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1 | /* minigzip.c -- simulate gzip using the zlib compression library | |
2 | * Copyright (C) 1995-2002 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 | #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) || defined(__CYGWIN__) | |
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 | #if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os | |
52 | # include <unix.h> /* for fileno */ | |
53 | #endif | |
54 | ||
55 | #ifndef WIN32 /* unlink already in stdio.h for WIN32 */ | |
56 | extern int unlink OF((const char *)); | |
57 | #endif | |
58 | ||
59 | #ifndef GZ_SUFFIX | |
60 | # define GZ_SUFFIX ".gz" | |
61 | #endif | |
62 | #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1) | |
63 | ||
64 | #define BUFLEN 16384 | |
65 | #define MAX_NAME_LEN 1024 | |
66 | ||
67 | #ifdef MAXSEG_64K | |
68 | # define local static | |
69 | /* Needed for systems with limitation on stack size. */ | |
70 | #else | |
71 | # define local | |
72 | #endif | |
73 | ||
74 | char *prog; | |
75 | ||
76 | void error OF((const char *msg)); | |
77 | void gz_compress OF((FILE *in, gzFile out)); | |
78 | #ifdef USE_MMAP | |
79 | int gz_compress_mmap OF((FILE *in, gzFile out)); | |
80 | #endif | |
81 | void gz_uncompress OF((gzFile in, FILE *out)); | |
82 | void file_compress OF((char *file, char *mode)); | |
83 | void file_uncompress OF((char *file)); | |
84 | int main OF((int argc, char *argv[])); | |
85 | ||
86 | /* =========================================================================== | |
87 | * Display error message and exit | |
88 | */ | |
89 | void error(msg) | |
90 | const char *msg; | |
91 | { | |
92 | fprintf(stderr, "%s: %s\n", prog, msg); | |
93 | exit(1); | |
94 | } | |
95 | ||
96 | /* =========================================================================== | |
97 | * Compress input to output then close both files. | |
98 | */ | |
99 | ||
100 | void gz_compress(in, out) | |
101 | FILE *in; | |
102 | gzFile out; | |
103 | { | |
104 | local char buf[BUFLEN]; | |
105 | int len; | |
106 | int err; | |
107 | ||
108 | #ifdef USE_MMAP | |
109 | /* Try first compressing with mmap. If mmap fails (minigzip used in a | |
110 | * pipe), use the normal fread loop. | |
111 | */ | |
112 | if (gz_compress_mmap(in, out) == Z_OK) return; | |
113 | #endif | |
114 | for (;;) { | |
115 | len = (int)fread(buf, 1, sizeof(buf), in); | |
116 | if (ferror(in)) { | |
117 | perror("fread"); | |
118 | exit(1); | |
119 | } | |
120 | if (len == 0) break; | |
121 | ||
122 | if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err)); | |
123 | } | |
124 | fclose(in); | |
125 | if (gzclose(out) != Z_OK) error("failed gzclose"); | |
126 | } | |
127 | ||
128 | #ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */ | |
129 | ||
130 | /* Try compressing the input file at once using mmap. Return Z_OK if | |
131 | * if success, Z_ERRNO otherwise. | |
132 | */ | |
133 | int gz_compress_mmap(in, out) | |
134 | FILE *in; | |
135 | gzFile out; | |
136 | { | |
137 | int len; | |
138 | int err; | |
139 | int ifd = fileno(in); | |
140 | caddr_t buf; /* mmap'ed buffer for the entire input file */ | |
141 | off_t buf_len; /* length of the input file */ | |
142 | struct stat sb; | |
143 | ||
144 | /* Determine the size of the file, needed for mmap: */ | |
145 | if (fstat(ifd, &sb) < 0) return Z_ERRNO; | |
146 | buf_len = sb.st_size; | |
147 | if (buf_len <= 0) return Z_ERRNO; | |
148 | ||
149 | /* Now do the actual mmap: */ | |
150 | buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0); | |
151 | if (buf == (caddr_t)(-1)) return Z_ERRNO; | |
152 | ||
153 | /* Compress the whole file at once: */ | |
154 | len = gzwrite(out, (char *)buf, (unsigned)buf_len); | |
155 | ||
156 | if (len != (int)buf_len) error(gzerror(out, &err)); | |
157 | ||
158 | munmap(buf, buf_len); | |
159 | fclose(in); | |
160 | if (gzclose(out) != Z_OK) error("failed gzclose"); | |
161 | return Z_OK; | |
162 | } | |
