Move example.c and minigzip.c to examples/ directory.

This commit is contained in:
Mark Adler
2011-10-09 09:50:48 -07:00
parent 77b47d55f1
commit 1bd2fa1b24
5 changed files with 22 additions and 9 deletions

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@@ -6,6 +6,10 @@ enough.c
- calculates the maximum table space used in inflate tree
construction over all possible Huffman codes
example.c
usage examples of zlib
- used in zlib build Makefile for testing
fitblk.c
compress just enough input to nearly fill a requested output size
- zlib isn't designed to do this, but fitblk does it anyway
@@ -34,6 +38,11 @@ gzlog.h
and deflateSetDictionary()
- illustrates use of a gzip header extra field
minigzip.c
minimal implementation of gzip-like functionality using zlib
- used in zlib build Makefile for testing
- is not meant for and should not be used as a gzip replacement
zlib_how.html
painfully comprehensive description of zpipe.c (see below)
- describes in excruciating detail the use of deflate() and inflate()

601
examples/example.c Normal file
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@@ -0,0 +1,601 @@
/* example.c -- usage example of the zlib compression library
* Copyright (C) 1995-2006, 2011 Jean-loup Gailly.
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/* @(#) $Id$ */
#include "zlib.h"
#include <stdio.h>
#ifdef STDC
# include <string.h>
# include <stdlib.h>
#endif
#if defined(VMS) || defined(RISCOS)
# define TESTFILE "foo-gz"
#else
# define TESTFILE "foo.gz"
#endif
#define CHECK_ERR(err, msg) { \
if (err != Z_OK) { \
fprintf(stderr, "%s error: %d\n", msg, err); \
exit(1); \
} \
}
const char hello[] = "hello, hello!";
/* "hello world" would be more standard, but the repeated "hello"
* stresses the compression code better, sorry...
*/
const char dictionary[] = "hello";
uLong dictId; /* Adler32 value of the dictionary */
void test_deflate OF((Byte *compr, uLong comprLen));
void test_inflate OF((Byte *compr, uLong comprLen,
Byte *uncompr, uLong uncomprLen));
void test_large_deflate OF((Byte *compr, uLong comprLen,
Byte *uncompr, uLong uncomprLen));
void test_large_inflate OF((Byte *compr, uLong comprLen,
Byte *uncompr, uLong uncomprLen));
void test_flush OF((Byte *compr, uLong *comprLen));
void test_sync OF((Byte *compr, uLong comprLen,
Byte *uncompr, uLong uncomprLen));
void test_dict_deflate OF((Byte *compr, uLong comprLen));
void test_dict_inflate OF((Byte *compr, uLong comprLen,
Byte *uncompr, uLong uncomprLen));
int main OF((int argc, char *argv[]));
#ifdef Z_SOLO
void *myalloc OF((void *, unsigned, unsigned));
void myfree OF((void *, void *));
void *myalloc(q, n, m)
void *q;
unsigned n, m;
{
q = Z_NULL;
return calloc(n, m);
}
void myfree(void *q, void *p)
{
q = Z_NULL;
free(p);
}
static alloc_func zalloc = myalloc;
static free_func zfree = myfree;
#else /* !Z_SOLO */
static alloc_func zalloc = (alloc_func)0;
static free_func zfree = (free_func)0;
void test_compress OF((Byte *compr, uLong comprLen,
Byte *uncompr, uLong uncomprLen));
void test_gzio OF((const char *fname,
Byte *uncompr, uLong uncomprLen));
/* ===========================================================================
* Test compress() and uncompress()
*/
void test_compress(compr, comprLen, uncompr, uncomprLen)
Byte *compr, *uncompr;
uLong comprLen, uncomprLen;
{
int err;
uLong len = (uLong)strlen(hello)+1;
err = compress(compr, &comprLen, (const Bytef*)hello, len);
CHECK_ERR(err, "compress");
strcpy((char*)uncompr, "garbage");
err = uncompress(uncompr, &uncomprLen, compr, comprLen);
CHECK_ERR(err, "uncompress");
if (strcmp((char*)uncompr, hello)) {
fprintf(stderr, "bad uncompress\n");
exit(1);
} else {
printf("uncompress(): %s\n", (char *)uncompr);
}
}
