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(struct gzFile_s
));
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
);