zip.c

   1 /* zip.c -- compress files to the gzip or pkzip format
   2
   3    Copyright (C) 1997-1999, 2006-2007, 2009-2013 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 3, 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 #include <config.h>
  21 #include <ctype.h>
  22
  23 #include "tailor.h"
  24 #include "gzip.h"
  25
  26 #include <unistd.h>
  27 #include <fcntl.h>
  28
  29 local ulg crc;       /* crc on uncompressed file data */
  30 off_t header_bytes;   /* number of bytes in gzip header */
  31
  32 /* ===========================================================================
  33  * Deflate in to out.
  34  * IN assertions: the input and output buffers are cleared.
  35  *   The variables time_stamp and save_orig_name are initialized.
  36  */
  37 int zip(in, out)
  38     int in, out;            /* input and output file descriptors */
  39 {
  40     uch  flags = 0;         /* general purpose bit flags */
  41     ush  attr = 0;          /* ascii/binary flag */
  42     ush  deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
  43     ulg  stamp;
  44
  45     ifd = in;
  46     ofd = out;
  47     outcnt = 0;
  48
  49     /* Write the header to the gzip file. See algorithm.doc for the format */
  50
  51     method = DEFLATED;
  52     put_byte(GZIP_MAGIC[0]); /* magic header */
  53     put_byte(GZIP_MAGIC[1]);
  54     put_byte(DEFLATED);      /* compression method */
  55
  56     if (save_orig_name) {
  57         flags |= ORIG_NAME;
  58     }
  59     put_byte(flags);         /* general flags */
  60     stamp = (0 <= time_stamp.tv_sec && time_stamp.tv_sec <= 0xffffffff
  61              ? (ulg) time_stamp.tv_sec
  62              : (ulg) 0);
  63     put_long (stamp);
  64
  65     /* Write deflated file to zip file */
  66     crc = updcrc(0, 0);
  67
  68     bi_init(out);
  69     ct_init(&attr, &method);
  70     lm_init(level, &deflate_flags);
  71
  72     put_byte((uch)deflate_flags); /* extra flags */
  73     put_byte(OS_CODE);            /* OS identifier */
  74
  75     if (save_orig_name) {
  76         char *p = gzip_base_name (ifname); /* Don't save the directory part. */
  77         do {
  78             put_byte (*p);
  79         } while (*p++);
  80     }
  81     header_bytes = (off_t)outcnt;
  82
  83     (void)deflate();
  84
  85 #ifndef NO_SIZE_CHECK
  86   /* Check input size (but not in VMS -- variable record lengths mess it up)
  87    * and not on MSDOS -- diet in TSR mode reports an incorrect file size)
  88    */
  89     if (ifile_size != -1L && bytes_in != ifile_size) {
  90         fprintf(stderr, "%s: %s: file size changed while zipping\n",
  91                 program_name, ifname);
  92     }
  93 #endif
  94
  95     /* Write the crc and uncompressed size */
  96     put_long(crc);
  97     put_long((ulg)bytes_in);
  98     header_bytes += 2*4;
  99
 100     flush_outbuf();
 101     return OK;
 102 }
 103
 104
 105 /* ===========================================================================
 106  * Read a new buffer from the current input file, perform end-of-line
 107  * translation, and update the crc and input file size.
 108  * IN assertion: size >= 2 (for end-of-line translation)
 109  */
 110 int file_read(buf, size)
 111     char *buf;
 112     unsigned size;
 113 {
 114     unsigned len;
 115
 116     Assert(insize == 0, "inbuf not empty");
 117
 118     len = read_buffer (ifd, buf, size);
 119     if (len == 0) return (int)len;
 120     if (len == (unsigned)-1) {
 121         read_error();
 122         return EOF;
 123     }
 124
 125     crc = updcrc((uch*)buf, len);
 126     bytes_in += (off_t)len;
 127     return (int)len;
 128 }