/* ===========================================================================
* Test read/write of .gz files
*/
void test_gzio(fname, uncompr, uncomprLen)
const char *fname; /* compressed file name */
Byte *uncompr;
uLong uncomprLen;
{
#ifdef NO_GZCOMPRESS
fprintf(stderr, "NO_GZCOMPRESS -- gz* functions cannot compress\n");
#else
int err;
int len = (int)strlen(hello)+1;
gzFile file;
z_off_t pos;
file = gzopen(fname, "wb");
if (file == NULL) {
fprintf(stderr, "gzopen error\n");
exit(1);
}
gzputc(file, 'h');
if (gzputs(file, "ello") != 4) {
fprintf(stderr, "gzputs err: %s\n", gzerror(file, &err));
exit(1);
}
if (gzprintf(file, ", %s!", "hello") != 8) {
fprintf(stderr, "gzprintf err: %s\n", gzerror(file, &err));
exit(1);
}
gzseek(file, 1L, SEEK_CUR); /* add one zero byte */
gzclose(file);
file = gzopen(fname, "rb");
if (file == NULL) {
fprintf(stderr, "gzopen error\n");
exit(1);
}
strcpy((char*)uncompr, "garbage");
if (gzread(file, uncompr, (unsigned)uncomprLen) != len) {
fprintf(stderr, "gzread err: %s\n", gzerror(file, &err));
exit(1);
}
if (strcmp((char*)uncompr, hello)) {
fprintf(stderr, "bad gzread: %s\n", (char*)uncompr);
exit(1);
} else {
printf("gzread(): %s\n", (char*)uncompr);
}
pos = gzseek(file, -8L, SEEK_CUR);
if (pos != 6 || gztell(file) != pos) {
fprintf(stderr, "gzseek error, pos=%ld, gztell=%ld\n",
(long)pos, (long)gztell(file));
exit(1);
}
if (gzgetc(file) != ' ') {
fprintf(stderr, "gzgetc error\n");
exit(1);
}
if (gzungetc(' ', file) != ' ') {
fprintf(stderr, "gzungetc error\n");
exit(1);
}
gzgets(file, (char*)uncompr, (int)uncomprLen);
if (strlen((char*)uncompr) != 7) { /* " hello!" */
fprintf(stderr, "gzgets err after gzseek: %s\n", gzerror(file, &err));
exit(1);
}
if (strcmp((char*)uncompr, hello + 6)) {
fprintf(stderr, "bad gzgets after gzseek\n");
exit(1);
} else {
printf("gzgets() after gzseek: %s\n", (char*)uncompr);
}
gzclose(file);
#endif
}
#endif /* Z_SOLO */
/* ===========================================================================
* Test deflate() with small buffers
*/
void test_deflate(compr, comprLen)
Byte *compr;
uLong comprLen;
{
z_stream c_stream; /* compression stream */
int err;
uLong len = (uLong)strlen(hello)+1;
c_stream.zalloc = zalloc;
c_stream.zfree = zfree;
c_stream.opaque = (voidpf)0;
err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
CHECK_ERR(err, "deflateInit");
c_stream.next_in = (Bytef*)hello;
c_stream.next_out = compr;
while (c_stream.total_in != len && c_stream.total_out < comprLen) {
c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */
err = deflate(&c_stream, Z_NO_FLUSH);
CHECK_ERR(err, "deflate");
}
/* Finish the stream, still forcing small buffers: */
for (;;) {
c_stream.avail_out = 1;
err = deflate(&c_stream, Z_FINISH);
if (err == Z_STREAM_END) break;
CHECK_ERR(err, "deflate");
}
err = deflateEnd(&c_stream);
CHECK_ERR(err, "deflateEnd");
}
/* ===========================================================================
* Test inflate() with small buffers
*/
void test_inflate(compr, comprLen, uncompr, uncomprLen)
Byte *compr, *uncompr;
uLong comprLen, uncomprLen;
{
int err;
z_stream d_stream; /* decompression stream */
strcpy((char*)uncompr, "garbage");
d_stream.zalloc = zalloc;
d_stream.zfree = zfree;
d_stream.opaque = (voidpf)0;
d_stream.next_in = compr;
d_stream.avail_in = 0;
d_stream.next_out = uncompr;
err = inflateInit(&d_stream);
CHECK_ERR(err, "inflateInit");
while (d_stream.total_out < uncomprLen && d_stream.total_in < comprLen) {
d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */
err = inflate(&d_stream, Z_NO_FLUSH);
if (err == Z_STREAM_END) break;
CHECK_ERR(err, "inflate");
}
err = inflateEnd(&d_stream);
CHECK_ERR(err, "inflateEnd");
if (strcmp((char*)uncompr, hello)) {
fprintf(stderr, "bad inflate\n");
