| 1 | /* minigzip.c -- simulate gzip using the zlib compression library |
| 2 | * Copyright (C) 1995-1998 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/zlib.h" |
| 20 | |
| 21 | #ifdef STDC |
| 22 | # include <string.h> |
| 23 | # include <stdlib.h> |
| 24 | #else |
| 25 | extern void exit OF((int)); |
| 26 | #endif |
| 27 | |
| 28 | #ifdef USE_MMAP |
| 29 | # include <sys/types.h> |
| 30 | # include <sys/mman.h> |
| 31 | # include <sys/stat.h> |
| 32 | #endif |
| 33 | |
| 34 | #if defined(MSDOS) || defined(OS2) || defined(WIN32) |
| 35 | # include <fcntl.h> |
| 36 | # include <io.h> |
| 37 | # define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) |
| 38 | #else |
| 39 | # define SET_BINARY_MODE(file) |
| 40 | #endif |
| 41 | |
| 42 | #ifdef VMS |
| 43 | # define unlink delete |
| 44 | # define GZ_SUFFIX "-gz" |
| 45 | #endif |
| 46 | #ifdef RISCOS |
| 47 | # define unlink remove |
| 48 | # define GZ_SUFFIX "-gz" |
| 49 | # define fileno(file) file->__file |
| 50 | #endif |
| 51 | |
| 52 | #ifndef WIN32 /* unlink already in stdio.h for WIN32 */ |
| 53 | extern int unlink OF((const char *)); |
| 54 | #endif |
| 55 | |
| 56 | #ifndef GZ_SUFFIX |
| 57 | # define GZ_SUFFIX ".gz" |
| 58 | #endif |
| 59 | #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1) |
| 60 | |
| 61 | #define BUFLEN 16384 |
| 62 | #define MAX_NAME_LEN 1024 |
| 63 | |
| 64 | #ifdef MAXSEG_64K |
| 65 | # define local static |
| 66 | /* Needed for systems with limitation on stack size. */ |
| 67 | #else |
| 68 | # define local |
| 69 | #endif |
| 70 | |
| 71 | char *prog; |
| 72 | |
| 73 | void error OF((const char *msg)); |
| 74 | void gz_compress OF((FILE *in, gzFile out)); |
| 75 | #ifdef USE_MMAP |
| 76 | int gz_compress_mmap OF((FILE *in, gzFile out)); |
| 77 | #endif |
| 78 | void gz_uncompress OF((gzFile in, FILE *out)); |
| 79 | void file_compress OF((char *file, char *mode)); |
| 80 | void file_uncompress OF((char *file)); |
| 81 | int main OF((int argc, char *argv[])); |
| 82 | |
| 83 | /* =========================================================================== |
| 84 | * Display error message and exit |
| 85 | */ |
| 86 | void error(msg) |
| 87 | const char *msg; |
| 88 | { |
| 89 | fprintf(stderr, "%s: %s\n", prog, msg); |
| 90 | exit(1); |
| 91 | } |
| 92 | |
| 93 | /* =========================================================================== |
| 94 | * Compress input to output then close both files. |
| 95 | */ |
| 96 | |
| 97 | void gz_compress(in, out) |
| 98 | FILE *in; |
| 99 | gzFile out; |
| 100 | { |
| 101 | local char buf[BUFLEN]; |
| 102 | int len; |
| 103 | int err; |
| 104 | |
| 105 | #ifdef USE_MMAP |
| 106 | /* Try first compressing with mmap. If mmap fails (minigzip used in a |
| 107 | * pipe), use the normal fread loop. |
| 108 | */ |
| 109 | if (gz_compress_mmap(in, out) == Z_OK) return; |
| 110 | #endif |
| 111 | for (;;) { |
| 112 | len = fread(buf, 1, sizeof(buf), in); |
| 113 | if (ferror(in)) { |
| 114 | perror("fread"); |
| 115 | exit(1); |
| 116 | } |
