www.pudn.com > gzip_win.zip > zip.c

/* zip.c -- compress files to the gzip or pkzip format 
 * Copyright (C) 1992-1993 Jean-loup Gailly 
 * This is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU General Public License, see the file COPYING. 
 */ 
 
#ifdef RCSID 
static char rcsid[] = "$Id: zip.c,v 0.17 1993/06/10 13:29:25 jloup Exp $"; 
#endif 
 
#include  
#include  
 
#include "tailor.h" 
#include "gzip.h" 
#include "crypt.h" 
 
#ifdef HAVE_UNISTD_H 
#  include  
#endif 
#ifndef NO_FCNTL_H 
#  include  
#endif 
 
local ulg crc;       /* crc on uncompressed file data */ 
long header_bytes;   /* number of bytes in gzip header */ 
 
/* =========================================================================== 
 * Deflate in to out. 
 * IN assertions: the input and output buffers are cleared. 
 *   The variables time_stamp and save_orig_name are initialized. 
 */ 
int zip(in, out) 
    int in, out;            /* input and output file descriptors */ 
{ 
    uch  flags = 0;         /* general purpose bit flags */ 
    ush  attr = 0;          /* ascii/binary flag */ 
    ush  deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */ 
 
    ifd = in; 
    ofd = out; 
    outcnt = 0; 
 
    /* Write the header to the gzip file. See algorithm.doc for the format */ 
 
    method = DEFLATED; 
    put_byte(GZIP_MAGIC[0]); /* magic header */ 
    put_byte(GZIP_MAGIC[1]); 
    put_byte(DEFLATED);      /* compression method */ 
 
    if (save_orig_name) { 
	flags |= ORIG_NAME; 
    } 
    put_byte(flags);         /* general flags */ 
    put_long(time_stamp); 
 
    /* Write deflated file to zip file */ 
    crc = updcrc(0, 0); 
 
    bi_init(out); 
    ct_init(&attr, &method); 
    lm_init(level, &deflate_flags); 
 
    put_byte((uch)deflate_flags); /* extra flags */ 
    put_byte(OS_CODE);            /* OS identifier */ 
 
    if (save_orig_name) { 
	char *p = basename(ifname); /* Don't save the directory part. */ 
	do { 
	    put_char(*p); 
	} while (*p++); 
    } 
    header_bytes = (long)outcnt; 
 
    (void)deflate(); 
 
#if !defined(NO_SIZE_CHECK) && !defined(RECORD_IO) 
  /* Check input size (but not in VMS -- variable record lengths mess it up) 
   * and not on MSDOS -- diet in TSR mode reports an incorrect file size) 
   */ 
    if (ifile_size != -1L && isize != (ulg)ifile_size) { 
	Trace((stderr, " actual=%ld, read=%ld ", ifile_size, isize)); 
	fprintf(stderr, "%s: %s: file size changed while zipping\n", 
		progname, ifname); 
    } 
#endif 
 
    /* Write the crc and uncompressed size */ 
    put_long(crc); 
    put_long(isize); 
    header_bytes += 2*sizeof(long); 
 
    flush_outbuf(); 
    return OK; 
} 
 
 
/* =========================================================================== 
 * Read a new buffer from the current input file, perform end-of-line 
 * translation, and update the crc and input file size. 
 * IN assertion: size >= 2 (for end-of-line translation) 
 */ 
int file_read(buf, size) 
    char *buf; 
    unsigned size; 
{ 
    unsigned len; 
 
    Assert(insize == 0, "inbuf not empty"); 
 
    len = read(ifd, buf, size); 
    if (len == (unsigned)(-1) || len == 0) return (int)len; 
 
    crc = updcrc((uch*)buf, len); 
    isize += (ulg)len; 
    return (int)len; 
}