exit(1);
} else {
printf("inflate(): %s\n", (char *)uncompr);
}
}
/* ===========================================================================
* Test deflate() with large buffers and dynamic change of compression level
*/
void test_large_deflate(compr, comprLen, uncompr, uncomprLen)
Byte *compr, *uncompr;
uLong comprLen, uncomprLen;
{
z_stream c_stream; /* compression stream */
int err;
c_stream.zalloc = zalloc;
c_stream.zfree = zfree;
c_stream.opaque = (voidpf)0;
err = deflateInit(&c_stream, Z_BEST_SPEED);
CHECK_ERR(err, "deflateInit");
c_stream.next_out = compr;
c_stream.avail_out = (uInt)comprLen;
/* At this point, uncompr is still mostly zeroes, so it should compress
* very well:
*/
c_stream.next_in = uncompr;
c_stream.avail_in = (uInt)uncomprLen;
err = deflate(&c_stream, Z_NO_FLUSH);
CHECK_ERR(err, "deflate");
if (c_stream.avail_in != 0) {
fprintf(stderr, "deflate not greedy\n");
exit(1);
}
/* Feed in already compressed data and switch to no compression: */
deflateParams(&c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY);
c_stream.next_in = compr;
c_stream.avail_in = (uInt)comprLen/2;
err = deflate(&c_stream, Z_NO_FLUSH);
CHECK_ERR(err, "deflate");
/* Switch back to compressing mode: */
deflateParams(&c_stream, Z_BEST_COMPRESSION, Z_FILTERED);
c_stream.next_in = uncompr;
c_stream.avail_in = (uInt)uncomprLen;
err = deflate(&c_stream, Z_NO_FLUSH);
CHECK_ERR(err, "deflate");
err = deflate(&c_stream, Z_FINISH);
if (err != Z_STREAM_END) {
fprintf(stderr, "deflate should report Z_STREAM_END\n");
exit(1);
}
err = deflateEnd(&c_stream);
CHECK_ERR(err, "deflateEnd");
}
/* ===========================================================================
* Test inflate() with large buffers
*/
void test_large_inflate(compr, comprLen, uncompr, uncomprLen)
Byte *compr, *uncompr;
uLong comprLen, uncomprLen;
{
int err;
z_stream d_stream; /* decompression stream */
strcpy((char*)uncompr, "garbage");
d_stream.zalloc = zalloc;
d_stream.zfree = zfree;
d_stream.opaque = (voidpf)0;
d_stream.next_in = compr;
d_stream.avail_in = (uInt)comprLen;
err = inflateInit(&d_stream);
CHECK_ERR(err, "inflateInit");
for (;;) {
d_stream.next_out = uncompr; /* discard the output */
d_stream.avail_out = (uInt)uncomprLen;
err = inflate(&d_stream, Z_NO_FLUSH);
if (err == Z_STREAM_END) break;
CHECK_ERR(err, "large inflate");
}
err = inflateEnd(&d_stream);
CHECK_ERR(err, "inflateEnd");
if (d_stream.total_out != 2*uncomprLen + comprLen/2) {
fprintf(stderr, "bad large inflate: %ld\n", d_stream.total_out);
exit(1);
} else {
printf("large_inflate(): OK\n");
}
}
/* ===========================================================================
* Test deflate() with full flush
*/
void test_flush(compr, comprLen)
Byte *compr;
uLong *comprLen;
{
z_stream c_stream; /* compression stream */
int err;
uInt len = (uInt)strlen(hello)+1;
c_stream.zalloc = zalloc;
c_stream.zfree = zfree;
c_stream.opaque = (voidpf)0;
err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION);
CHECK_ERR(err, "deflateInit");
c_stream.next_in = (Bytef*)hello;
c_stream.next_out = compr;
c_stream.avail_in = 3;
c_stream.avail_out = (uInt)*comprLen;
err = deflate(&c_stream, Z_FULL_FLUSH);
CHECK_ERR(err, "deflate");
compr[3]++; /* force an error in first compressed block */
c_stream.avail_in = len - 3;
err = deflate(&c_stream, Z_FINISH);
if (err != Z_STREAM_END) {
CHECK_ERR(err, "deflate");
}
err = deflateEnd(&c_stream);
CHECK_ERR(err, "deflateEnd");
*comprLen = c_stream.total_out;
}
/* ===========================================================================
* Test inflateSync()
*/
void test_sync(compr, comprLen, uncompr, uncomprLen)
Byte *compr, *uncompr;
uLong comprLen, uncomprLen;
{
int err;
z_stream d_stream; /* decompression stream */
