1 /* minigzip.c -- simulate gzip using the zlib compression library
2 * Copyright (C) 1995-2006, 2010, 2011 Jean-loup Gailly.
3 * For conditions of distribution and use, see copyright notice in zlib.h
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
27 # include <sys/types.h>
28 # include <sys/mman.h>
29 # include <sys/stat.h>
32 #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
38 # define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
40 # define SET_BINARY_MODE(file)
44 # define unlink delete
45 # define GZ_SUFFIX "-gz"
48 # define unlink remove
49 # define GZ_SUFFIX "-gz"
50 # define fileno(file) file->__file
52 #if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
53 # include <unix.h> /* for fileno */
56 #if !defined(Z_HAVE_UNISTD_H) && !defined(_LARGEFILE64_SOURCE)
57 #ifndef WIN32 /* unlink already in stdio.h for WIN32 */
58 extern int unlink OF((const char *));
64 # define perror(s) pwinerror(s)
66 /* Map the Windows error number in ERROR to a locale-dependent error
67 message string and return a pointer to it. Typically, the values
68 for ERROR come from GetLastError.
70 The string pointed to shall not be modified by the application,
71 but may be overwritten by a subsequent call to strwinerror
73 The strwinerror function does not change the current setting
76 static char *strwinerror (error)
79 static char buf[1024];
82 DWORD lasterr = GetLastError();
83 DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
84 | FORMAT_MESSAGE_ALLOCATE_BUFFER,
87 0, /* Default language */
92 /* If there is an \r\n appended, zap it. */
94 && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
99 if (chars > sizeof (buf) - 1) {
100 chars = sizeof (buf) - 1;
104 wcstombs(buf, msgbuf, chars + 1);
108 sprintf(buf, "unknown win32 error (%ld)", error);
111 SetLastError(lasterr);
115 static void pwinerror (s)
119 fprintf(stderr, "%s: %s\n", s, strwinerror(GetLastError ()));
121 fprintf(stderr, "%s\n", strwinerror(GetLastError ()));
124 #endif /* UNDER_CE */
127 # define GZ_SUFFIX ".gz"
129 #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1)
132 #define MAX_NAME_LEN 1024
135 # define local static
136 /* Needed for systems with limitation on stack size. */
142 /* for Z_SOLO, create simplified gz* functions using deflate and inflate */
144 #if defined(Z_HAVE_UNISTD_H) || defined(Z_LARGE)
145 # include <unistd.h> /* for unlink() */
148 void *myalloc OF((void *, unsigned, unsigned));
149 void myfree OF((void *, void *));
151 void *myalloc(q, n, m)
166 typedef struct gzFile_s {
174 gzFile gzopen OF((const char *, const char *));
175 gzFile gzdopen OF((int, const char *));
176 gzFile gz_open OF((const char *, int, const char *));
178 gzFile gzopen(path, mode)
182 return gz_open(path, -1, mode);
185 gzFile gzdopen(fd, mode)
189 return gz_open(NULL, fd, mode);
192 gzFile gz_open(path, fd, mode)
200 gz = malloc(sizeof(gzFile));
203 gz->write = strchr(mode, 'w') != NULL;
204 gz->strm.zalloc = myalloc;
205 gz->strm.zfree = myfree;
206 gz->strm.opaque = Z_NULL;
208 ret = deflateInit2(&(gz->strm), -1, 8, 15 + 16, 8, 0);
210 gz->strm.next_in = 0;
211 gz->strm.avail_in = Z_NULL;
212 ret = inflateInit2(&(gz->strm), 15 + 16);
218 gz->file = path == NULL ? fdopen(fd, gz->write ? "wb" : "rb") :
219 fopen(path, gz->write ? "wb" : "rb");
220 if (gz->file == NULL) {
221 gz->write ? deflateEnd(&(gz->strm)) : inflateEnd(&(gz->strm));
230 int gzwrite OF((gzFile, const void *, unsigned));
232 int gzwrite(gz, buf, len)
238 unsigned char out[BUFLEN];
240 if (gz == NULL || !gz->write)
243 strm->next_in = (void *)buf;
244 strm->avail_in = len;
246 strm->next_out = out;
247 strm->avail_out = BUFLEN;
248 (void)deflate(strm, Z_NO_FLUSH);
249 fwrite(out, 1, BUFLEN - strm->avail_out, gz->file);
250 } while (strm->avail_out == 0);
254 int gzread OF((gzFile, void *, unsigned));
256 int gzread(gz, buf, len)
266 if (gz == NULL || gz->write)
271 strm->next_out = (void *)buf;
272 strm->avail_out = len;
274 got = fread(in, 1, 1, gz->file);
279 ret = inflate(strm, Z_NO_FLUSH);
280 if (ret == Z_DATA_ERROR) {
281 gz->err = Z_DATA_ERROR;
285 if (ret == Z_STREAM_END)
287 } while (strm->avail_out);
288 return len - strm->avail_out;
291 int gzclose OF((gzFile));
297 unsigned char out[BUFLEN];
300 return Z_STREAM_ERROR;
303 strm->next_in = Z_NULL;
306 strm->next_out = out;
307 strm->avail_out = BUFLEN;
308 (void)deflate(strm, Z_FINISH);
309 fwrite(out, 1, BUFLEN - strm->avail_out, gz->file);
310 } while (strm->avail_out == 0);
320 const char *gzerror OF((gzFile, int *));
322 const char *gzerror(gz, err)
334 void error OF((const char *msg));
335 void gz_compress OF((FILE *in, gzFile out));
337 int gz_compress_mmap OF((FILE *in, gzFile out));
339 void gz_uncompress OF((gzFile in, FILE *out));
340 void file_compress OF((char *file, char *mode));
341 void file_uncompress OF((char *file));
342 int main OF((int argc, char *argv[]));
344 /* ===========================================================================
345 * Display error message and exit
350 fprintf(stderr, "%s: %s\n", prog, msg);
354 /* ===========================================================================
355 * Compress input to output then close both files.
