gzip.c

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/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
 * Copyright (C) 1992-1993 Jean-loup Gailly
 * The unzip code was written and put in the public domain by Mark Adler.
 * Portions of the lzw code are derived from the public domain 'compress'
 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
 * Ken Turkowski, Dave Mack and Peter Jannesen.
 *
 * See the license_msg below and the file COPYING for the software license.
 * See the file algorithm.doc for the compression algorithms and file formats.
 */

/* Compress files with zip algorithm and 'compress' interface.
 * See usage() and help() functions below for all options.
 * Outputs:
 *        file.gz:   compressed file with same mode, owner, and utimes
 *     or stdout with -c option or if stdin used as input.
 * If the output file name had to be truncated, the original name is kept
 * in the compressed file.
 * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
 *
 * Using gz on MSDOS would create too many file name conflicts. For
 * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
 * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
 * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
 * too heavily. There is no ideal solution given the MSDOS 8+3 limitation. 
 *
 * For the meaning of all compilation flags, see comments in Makefile.in.
 */

#include <ctype.h>
#include <sys/types.h>
#include <signal.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include "tailor.h"
#include "gzip.h"
#include "lzw.h"
#include "revision.h"
#include "getopt.h"

char *strlwr(char *s);
		/* configuration */

#ifdef NO_TIME_H
#  include <sys/time.h>
#else
#  include <time.h>
#endif

#ifndef NO_FCNTL_H
#  include <fcntl.h>
#endif

#ifdef HAVE_UNISTD_H
#  include <unistd.h>
#endif

#if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
#  include <stdlib.h>
#else
   extern int errno;
#endif

#if defined(DIRENT)
#  include <dirent.h>
   typedef struct dirent dir_type;
#  define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
#  define DIR_OPT "DIRENT"
#else
#  define NLENGTH(dirent) ((dirent)->d_namlen)
#  ifdef SYSDIR
#    include <sys/dir.h>
     typedef struct direct dir_type;
#    define DIR_OPT "SYSDIR"
#  else
#    ifdef SYSNDIR
#      include <sys/ndir.h>
       typedef struct direct dir_type;
#      define DIR_OPT "SYSNDIR"
#    else
#      ifdef NDIR
#        include <ndir.h>
         typedef struct direct dir_type;
#        define DIR_OPT "NDIR"
#      else
#        define NO_DIR
#        define DIR_OPT "NO_DIR"
#      endif
#    endif
#  endif
#endif

#ifndef NO_UTIME
#  ifndef NO_UTIME_H
#    include <utime.h>
#    define TIME_OPT "UTIME"
#  else
#    ifdef HAVE_SYS_UTIME_H
#      include <sys/utime.h>
#      define TIME_OPT "SYS_UTIME"
#    else
       struct utimbuf {
         time_t actime;
         time_t modtime;
       };
#      define TIME_OPT ""
#    endif
#  endif
#else
#  define TIME_OPT "NO_UTIME"
#endif

#if !defined(S_ISDIR) && defined(S_IFDIR)
#  define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
#if !defined(S_ISREG) && defined(S_IFREG)
#  define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#endif

typedef RETSIGTYPE (*sig_type) OF((int));

#ifndef	O_BINARY
#  define  O_BINARY  0  /* creation mode for open() */
#endif

#ifndef O_CREAT
   /* Pure BSD system? */
#  include <sys/file.h>
#  ifndef O_CREAT
#    define O_CREAT FCREAT
#  endif
#  ifndef O_EXCL
#    define O_EXCL FEXCL
#  endif
#endif

#ifndef S_IRUSR
#  define S_IRUSR 0400
#endif
#ifndef S_IWUSR
#  define S_IWUSR 0200
#endif
#define RW_USER (S_IRUSR | S_IWUSR)  /* creation mode for open() */

#ifndef MAX_PATH_LEN
#  define MAX_PATH_LEN   1024 /* max pathname length */
#endif

#ifndef SEEK_END
#  define SEEK_END 2
#endif

#ifdef NO_OFF_T
  typedef long off_t;
  off_t lseek OF((int fd, off_t offset, int whence));
#endif

/* Separator for file name parts (see shorten_name()) */
#ifdef NO_MULTIPLE_DOTS
#  define PART_SEP "-"
#else
#  define PART_SEP "."
#endif

		/* global buffers */ 

DECLARE(uch, inbuf,  INBUFSIZ +INBUF_EXTRA);
//uch *inbuf;
DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
DECLARE(ush, d_buf,  DIST_BUFSIZE);
DECLARE(uch, window, 2L*WSIZE);
#ifndef MAXSEG_64K
    DECLARE(ush, tab_prefix, 1L<<BITS);
#else
    DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
    DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
#endif