strcpy((char*)uncompr, "garbage");
d_stream.zalloc = zalloc;
d_stream.zfree = zfree;
d_stream.opaque = (voidpf)0;
d_stream.next_in = compr;
d_stream.avail_in = 2; /* just read the zlib header */
err = inflateInit(&d_stream);
CHECK_ERR(err, "inflateInit");
d_stream.next_out = uncompr;
d_stream.avail_out = (uInt)uncomprLen;
inflate(&d_stream, Z_NO_FLUSH);
CHECK_ERR(err, "inflate");
d_stream.avail_in = (uInt)comprLen-2; /* read all compressed data */
err = inflateSync(&d_stream); /* but skip the damaged part */
CHECK_ERR(err, "inflateSync");
err = inflate(&d_stream, Z_FINISH);
if (err != Z_DATA_ERROR) {
fprintf(stderr, "inflate should report DATA_ERROR\n");
/* Because of incorrect adler32 */
exit(1);
}
err = inflateEnd(&d_stream);
CHECK_ERR(err, "inflateEnd");
printf("after inflateSync(): hel%s\n", (char *)uncompr);
}
/* ===========================================================================
* Test deflate() with preset dictionary
*/
void test_dict_deflate(compr, comprLen)
Byte *compr;
uLong comprLen;
{
z_stream c_stream; /* compression stream */
int err;
c_stream.zalloc = zalloc;
c_stream.zfree = zfree;
c_stream.opaque = (voidpf)0;
err = deflateInit(&c_stream, Z_BEST_COMPRESSION);
CHECK_ERR(err, "deflateInit");
err = deflateSetDictionary(&c_stream,
(const Bytef*)dictionary, (int)sizeof(dictionary));
CHECK_ERR(err, "deflateSetDictionary");
dictId = c_stream.adler;
c_stream.next_out = compr;
c_stream.avail_out = (uInt)comprLen;
c_stream.next_in = (Bytef*)hello;
c_stream.avail_in = (uInt)strlen(hello)+1;
err = deflate(&c_stream, Z_FINISH);
if (err != Z_STREAM_END) {
fprintf(stderr, "deflate should report Z_STREAM_END\n");
exit(1);
}
err = deflateEnd(&c_stream);
CHECK_ERR(err, "deflateEnd");
}
/* ===========================================================================
* Test inflate() with a preset dictionary
*/
void test_dict_inflate(compr, comprLen, uncompr, uncomprLen)
Byte *compr, *uncompr;
uLong comprLen, uncomprLen;
{
int err;
z_stream d_stream; /* decompression stream */
strcpy((char*)uncompr, "garbage");
d_stream.zalloc = zalloc;
d_stream.zfree = zfree;
d_stream.opaque = (voidpf)0;
d_stream.next_in = compr;
d_stream.avail_in = (uInt)comprLen;
err = inflateInit(&d_stream);
CHECK_ERR(err, "inflateInit");
d_stream.next_out = uncompr;
d_stream.avail_out = (uInt)uncomprLen;
for (;;) {
err = inflate(&d_stream, Z_NO_FLUSH);
if (err == Z_STREAM_END) break;
if (err == Z_NEED_DICT) {
if (d_stream.adler != dictId) {
fprintf(stderr, "unexpected dictionary");
exit(1);
}
err = inflateSetDictionary(&d_stream, (const Bytef*)dictionary,
(int)sizeof(dictionary));
}
CHECK_ERR(err, "inflate with dict");
}
err = inflateEnd(&d_stream);
CHECK_ERR(err, "inflateEnd");
if (strcmp((char*)uncompr, hello)) {
fprintf(stderr, "bad inflate with dict\n");
exit(1);
} else {
printf("inflate with dictionary: %s\n", (char *)uncompr);
}
}
/* ===========================================================================
* Usage: example [output.gz [input.gz]]
*/
int main(argc, argv)
int argc;
char *argv[];
{
Byte *compr, *uncompr;
uLong comprLen = 10000*sizeof(int); /* don't overflow on MSDOS */
uLong uncomprLen = comprLen;
static const char* myVersion = ZLIB_VERSION;
if (zlibVersion()[0] != myVersion[0]) {
fprintf(stderr, "incompatible zlib version\n");
exit(1);
} else if (strcmp(zlibVersion(), ZLIB_VERSION) != 0) {
fprintf(stderr, "warning: different zlib version\n");
}
printf("zlib version %s = 0x%04x, compile flags = 0x%lx\n",
ZLIB_VERSION, ZLIB_VERNUM, zlibCompileFlags());
compr = (Byte*)calloc((uInt)comprLen, 1);
uncompr = (Byte*)calloc((uInt)uncomprLen, 1);
/* compr and uncompr are cleared to avoid reading uninitialized
* data and to ensure that uncompr compresses well.
