h>
00025 #else
00026    extern void exit  OF((int));
00027 #endif
00028 
00029 #ifdef USE_MMAP
00030 #  include <sys/types.h>
00031 #  include <sys/mman.h>
00032 #  include <sys/stat.h>
00033 #endif
00034 
00035 #if defined(MSDOS) || defined(OS2) || defined(WIN32)
00036 #  include <fcntl.h>
00037 #  include <io.h>
00038 #  define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
00039 #else
00040 #  define SET_BINARY_MODE(file)
00041 #endif
00042 
00043 #ifdef VMS
00044 #  define unlink delete
00045 #  define GZ_SUFFIX "-gz"
00046 #endif
00047 #ifdef RISCOS
00048 #  define unlink remove
00049 #  define GZ_SUFFIX "-gz"
00050 #  define fileno(file) file->__file
00051 #endif
00052 #if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
00053 #  include <unix.h> /* for fileno */
00054 #endif
00055 
00056 #ifndef WIN32 /* unlink already in stdio.h for WIN32 */
00057   extern int unlink OF((const char *));
00058 #endif
00059 
00060 #ifndef GZ_SUFFIX
00061 #  define GZ_SUFFIX ".gz"
00062 #endif
00063 #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1)
00064 
00065 #define BUFLEN      16384
00066 #define MAX_NAME_LEN 1024
00067 
00068 #ifdef MAXSEG_64K
00069 #  define local static
00070    /* Needed for systems with limitation on stack size. */
00071 #else
00072 #  define local
00073 #endif
00074 
00075 char *prog;
00076 
00077 void error            OF((const char *msg));
00078 void gz_compress      OF((FILE   *in, gzFile out));
00079 #ifdef USE_MMAP
00080 int  gz_compress_mmap OF((FILE   *in, gzFile out));
00081 #endif
00082 void gz_uncompress    OF((gzFile in, FILE   *out));
00083 void file_compress    OF((char  *file, char *mode));
00084 void file_uncompress  OF((char  *file));
00085 
00086 #ifdef WIN32
00087 int  __cdecl main     OF((int argc, char *argv[]));
00088 #else
00089 int  main     OF((int argc, char *argv[]));
00090 #endif
00091 
00092 char dotest=0;
00093 char use_stdout=0;
00094 
00095 /* ===========================================================================
00096  * Display error message and exit
00097  */
00098 void error(msg)
00099     const char *msg;
00100 {
00101     fprintf(stderr, "%s: %s\n", prog, msg);
00102     exit(1);
00103 }
00104 
00105 /* ===========================================================================
00106  * Compress input to output then close both files.
00107  */
00108 
00109 void gz_compress(in, out)
00110     FILE   *in;
00111     gzFile out;
00112 {
00113     local char buf[BUFLEN];
00114     int len;
00115     int err;
00116 
00117 #ifdef USE_MMAP
00118     /* Try first compressing with mmap. If mmap fails (minigzip used in a
00119      * pipe), use the normal fread loop.
00120      */
00121     if (gz_compress_mmap(in, out) == Z_OK) return;
00122 #endif
00123     for (;;) {
00124         len = fread(buf, 1, sizeof(buf), in);
00125         if (ferror(in)) {
00126             perror("fread");
00127             exit(1);
00128         }
00129         if (len == 0) break;
00130 
00131                   if(out!=NULL)
00132                         if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err));
00133     }
00134     fclose(in);
00135 
00136          if(out!=NULL)
00137                 if (gzclose(out) != Z_OK) error("failed gzclose");
00138 }
00139 
00140 #ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */
00141 
00142 /* Try compressing the input file at once using mmap. Return Z_OK if
00143  * if success, Z_ERRNO otherwise.
00144  */
00145 int gz_compress_mmap(in, out)
00146     FILE   *in;
00147     gzFile out;
00148 {
00149     int len;
00150     int err;
00151     int ifd = fileno(in);
00152     caddr_t buf;    /* mmap'ed buffer for the entire input file */
00153     off_t buf_len;  /* length of the input file */
00154     struct stat sb;
00155 
00156     /* Determine the size of the file, needed for mmap: */
00157     if (fstat(ifd, &sb) < 0) return Z_ERRNO;
00158     buf_len = sb.st_size;
00159     if (buf_len <= 0) return Z_ERRNO;
00160 
00161     /* Now do the actual mmap: */
00162     buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0); 
00163     if (buf == (caddr_t)(-1)) return Z_ERRNO;
00164 
00165     /* Compress the whole file at once: */
00166     len = gzwrite(out, (char *)buf, (unsigned)buf_len);
00167 
00168     if (len != (int)buf_len) error(gzerror(out, &err));
00169 
00170     munmap(buf, buf_len);
00171     fclose(in);
00172     if (gzclose(out) != Z_OK) error("failed gzclose");
00173     return Z_OK;
00174 }
00175 #endif /* USE_MMAP */
00176 
00177 /* ===========================================================================
00178  * Uncompress input to output then close both files.