358 void gz_compress(in, out)
362 local char buf[BUFLEN];
367 /* Try first compressing with mmap. If mmap fails (minigzip used in a
368 * pipe), use the normal fread loop.
370 if (gz_compress_mmap(in, out) == Z_OK) return;
373 len = (int)fread(buf, 1, sizeof(buf), in);
380 if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err));
383 if (gzclose(out) != Z_OK) error("failed gzclose");
386 #ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */
388 /* Try compressing the input file at once using mmap. Return Z_OK if
389 * if success, Z_ERRNO otherwise.
391 int gz_compress_mmap(in, out)
397 int ifd = fileno(in);
398 caddr_t buf; /* mmap'ed buffer for the entire input file */
399 off_t buf_len; /* length of the input file */
402 /* Determine the size of the file, needed for mmap: */
403 if (fstat(ifd, &sb) < 0) return Z_ERRNO;
404 buf_len = sb.st_size;
405 if (buf_len <= 0) return Z_ERRNO;
407 /* Now do the actual mmap: */
408 buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0);
409 if (buf == (caddr_t)(-1)) return Z_ERRNO;
411 /* Compress the whole file at once: */
412 len = gzwrite(out, (char *)buf, (unsigned)buf_len);
414 if (len != (int)buf_len) error(gzerror(out, &err));
416 munmap(buf, buf_len);
418 if (gzclose(out) != Z_OK) error("failed gzclose");
421 #endif /* USE_MMAP */
423 /* ===========================================================================
424 * Uncompress input to output then close both files.
426 void gz_uncompress(in, out)
430 local char buf[BUFLEN];
435 len = gzread(in, buf, sizeof(buf));
436 if (len < 0) error (gzerror(in, &err));
439 if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
440 error("failed fwrite");
443 if (fclose(out)) error("failed fclose");
445 if (gzclose(in) != Z_OK) error("failed gzclose");
449 /* ===========================================================================
450 * Compress the given file: create a corresponding .gz file and remove the
453 void file_compress(file, mode)
457 local char outfile[MAX_NAME_LEN];
461 if (strlen(file) + strlen(GZ_SUFFIX) >= sizeof(outfile)) {
462 fprintf(stderr, "%s: filename too long\n", prog);
466 strcpy(outfile, file);
467 strcat(outfile, GZ_SUFFIX);
469 in = fopen(file, "rb");
474 out = gzopen(outfile, mode);
476 fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);
479 gz_compress(in, out);
485 /* ===========================================================================
486 * Uncompress the given file and remove the original.
488 void file_uncompress(file)
491 local char buf[MAX_NAME_LEN];
492 char *infile, *outfile;
495 size_t len = strlen(file);
497 if (len + strlen(GZ_SUFFIX) >= sizeof(buf)) {
498 fprintf(stderr, "%s: filename too long\n", prog);
504 if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {
507 outfile[len-3] = '\0';
511 strcat(infile, GZ_SUFFIX);
513 in = gzopen(infile, "rb");
515 fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);
518 out = fopen(outfile, "wb");
524 gz_uncompress(in, out);
530 /* ===========================================================================
531 * Usage: minigzip [-c] [-d] [-f] [-h] [-r] [-1 to -9] [files...]
532 * -c : write to standard output
534 * -f : compress with Z_FILTERED
535 * -h : compress with Z_HUFFMAN_ONLY
536 * -r : compress with Z_RLE
537 * -1 to -9 : compression level
547 char *bname, outmode[20];
549 strcpy(outmode, "wb6 ");
552 bname = strrchr(argv[0], '/');
559 if (!strcmp(bname, "gunzip"))
561 else if (!strcmp(bname, "zcat"))
562 copyout = uncompr = 1;
565 if (strcmp(*argv, "-c") == 0)
567 else if (strcmp(*argv, "-d") == 0)
569 else if (strcmp(*argv, "-f") == 0)
571 else if (strcmp(*argv, "-h") == 0)
573 else if (strcmp(*argv, "-r") == 0)
575 else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' &&
577 outmode[2] = (*argv)[1];
582 if (outmode[3] == ' ')
585 SET_BINARY_MODE(stdin);
586 SET_BINARY_MODE(stdout);
588 file = gzdopen(fileno(stdin), "rb");
589 if (file == NULL) error("can't gzdopen stdin");
590 gz_uncompress(file, stdout);
592 file = gzdopen(fileno(stdout), outmode);
593 if (file == NULL) error("can't gzdopen stdout");
594 gz_compress(stdin, file);
598 SET_BINARY_MODE(stdout);
603 file = gzopen(*argv, "rb");
605 fprintf(stderr, "%s: can't gzopen %s\n", prog, *argv);
607 gz_uncompress(file, stdout);
609 file_uncompress(*argv);
613 FILE * in = fopen(*argv, "rb");
618 file = gzdopen(fileno(stdout), outmode);
619 if (file == NULL) error("can't gzdopen stdout");
621 gz_compress(in, file);
625 file_compress(*argv, outmode);
628 } while (argv++, --argc);