*/
if (compr == Z_NULL || uncompr == Z_NULL) {
printf("out of memory\n");
exit(1);
}
#ifdef Z_SOLO
argc = strlen(argv[0]);
#else
test_compress(compr, comprLen, uncompr, uncomprLen);
test_gzio((argc > 1 ? argv[1] : TESTFILE),
uncompr, uncomprLen);
#endif
test_deflate(compr, comprLen);
test_inflate(compr, comprLen, uncompr, uncomprLen);
test_large_deflate(compr, comprLen, uncompr, uncomprLen);
test_large_inflate(compr, comprLen, uncompr, uncomprLen);
test_flush(compr, &comprLen);
test_sync(compr, comprLen, uncompr, uncomprLen);
comprLen = uncomprLen;
test_dict_deflate(compr, comprLen);
test_dict_inflate(compr, comprLen, uncompr, uncomprLen);
free(compr);
free(uncompr);
return 0;
}

631
examples/minigzip.c Normal file
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@@ -0,0 +1,631 @@
/* minigzip.c -- simulate gzip using the zlib compression library
* Copyright (C) 1995-2006, 2010, 2011 Jean-loup Gailly.
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/*
* minigzip is a minimal implementation of the gzip utility. This is
* only an example of using zlib and isn't meant to replace the
* full-featured gzip. No attempt is made to deal with file systems
* limiting names to 14 or 8+3 characters, etc... Error checking is
* very limited. So use minigzip only for testing; use gzip for the
* real thing. On MSDOS, use only on file names without extension
* or in pipe mode.
*/
/* @(#) $Id$ */
#include "zlib.h"
#include <stdio.h>
#ifdef STDC
# include <string.h>
# include <stdlib.h>
#endif
#ifdef USE_MMAP
# include <sys/types.h>
# include <sys/mman.h>
# include <sys/stat.h>
#endif
#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
# include <fcntl.h>
# include <io.h>
# ifdef UNDER_CE
# include <stdlib.h>
# endif
# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
#else
# define SET_BINARY_MODE(file)
#endif
#ifdef VMS
# define unlink delete
# define GZ_SUFFIX "-gz"
#endif
#ifdef RISCOS
# define unlink remove
# define GZ_SUFFIX "-gz"
# define fileno(file) file->__file
#endif
#if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os
# include <unix.h> /* for fileno */
#endif
#if !defined(Z_HAVE_UNISTD_H) && !defined(_LARGEFILE64_SOURCE)
#ifndef WIN32 /* unlink already in stdio.h for WIN32 */
extern int unlink OF((const char *));
#endif
#endif
#if defined(UNDER_CE)
# include <windows.h>
# define perror(s) pwinerror(s)
/* Map the Windows error number in ERROR to a locale-dependent error
message string and return a pointer to it. Typically, the values
for ERROR come from GetLastError.