| 117 | if (len == 0) break; |
| 118 | |
| 119 | if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err)); |
| 120 | } |
| 121 | fclose(in); |
| 122 | if (gzclose(out) != Z_OK) error("failed gzclose"); |
| 123 | } |
| 124 | |
| 125 | #ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */ |
| 126 | |
| 127 | /* Try compressing the input file at once using mmap. Return Z_OK if |
| 128 | * if success, Z_ERRNO otherwise. |
| 129 | */ |
| 130 | int gz_compress_mmap(in, out) |
| 131 | FILE *in; |
| 132 | gzFile out; |
| 133 | { |
| 134 | int len; |
| 135 | int err; |
| 136 | int ifd = fileno(in); |
| 137 | caddr_t buf; /* mmap'ed buffer for the entire input file */ |
| 138 | off_t buf_len; /* length of the input file */ |
| 139 | struct stat sb; |
| 140 | |
| 141 | /* Determine the size of the file, needed for mmap: */ |
| 142 | if (fstat(ifd, &sb) < 0) return Z_ERRNO; |
| 143 | buf_len = sb.st_size; |
| 144 | if (buf_len <= 0) return Z_ERRNO; |
| 145 | |
| 146 | /* Now do the actual mmap: */ |
| 147 | buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0); |
| 148 | if (buf == (caddr_t)(-1)) return Z_ERRNO; |
| 149 | |
| 150 | /* Compress the whole file at once: */ |
| 151 | len = gzwrite(out, (char *)buf, (unsigned)buf_len); |
| 152 | |
| 153 | if (len != (int)buf_len) error(gzerror(out, &err)); |
| 154 | |
| 155 | munmap(buf, buf_len); |
| 156 | fclose(in); |
| 157 | if (gzclose(out) != Z_OK) error("failed gzclose"); |
| 158 | return Z_OK; |
| 159 | } |
| 160 | #endif /* USE_MMAP */ |
| 161 | |
| 162 | /* =========================================================================== |
| 163 | * Uncompress input to output then close both files. |
| 164 | */ |
| 165 | void gz_uncompress(in, out) |
| 166 | gzFile in; |
| 167 | FILE *out; |
| 168 | { |
| 169 | local char buf[BUFLEN]; |
| 170 | int len; |
| 171 | int err; |
| 172 | |
| 173 | for (;;) { |
| 174 | len = gzread(in, buf, sizeof(buf)); |
| 175 | if (len < 0) error (gzerror(in, &err)); |
| 176 | if (len == 0) break; |
| 177 | |
| 178 | if ((int)fwrite(buf, 1, (unsigned)len, out) != len) { |
| 179 | error("failed fwrite"); |
| 180 | } |
| 181 | } |
| 182 | if (fclose(out)) error("failed fclose"); |
| 183 | |
| 184 | if (gzclose(in) != Z_OK) error("failed gzclose"); |
| 185 | } |
| 186 | |
| 187 | |
| 188 | /* =========================================================================== |
| 189 | * Compress the given file: create a corresponding .gz file and remove the |
| 190 | * original. |
| 191 | */ |
| 192 | void file_compress(file, mode) |
| 193 | char *file; |
| 194 | char *mode; |
| 195 | { |
| 196 | local char outfile[MAX_NAME_LEN]; |
| 197 | FILE *in; |
| 198 | gzFile out; |
| 199 | |
| 200 | strcpy(outfile, file); |
| 201 | strcat(outfile, GZ_SUFFIX); |
| 202 | |
| 203 | in = fopen(file, "rb"); |
| 204 | if (in == NULL) { |
| 205 | perror(file); |
| 206 | exit(1); |
| 207 | } |
| 208 | out = gzopen(outfile, mode); |
| 209 | if (out == NULL) { |
| 210 | fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile); |
