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: minigzip.c,v 1.1.1.1 2011/06/10 09:34:40 andrew Exp $ */ 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} 323