163 | #endif /* USE_MMAP */ | |
164 | ||
165 | /* =========================================================================== | |
166 | * Uncompress input to output then close both files. | |
167 | */ | |
168 | void gz_uncompress(in, out) | |
169 | gzFile in; | |
170 | FILE *out; | |
171 | { | |
172 | local char buf[BUFLEN]; | |
173 | int len; | |
174 | int err; | |
175 | ||
176 | for (;;) { | |
177 | len = gzread(in, buf, sizeof(buf)); | |
178 | if (len < 0) error (gzerror(in, &err)); | |
179 | if (len == 0) break; | |
180 | ||
181 | if ((int)fwrite(buf, 1, (unsigned)len, out) != len) { | |
182 | error("failed fwrite"); | |
183 | } | |
184 | } | |
185 | if (fclose(out)) error("failed fclose"); | |
186 | ||
187 | if (gzclose(in) != Z_OK) error("failed gzclose"); | |
188 | } | |
189 | ||
190 | ||
191 | /* =========================================================================== | |
192 | * Compress the given file: create a corresponding .gz file and remove the | |
193 | * original. | |
194 | */ | |
195 | void file_compress(file, mode) | |
196 | char *file; | |
197 | char *mode; | |
198 | { | |
199 | local char outfile[MAX_NAME_LEN]; | |
200 | FILE *in; | |
201 | gzFile out; | |
202 | ||
203 | strcpy(outfile, file); | |
204 | strcat(outfile, GZ_SUFFIX); | |
205 | ||
206 | in = fopen(file, "rb"); | |
207 | if (in == NULL) { | |
208 | perror(file); | |
209 | exit(1); | |
210 | } | |
211 | out = gzopen(outfile, mode); | |
212 | if (out == NULL) { | |
213 | fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile); | |
214 | exit(1); | |
215 | } | |
216 | gz_compress(in, out); | |
217 | ||
218 | unlink(file); | |
219 | } | |
220 | ||
221 | ||
222 | /* =========================================================================== | |
223 | * Uncompress the given file and remove the original. | |
224 | */ | |
225 | void file_uncompress(file) | |
226 | char *file; | |
227 | { | |
228 | local char buf[MAX_NAME_LEN]; | |
229 | char *infile, *outfile; | |
230 | FILE *out; | |
231 | gzFile in; | |
232 | uInt len = (uInt)strlen(file); | |
233 | ||
234 | strcpy(buf, file); | |
235 | ||
236 | if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) { | |
237 | infile = file; | |
238 | outfile = buf; | |
239 | outfile[len-3] = '\0'; | |
240 | } else { | |
241 | outfile = file; | |
242 | infile = buf; | |
243 | strcat(infile, GZ_SUFFIX); | |
244 | } | |
245 | in = gzopen(infile, "rb"); | |
246 | if (in == NULL) { | |
247 | fprintf(stderr, "%s: can't gzopen %s\n", prog, infile); | |
248 | exit(1); | |
249 | } | |
250 | out = fopen(outfile, "wb"); | |
251 | if (out == NULL) { | |
252 | perror(file); | |
253 | exit(1); | |
254 | } | |
255 | ||
256 | gz_uncompress(in, out); | |
257 | ||
258 | unlink(infile); | |
259 | } | |
260 | ||
261 | ||
262 | /* =========================================================================== | |
263 | * Usage: minigzip [-d] [-f] [-h] [-r] [-1 to -9] [files...] | |
264 | * -d : decompress | |
265 | * -f : compress with Z_FILTERED | |
266 | * -h : compress with Z_HUFFMAN_ONLY | |
267 | * -r : compress with Z_RLE | |
268 | * -1 to -9 : compression level | |
269 | */ | |
270 | ||
271 | int main(argc, argv) | |
272 | int argc; | |
273 | char *argv[]; | |
274 | { | |
275 | int uncompr = 0; | |
276 | gzFile file; | |
277 | char outmode[20]; | |
278 | ||
279 | strcpy(outmode, "wb6 "); | |
280 | ||
281 | prog = argv[0]; | |
282 | argc--, argv++; | |
283 | ||
284 | while (argc > 0) { | |
285 | if (strcmp(*argv, "-d") == 0) | |
286 | uncompr = 1; | |
287 | else if (strcmp(*argv, "-f") == 0) | |
288 | outmode[3] = 'f'; | |
289 | else if (strcmp(*argv, "-h") == 0) | |
290 | outmode[3] = 'h'; | |
291 | else if (strcmp(*argv, "-r") == 0) | |
292 | outmode[3] = 'R'; | |
293 | else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' && | |
294 | (*argv)[2] == 0) | |
295 | outmode[2] = (*argv)[1]; | |
296 | else | |
297 | break; | |
298 | argc--, argv++; | |
299 | } | |
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 | } |