| 211 | exit(1); |
| 212 | } |
| 213 | gz_compress(in, out); |
| 214 | |
| 215 | unlink(file); |
| 216 | } |
| 217 | |
| 218 | |
| 219 | /* =========================================================================== |
| 220 | * Uncompress the given file and remove the original. |
| 221 | */ |
| 222 | void file_uncompress(file) |
| 223 | char *file; |
| 224 | { |
| 225 | local char buf[MAX_NAME_LEN]; |
| 226 | char *infile, *outfile; |
| 227 | FILE *out; |
| 228 | gzFile in; |
| 229 | int len = strlen(file); |
| 230 | |
| 231 | strcpy(buf, file); |
| 232 | |
| 233 | if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) { |
| 234 | infile = file; |
| 235 | outfile = buf; |
| 236 | outfile[len-3] = '\0'; |
| 237 | } else { |
| 238 | outfile = file; |
| 239 | infile = buf; |
| 240 | strcat(infile, GZ_SUFFIX); |
| 241 | } |
| 242 | in = gzopen(infile, "rb"); |
| 243 | if (in == NULL) { |
| 244 | fprintf(stderr, "%s: can't gzopen %s\n", prog, infile); |
| 245 | exit(1); |
| 246 | } |
| 247 | out = fopen(outfile, "wb"); |
| 248 | if (out == NULL) { |
| 249 | perror(file); |
| 250 | exit(1); |
| 251 | } |
| 252 | |
| 253 | gz_uncompress(in, out); |
| 254 | |
| 255 | unlink(infile); |
| 256 | } |
| 257 | |
| 258 | |
| 259 | /* =========================================================================== |
| 260 | * Usage: minigzip [-d] [-f] [-h] [-1 to -9] [files...] |
| 261 | * -d : decompress |
| 262 | * -f : compress with Z_FILTERED |
| 263 | * -h : compress with Z_HUFFMAN_ONLY |
| 264 | * -1 to -9 : compression level |
| 265 | */ |
| 266 | |
| 267 | int main(argc, argv) |
| 268 | int argc; |
| 269 | char *argv[]; |
| 270 | { |
| 271 | int uncompr = 0; |
| 272 | gzFile file; |
| 273 | char outmode[20]; |
| 274 | |
| 275 | strcpy(outmode, "wb6 "); |
| 276 | |
| 277 | prog = argv[0]; |
| 278 | argc--, argv++; |
| 279 | |
| 280 | while (argc > 0) { |
| 281 | if (strcmp(*argv, "-d") == 0) |
| 282 | uncompr = 1; |
| 283 | else if (strcmp(*argv, "-f") == 0) |
| 284 | outmode[3] = 'f'; |
| 285 | else if (strcmp(*argv, "-h") == 0) |
| 286 | outmode[3] = 'h'; |
| 287 | else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' && |
| 288 | (*argv)[2] == 0) |
| 289 | outmode[2] = (*argv)[1]; |
| 290 | else |
| 291 | break; |
| 292 | argc--, argv++; |
| 293 | } |
| 294 | if (argc == 0) { |
| 295 | SET_BINARY_MODE(stdin); |
| 296 | SET_BINARY_MODE(stdout); |
| 297 | if (uncompr) { |
| 298 | file = gzdopen(fileno(stdin), "rb"); |
| 299 | if (file == NULL) error("can't gzdopen stdin"); |
| 300 | gz_uncompress(file, stdout); |
| 301 | } else { |
| 302 | file = gzdopen(fileno(stdout), outmode); |
| 303 | if (file == NULL) error("can't gzdopen stdout"); |
| 304 | gz_compress(stdin, file); |
| 305 | } |
| 306 | } else { |
| 307 | do { |
| 308 | if (uncompr) { |
| 309 | file_uncompress(*argv); |
| 310 | } else { |
| 311 | file_compress(*argv, outmode); |
| 312 | } |
| 313 | } while (argv++, --argc); |
| 314 | } |
| 315 | exit(0); |
| 316 | return 0; /* to avoid warning */ |
| 317 | } |