zip.c

   1 /* zip.c -- compress files to the gzip or pkzip format
   2
   3    Copyright (C) 1997, 1998, 1999, 2006 Free Software Foundation, Inc.
   4    Copyright (C) 1992-1993 Jean-loup Gailly
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 #ifdef RCSID
  21 static char rcsid[] = "$Id$";
  22 #endif
  23
  24 #include <config.h>
  25 #include <ctype.h>
  26
  27 #include "tailor.h"
  28 #include "gzip.h"
  29 #include "crypt.h"
  30
  31 #ifdef HAVE_UNISTD_H
  32 #  include <unistd.h>
  33 #endif
  34 #ifdef HAVE_FCNTL_H
  35 #  include <fcntl.h>
  36 #endif
  37
  38 local ulg crc;       /* crc on uncompressed file data */
  39 off_t header_bytes;   /* number of bytes in gzip header */
  40
  41 /* ===========================================================================
  42  * Deflate in to out.
  43  * IN assertions: the input and output buffers are cleared.
  44  *   The variables time_stamp and save_orig_name are initialized.
  45  */
  46 int zip(in, out)
  47     int in, out;            /* input and output file descriptors */
  48 {
  49     uch  flags = 0;         /* general purpose bit flags */
  50     ush  attr = 0;          /* ascii/binary flag */
  51     ush  deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
  52     ulg  stamp;
  53
  54     ifd = in;
  55     ofd = out;
  56     outcnt = 0;
  57
  58     /* Write the header to the gzip file. See algorithm.doc for the format */
  59
  60     method = DEFLATED;
  61     put_byte(GZIP_MAGIC[0]); /* magic header */
  62     put_byte(GZIP_MAGIC[1]);
  63     put_byte(DEFLATED);      /* compression method */
  64
  65     if (save_orig_name) {
  66         flags |= ORIG_NAME;
  67     }
  68     put_byte(flags);         /* general flags */
  69     stamp = (0 <= time_stamp.tv_sec && time_stamp.tv_sec <= 0xffffffff
  70              ? (ulg) time_stamp.tv_sec
  71              : (ulg) 0);
  72     put_long (stamp);
  73
  74     /* Write deflated file to zip file */
  75     crc = updcrc(0, 0);
  76
  77     bi_init(out);
  78     ct_init(&attr, &method);
  79     lm_init(level, &deflate_flags);
  80
  81     put_byte((uch)deflate_flags); /* extra flags */
  82     put_byte(OS_CODE);            /* OS identifier */
  83
  84     if (save_orig_name) {
  85         char *p = gzip_base_name (ifname); /* Don't save the directory part. */
  86         do {
  87             put_char(*p);
  88         } while (*p++);
  89     }
  90     header_bytes = (off_t)outcnt;
  91
  92     (void)deflate();
  93
  94 #if !defined(NO_SIZE_CHECK) && !defined(RECORD_IO)
  95   /* Check input size (but not in VMS -- variable record lengths mess it up)
  96    * and not on MSDOS -- diet in TSR mode reports an incorrect file size)
  97    */
  98     if (ifile_size != -1L && bytes_in != ifile_size) {
  99         fprintf(stderr, "%s: %s: file size changed while zipping\n",
 100                 program_name, ifname);
 101     }
 102 #endif
 103
 104     /* Write the crc and uncompressed size */
 105     put_long(crc);
 106     put_long((ulg)bytes_in);
 107     header_bytes += 2*sizeof(long);
 108
 109     flush_outbuf();
 110     return OK;
 111 }
 112
 113
 114 /* ===========================================================================
 115  * Read a new buffer from the current input file, perform end-of-line
 116  * translation, and update the crc and input file size.
 117  * IN assertion: size >= 2 (for end-of-line translation)
 118  */
 119 int file_read(buf, size)
 120     char *buf;
 121     unsigned size;
 122 {
 123     unsigned len;
 124
 125     Assert(insize == 0, "inbuf not empty");
 126
 127     len = read(ifd, buf, size);
 128     if (len == 0) return (int)len;
 129     if (len == (unsigned)-1) {
 130         read_error();
 131         return EOF;
 132     }
 133
 134     crc = updcrc((uch*)buf, len);
 135     bytes_in += (off_t)len;
 136     return (int)len;
 137 }