		/* local variables */

int ascii = 0;        /* convert end-of-lines to local OS conventions */
int to_stdout = 0;    /* output to stdout (-c) */
int decompress = 0;   /* decompress (-d) */
int force = 0;        /* don't ask questions, compress links (-f) */
int no_name = -1;     /* don't save or restore the original file name */
int no_time = -1;     /* don't save or restore the original file time */
int recursive = 0;    /* recurse through directories (-r) */
int list = 0;         /* list the file contents (-l) */
int verbose = 0;      /* be verbose (-v) */
int quiet = 0;        /* be very quiet (-q) */
int do_lzw = 0;       /* generate output compatible with old compress (-Z) */
int test = 0;         /* test .gz file integrity */
char *progname;       /* program name */
int maxbits = BITS;   /* max bits per code for LZW */
int method = DEFLATED;/* compression method */
int level = 6;        /* compression level */
int exit_code = OK;   /* program exit code */
int save_orig_name;   /* set if original name must be saved */
int last_member;      /* set for .zip and .Z files */
int part_nb;          /* number of parts in .gz file */
long time_stamp;      /* original time stamp (modification time) */
long ifile_size;      /* input file size, -1 for devices (debug only) */
char *env;            /* contents of GZIP env variable */
char **args = NULL;   /* argv pointer if GZIP env variable defined */
char z_suffix[MAX_SUFFIX+1]; /* default suffix (can be set with --suffix) */
int  z_len;           /* strlen(z_suffix) */

long bytes_in;             /* number of input bytes */
long bytes_out;            /* number of output bytes */
long total_in = 0;         /* input bytes for all files */
long total_out = 0;        /* output bytes for all files */
char ifname[MAX_PATH_LEN]; /* input file name */
char ofname[MAX_PATH_LEN]; /* output file name */
int  remove_ofname = 0;	   /* remove output file on error */
struct stat istat;         /* status for input file */
int  ifd;                  /* input file descriptor */
int  ofd;                  /* output file descriptor */
char *ungzipbuf;	
int gziplen ;
char *gzipbuf;
unsigned insize;           /* valid bytes in inbuf */
unsigned inptr;            /* index of next byte to be processed in inbuf */
//unsigned outcnt;           /* bytes in output buffer */
long  outcnt;           /* bytes in output buffer */
long  out_len = 0;

/* local functions */

int ungzip   OF((char *, int, char *, long, long *));
local int  get_method   OF(());
//local void copy_stat    OF((struct stat *ifstat));
local void do_exit      OF((int exitcode));
int (*work) OF((int infile, int outfile)) = zip; /* function to call */

#ifndef NO_UTIME
local void reset_times  OF((char *name, struct stat *statb));
#endif

#define strequ(s1, s2) (strcmp((s1),(s2)) == 0)

/* ========================================================================
 * Compress or decompress the given file
 */
int ungzip(char *inbuf, int len, char *outbuf, long out_size, long *outlen)
{
	gzipbuf = malloc(MAX_INBUF);
	memcpy(gzipbuf, inbuf, len);
	gziplen = len;
	decompress = 1;
	part_nb = 0;

	if (inbuf == NULL)
	{
		WARN((stderr, "ungzip is NULL\n"));
		return NULL_ERR;
	}

	if (len <= 0)
	{
		WARN((stderr, " len of ungzip is error\n"));
		return SIZE_ERR;
 	}
	if (decompress)
    	{
		method = get_method(); 
		if (method < 0)
		{
			WARN((stderr, "method is error\n"));
			return METHOD_ERR;              
		}
    	}

	/* Actually do the compression/decompression. Loop over zipped members.
	*/
	for (;;) 
    	{
		if (unzip(inbuf, outbuf) != OK) 
		{
			method = -1; /* force cleanup */
			//break;
			WARN((stderr, "unzip error\n"));
			return UNZIP_ERR;
		
		}
		
		if (out_size != out_len)
				return -1;
		*outlen = out_len;
		outlen = &out_len;
   		outcnt = 0;
		if (!decompress || last_member || inptr == insize) 
			break;
		bytes_out = 0;    /* required for length check */
    	}
	free(gzipbuf);

	return OK;
}

/* ========================================================================
 * Check the magic number of the input file and update ofname if an
 * original name was given and to_stdout is not set.
 * Return the compression method, -1 for error, -2 for warning.
 * Set inptr to the offset of the next byte to be processed.
 * Updates time_stamp if there is one and --no-time is not used.
 * This function may be called repeatedly for an input file consisting
 * of several contiguous gzip'ed members.
 * IN assertions: there is at least one remaining compressed member.