00179  */
00180 void gz_uncompress(in, out)
00181     gzFile in;
00182     FILE   *out;
00183 {
00184     local char buf[BUFLEN];
00185     int len;
00186     int err;
00187 
00188     for (;;) {
00189         len = gzread(in, buf, sizeof(buf));
00190         if (len < 0) error (gzerror(in, &err));
00191         if (len == 0) break;
00192 
00193                   if(out!=NULL)
00194                   {
00195                           if(dotest==0)
00196                           {
00197                                   if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
00198                                  error("failed fwrite");
00199                                 }
00200                           }
00201                   }
00202     }
00203          if((out!=NULL)&&(out!=stdout))
00204                 if (fclose(out)) error("failed fclose");
00205 
00206                 gzclose(in);
00207 //    if (gzclose(in) != Z_OK) error("failed gzclose");
00208 }
00209 
00210 /* ===========================================================================
00211  * Compress the given file: create a corresponding .gz file and remove the
00212  * original.
00213  */
00214 void file_compress(file, mode)
00215     char  *file;
00216     char  *mode;
00217 {
00218     local char outfile[MAX_NAME_LEN];
00219     FILE  *in;
00220     gzFile out;
00221 
00222     strcpy(outfile, file);
00223     strcat(outfile, GZ_SUFFIX);
00224 
00225     in = fopen(file, "rb");
00226     if (in == NULL) {
00227         perror(file);
00228         exit(1);
00229     }
00230          if(use_stdout==0)
00231                  out = gzopen(outfile, mode);
00232          else
00233                  out = gzdopen(1, mode);
00234 
00235                  if (out == NULL) {
00236                           fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);
00237                           exit(1);
00238                  }
00239                  gz_compress(in, out);
00240 
00241 //               if(dotest==0)
00242 //                      unlink(file);
00243 }
00244 
00245 
00246 /* ===========================================================================
00247  * Uncompress the given file and remove the original.
00248  */
00249 
00250 void file_uncompress(file)
00251     char  *file;
00252 {
00253     local char buf[MAX_NAME_LEN];
00254     char *infile, *outfile;
00255     FILE  *out;
00256     gzFile in;
00257     int len = strlen(file);
00258 
00259     strcpy(buf, file);
00260 
00261     if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {
00262         infile = file;
00263         outfile = buf;
00264         outfile[len-3] = '\0';
00265     } else {
00266         outfile = file;
00267         infile = buf;
00268         strcat(infile, GZ_SUFFIX);
00269     }
00270     in = gzopen(infile, "rb");
00271     if (in == NULL) {
00272         fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);
00273         exit(1);
00274     }
00275          if(use_stdout==0)
00276          {
00277                  if(dotest==0)
00278                  {
00279                          out = fopen(outfile, "wb");
00280                          if (out == NULL) {
00281                                   perror(file);
00282                                   exit(1);
00283                          }
00284                  }
00285                  else
00286                          out=NULL;
00287 
00288             gz_uncompress(in, out);
00289 //               unlink(infile);
00290          }
00291          else
00292                  gz_uncompress(in, stdout);
00293 }
00294 
00295 
00296 /* ===========================================================================
00297  * Usage:  minigzip [-d] [-f] [-h] [-1 to -9] [files...]
00298  *   -d : decompress
00299  *   -f : compress with Z_FILTERED
00300  *   -h : compress with Z_HUFFMAN_ONLY
00301  *   -1 to -9 : compression level
00302  */
00303 
00304 #ifdef WIN32
00305 int __cdecl main(argc, argv)
00306 #else
00307 int main(argc, argv)
00308 #endif
00309     int argc;
00310     char *argv[];
00311 {
00312     int uncompr = 0;
00313     gzFile file;
00314     char outmode[20];
00315          clock_t c1,c2;
00316 
00317     strcpy(outmode, "wb6 ");
00318 
00319     prog = argv[0];
00320     argc--, argv++;
00321 
00322     while (argc > 0) {
00323       if (strcmp(*argv, "-t") == 0)
00324         dotest = 1;
00325           else
00326       if (strcmp(*argv, "-c") == 0)
00327         use_stdout = 1;
00328       else if (strcmp(*argv, "-d") == 0)
00329         uncompr = 1;
00330       else if (strcmp(*argv, "-f") == 0)
00331         outmode[3] = 'f';
00332       else if (strcmp(*argv, "-h") == 0)
00333         outmode[3] = 'h';
00334       else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' &&
00335                (*argv)[2] == 0)
00336         outmode[2] = (*argv)[1];
00337       else
00338         break;
00339       argc--, argv++;
00340     }
00341 
00342                 c1=clock();
00343 
00344     if (argc == 0) {
00345         SET_BINARY_MODE(stdin);
00346         SET_BINARY_MODE(stdout);
00347         if (uncompr) {
00348             file = gzdopen(fileno(stdin), "rb");
00349             if (file == NULL) error("can't gzdopen stdin");
00350             gz_uncompress(file, stdout);
00351         } else {
00352             file = gzdopen(fileno(stdout), outmode);
00353             if (file == NULL) error("can't gzdopen stdout");
00354             gz_compress(stdin, file);
00355         }
00356     } else {
00357         do {
00358             if (uncompr) {
00359                 file_uncompress(*argv);
00360             } else {
00361                 file_compress(*argv, outmode);
00362             }
00363         } while (argv++, --argc);
00364     }
00365 
00366          c2=clock();
00367 
00368          printf("Time: %f\n",((float)c2-(float)c1)/(float)CLOCKS_PER_SEC);
00369 
00370     exit(0);
00371     return 0; /* to avoid warning */
00372 }