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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 | ||
72 | char *prog; | |
73 | ||
74 | void error OF((const char *msg)); | |
75 | void gz_compress OF((FILE *in, gzFile out)); | |
76 | #ifdef USE_MMAP | |
77 | int gz_compress_mmap OF((FILE *in, gzFile out)); | |
78 | #endif | |
79 | void gz_uncompress OF((gzFile in, FILE *out)); | |
80 | void file_compress OF((char *file, char *mode)); | |
81 | void file_uncompress OF((char *file)); | |
82 | int main OF((int argc, char *argv[])); | |
83 | ||
84 | /* =========================================================================== | |
85 | * Display error message and exit | |
86 | */ | |
87 | void 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 | ||
98 | void 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 | */ | |
131 | int 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 | */ | |
166 | void 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 | */ | |
193 | void 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 | */ | |
223 | void 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 | ||
269 | int 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 | } |