The string pointed to shall not be modified by the application,
but may be overwritten by a subsequent call to strwinerror
The strwinerror function does not change the current setting
of GetLastError. */
static char *strwinerror (error)
DWORD error;
{
static char buf[1024];
wchar_t *msgbuf;
DWORD lasterr = GetLastError();
DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
| FORMAT_MESSAGE_ALLOCATE_BUFFER,
NULL,
error,
0, /* Default language */
(LPVOID)&msgbuf,
0,
NULL);
if (chars != 0) {
/* If there is an \r\n appended, zap it. */
if (chars >= 2
&& msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
chars -= 2;
msgbuf[chars] = 0;
}
if (chars > sizeof (buf) - 1) {
chars = sizeof (buf) - 1;
msgbuf[chars] = 0;
}
wcstombs(buf, msgbuf, chars + 1);
LocalFree(msgbuf);
}
else {
sprintf(buf, "unknown win32 error (%ld)", error);
}
SetLastError(lasterr);
return buf;
}
static void pwinerror (s)
const char *s;
{
if (s && *s)
fprintf(stderr, "%s: %s\n", s, strwinerror(GetLastError ()));
else
fprintf(stderr, "%s\n", strwinerror(GetLastError ()));
}
#endif /* UNDER_CE */
#ifndef GZ_SUFFIX
# define GZ_SUFFIX ".gz"
#endif
#define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1)
#define BUFLEN 16384
#define MAX_NAME_LEN 1024
#ifdef MAXSEG_64K
# define local static
/* Needed for systems with limitation on stack size. */
#else
# define local
#endif
#ifdef Z_SOLO
/* for Z_SOLO, create simplified gz* functions using deflate and inflate */
#if defined(Z_HAVE_UNISTD_H) || defined(Z_LARGE)
# include <unistd.h> /* for unlink() */
#endif
void *myalloc OF((void *, unsigned, unsigned));
void myfree OF((void *, void *));
void *myalloc(q, n, m)
void *q;
unsigned n, m;
{
q = Z_NULL;
return calloc(n, m);
}
void myfree(q, p)
void *q, *p;
{
q = Z_NULL;
free(p);
}
typedef struct gzFile_s {
FILE *file;
int write;
int err;
char *msg;
z_stream strm;
} *gzFile;
gzFile gzopen OF((const char *, const char *));
gzFile gzdopen OF((int, const char *));
gzFile gz_open OF((const char *, int, const char *));
gzFile gzopen(path, mode)
const char *path;
const char *mode;
{
return gz_open(path, -1, mode);
}
gzFile gzdopen(fd, mode)
int fd;
const char *mode;
{
return gz_open(NULL, fd, mode);
}
gzFile gz_open(path, fd, mode)
const char *path;
int fd;
const char *mode;
{
gzFile gz;
int ret;
gz = malloc(sizeof(gzFile));
if (gz == NULL)
return NULL;
gz->write = strchr(mode, 'w') != NULL;
gz->strm.zalloc = myalloc;
gz->strm.zfree = myfree;
gz->strm.opaque = Z_NULL;
if (gz->write)
ret = deflateInit2(&(gz->strm), -1, 8, 15 + 16, 8, 0);
else {
gz->strm.next_in = 0;
gz->strm.avail_in = Z_NULL;
ret = inflateInit2(&(gz->strm), 15 + 16);
}
if (ret != Z_OK) {
free(gz);
return NULL;
}
gz->file = path == NULL ? fdopen(fd, gz->write ? "wb" : "rb") :
fopen(path, gz->write ? "wb" : "rb");
if (gz->file == NULL) {
gz->write ? deflateEnd(&(gz->strm)) : inflateEnd(&(gz->strm));
free(gz);
return NULL;
}
gz->err = 0;
gz->msg = "";
return gz;
}
int gzwrite OF((gzFile, const void *, unsigned));
int gzwrite(gz, buf, len)
gzFile gz;
const void *buf;
unsigned len;
{
z_stream *strm;
unsigned char out[BUFLEN];
if (gz == NULL || !gz->write)
return 0;
strm = &(gz->strm);
strm->next_in = (void *)buf;
strm->avail_in = len;
do {
strm->next_out = out;
strm->avail_out = BUFLEN;
(void)deflate(strm, Z_NO_FLUSH);
fwrite(out, 1, BUFLEN - strm->avail_out, gz->file);
} while (strm->avail_out == 0);
return len;
}
int gzread OF((gzFile, void *, unsigned));
int gzread(gz, buf, len)
gzFile gz;
void *buf;
unsigned len;
{
int ret;
unsigned got;
unsigned char in[1];
z_stream *strm;
if (gz == NULL || gz->write)
return 0;
if (gz->err)
return 0;
strm = &(gz->strm);
strm->next_out = (void *)buf;
strm->avail_out = len;
do {
