/* minigzip.c -- simulate gzip using the zlib compression library | |
* Copyright (C) 1995-2005 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 <stdio.h> | |
#include "zlib.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> | |
# 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 | |
#ifndef WIN32 /* unlink already in stdio.h for WIN32 */ | |
extern int unlink OF((const char *)); | |
#endif | |
#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 | |
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; | |
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; | |
uInt len = (uInt)strlen(file); | |
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 [-d] [-f] [-h] [-r] [-1 to -9] [files...] | |
* -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 uncompr = 0; | |
gzFile file; | |
char outmode[20]; | |
strcpy(outmode, "wb6 "); | |
prog = argv[0]; | |
argc--, argv++; | |
while (argc > 0) { | |
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 { | |
do { | |
if (uncompr) { | |
file_uncompress(*argv); | |
} else { | |
file_compress(*argv, outmode); | |
} | |
} while (argv++, --argc); | |
} | |
return 0; | |
} |