got = fread(in, 1, 1, gz->file);
if (got == 0)
break;
strm->next_in = in;
strm->avail_in = 1;
ret = inflate(strm, Z_NO_FLUSH);
if (ret == Z_DATA_ERROR) {
gz->err = Z_DATA_ERROR;
gz->msg = strm->msg;
return 0;
}
if (ret == Z_STREAM_END)
inflateReset(strm);
} while (strm->avail_out);
return len - strm->avail_out;
}
int gzclose OF((gzFile));
int gzclose(gz)
gzFile gz;
{
z_stream *strm;
unsigned char out[BUFLEN];
if (gz == NULL)
return Z_STREAM_ERROR;
strm = &(gz->strm);
if (gz->write) {
strm->next_in = Z_NULL;
strm->avail_in = 0;
do {
strm->next_out = out;
strm->avail_out = BUFLEN;
(void)deflate(strm, Z_FINISH);
fwrite(out, 1, BUFLEN - strm->avail_out, gz->file);
} while (strm->avail_out == 0);
deflateEnd(strm);
}
else
inflateEnd(strm);
fclose(gz->file);
free(gz);
return Z_OK;
}
const char *gzerror OF((gzFile, int *));
const char *gzerror(gz, err)
gzFile gz;
int *err;
{
*err = gz->err;
return gz->msg;
}
#endif
char *prog;
void error OF((const char *msg));
void gz_compress OF((FILE *in, gzFile out));
#ifdef USE_MMAP
int gz_compress_mmap OF((FILE *in, gzFile out));
#endif
void gz_uncompress OF((gzFile in, FILE *out));
void file_compress OF((char *file, char *mode));
void file_uncompress OF((char *file));
int main OF((int argc, char *argv[]));
/* ===========================================================================
* Display error message and exit
*/
void error(msg)
const char *msg;
{
fprintf(stderr, "%s: %s\n", prog, msg);
exit(1);
}
/* ===========================================================================
* Compress input to output then close both files.
*/
void gz_compress(in, out)
FILE *in;
gzFile out;
{
local char buf[BUFLEN];
int len;
int err;
#ifdef USE_MMAP
/* Try first compressing with mmap. If mmap fails (minigzip used in a
* pipe), use the normal fread loop.
*/
if (gz_compress_mmap(in, out) == Z_OK) return;
#endif
for (;;) {
len = (int)fread(buf, 1, sizeof(buf), in);
if (ferror(in)) {
perror("fread");
exit(1);
}
if (len == 0) break;
if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err));
}
fclose(in);
if (gzclose(out) != Z_OK) error("failed gzclose");
}
#ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */
/* Try compressing the input file at once using mmap. Return Z_OK if
* if success, Z_ERRNO otherwise.
*/
int gz_compress_mmap(in, out)
FILE *in;
gzFile out;
{
int len;
int err;
int ifd = fileno(in);
caddr_t buf; /* mmap'ed buffer for the entire input file */
off_t buf_len; /* length of the input file */
struct stat sb;
/* Determine the size of the file, needed for mmap: */
if (fstat(ifd, &sb) < 0) return Z_ERRNO;
buf_len = sb.st_size;
if (buf_len <= 0) return Z_ERRNO;
/* Now do the actual mmap: */
buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0);
if (buf == (caddr_t)(-1)) return Z_ERRNO;
/* Compress the whole file at once: */
len = gzwrite(out, (char *)buf, (unsigned)buf_len);
if (len != (int)buf_len) error(gzerror(out, &err));
munmap(buf, buf_len);
fclose(in);
if (gzclose(out) != Z_OK) error("failed gzclose");
return Z_OK;
}
#endif /* USE_MMAP */
/* ===========================================================================
* Uncompress input to output then close both files.
*/
void gz_uncompress(in, out)
gzFile in;
FILE *out;
{
local char buf[BUFLEN];
int len;
int err;
for (;;) {
len = gzread(in, buf, sizeof(buf));
if (len < 0) error (gzerror(in, &err));
if (len == 0) break;
if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
error("failed fwrite");
}
}
if (fclose(out)) error("failed fclose");
if (gzclose(in) != Z_OK) error("failed gzclose");
}
/* ===========================================================================
* Compress the given file: create a corresponding .gz file and remove the
* original.
*/
void file_compress(file, mode)
char *file;
char *mode;
{
local char outfile[MAX_NAME_LEN];
FILE *in;
gzFile out;
if (strlen(file) + strlen(GZ_SUFFIX) >= sizeof(outfile)) {
fprintf(stderr, "%s: filename too long\n", prog);
exit(1);
}
strcpy(outfile, file);
strcat(outfile, GZ_SUFFIX);
in = fopen(file, "rb");
if (in == NULL) {
perror(file);
exit(1);
}
out = gzopen(outfile, mode);
if (out == NULL) {
fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);
exit(1);
}
gz_compress(in, out);
unlink(file);
}
/* ===========================================================================
* Uncompress the given file and remove the original.
*/
void file_uncompress(file)
char *file;
{
local char buf[MAX_NAME_LEN];
char *infile, *outfile;
FILE *out;
gzFile in;
size_t len = strlen(file);
if (len + strlen(GZ_SUFFIX) >= sizeof(buf)) {
fprintf(stderr, "%s: filename too long\n", prog);
exit(1);
}
strcpy(buf, file);
if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {
infile = file;
outfile = buf;
outfile[len-3] = '\0';
} else {
outfile = file;
infile = buf;
strcat(infile, GZ_SUFFIX);
}
in = gzopen(infile, "rb");
if (in == NULL) {
fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);
exit(1);
}
out = fopen(outfile, "wb");
if (out == NULL) {
perror(file);
exit(1);
}
gz_uncompress(in, out);
unlink(infile);
}
/* ===========================================================================
* Usage: minigzip [-c] [-d] [-f] [-h] [-r] [-1 to -9] [files...]
* -c : write to standard output
* -d : decompress
* -f : compress with Z_FILTERED
* -h : compress with Z_HUFFMAN_ONLY
* -r : compress with Z_RLE
* -1 to -9 : compression level
*/
int main(argc, argv)
int argc;
char *argv[];
{
int copyout = 0;
int uncompr = 0;
gzFile file;
char *bname, outmode[20];
strcpy(outmode, "wb6 ");
prog = argv[0];
bname = strrchr(argv[0], '/');
if (bname)
bname++;
else
bname = argv[0];
argc--, argv++;
if (!strcmp(bname, "gunzip"))
uncompr = 1;
else if (!strcmp(bname, "zcat"))
copyout = uncompr = 1;
while (argc > 0) {
if (strcmp(*argv, "-c") == 0)
copyout = 1;
else if (strcmp(*argv, "-d") == 0)
uncompr = 1;
else if (strcmp(*argv, "-f") == 0)
outmode[3] = 'f';
else if (strcmp(*argv, "-h") == 0)
outmode[3] = 'h';
else if (strcmp(*argv, "-r") == 0)
outmode[3] = 'R';
else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' &&
(*argv)[2] == 0)
outmode[2] = (*argv)[1];
else
break;
argc--, argv++;
}
if (outmode[3] == ' ')
outmode[3] = 0;
if (argc == 0) {
SET_BINARY_MODE(stdin);
SET_BINARY_MODE(stdout);
if (uncompr) {
file = gzdopen(fileno(stdin), "rb");
if (file == NULL) error("can't gzdopen stdin");
gz_uncompress(file, stdout);
} else {
file = gzdopen(fileno(stdout), outmode);
if (file == NULL) error("can't gzdopen stdout");
gz_compress(stdin, file);
}
} else {
if (copyout) {
SET_BINARY_MODE(stdout);
}
do {
if (uncompr) {
if (copyout) {
file = gzopen(*argv, "rb");
if (file == NULL)
fprintf(stderr, "%s: can't gzopen %s\n", prog, *argv);
else
gz_uncompress(file, stdout);
} else {
file_uncompress(*argv);
}
} else {
if (copyout) {
FILE * in = fopen(*argv, "rb");
if (in == NULL) {
perror(*argv);
} else {
file = gzdopen(fileno(stdout), outmode);
if (file == NULL) error("can't gzdopen stdout");
gz_compress(in, file);
}
} else {
file_compress(*argv, outmode);
}
}
} while (argv++, --argc);
}
return 0;
}