zip.c

   1 /* zip.c -- compress files to the gzip or pkzip format
   2
   3    Copyright (C) 1997-1999, 2006-2007, 2009-2018 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 local ulg crc;       /* crc on uncompressed file data */
  27 off_t header_bytes;   /* number of bytes in gzip header */
  28
  29 /* ===========================================================================
  30  * Deflate in to out.
  31  * IN assertions: the input and output buffers are cleared.
  32  *   The variables time_stamp and save_orig_name are initialized.
  33  */
  34 int zip(in, out)
  35     int in, out;            /* input and output file descriptors */
  36 {
  37     uch  flags = 0;         /* general purpose bit flags */
  38     ush  attr = 0;          /* ascii/binary flag */
  39     ush  deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
  40     ulg  stamp;
  41
  42     ifd = in;
  43     ofd = out;
  44     outcnt = 0;
  45
  46     /* Write the header to the gzip file. See algorithm.doc for the format */
  47
  48     method = DEFLATED;
  49     put_byte(GZIP_MAGIC[0]); /* magic header */
  50     put_byte(GZIP_MAGIC[1]);
  51     put_byte(DEFLATED);      /* compression method */
  52
  53     if (save_orig_name) {
  54         flags |= ORIG_NAME;
  55     }
  56     put_byte(flags);         /* general flags */
  57     if (time_stamp.tv_nsec < 0)
  58       stamp = 0;
  59     else if (0 < time_stamp.tv_sec && time_stamp.tv_sec <= 0xffffffff)
  60       stamp = time_stamp.tv_sec;
  61     else
  62       {
  63         /* It's intended that timestamp 0 generates this warning,
  64            since gzip format reserves 0 for something else.  */
  65         warning ("file timestamp out of range for gzip format");
  66         stamp = 0;
  67       }
  68     put_long (stamp);
  69
  70     /* Write deflated file to zip file */
  71     crc = updcrc(0, 0);
  72
  73     bi_init(out);
  74     ct_init(&attr, &method);
  75     lm_init(level, &deflate_flags);
  76
  77     put_byte((uch)deflate_flags); /* extra flags */
  78     put_byte(OS_CODE);            /* OS identifier */
  79
  80     if (save_orig_name) {
  81         char *p = gzip_base_name (ifname); /* Don't save the directory part. */
  82         do {
  83             put_byte (*p);
  84         } while (*p++);
  85     }
  86     header_bytes = (off_t)outcnt;
  87
  88     (void)deflate();
  89
  90 #ifndef NO_SIZE_CHECK
  91   /* Check input size
  92    * (but not on MSDOS -- diet in TSR mode reports an incorrect file size)
  93    */
  94     if (ifile_size != -1L && bytes_in != ifile_size) {
  95         fprintf(stderr, "%s: %s: file size changed while zipping\n",
  96                 program_name, ifname);
  97     }
  98 #endif
  99
 100     /* Write the crc and uncompressed size */
 101     put_long(crc);
 102     put_long((ulg)bytes_in);
 103     header_bytes += 2*4;
 104
 105     flush_outbuf();
 106     return OK;
 107 }
 108
 109
 110 /* ===========================================================================
 111  * Read a new buffer from the current input file, perform end-of-line
 112  * translation, and update the crc and input file size.
 113  * IN assertion: size >= 2 (for end-of-line translation)
 114  */
 115 int file_read(buf, size)
 116     char *buf;
 117     unsigned size;
 118 {
 119     unsigned len;
 120
 121     Assert(insize == 0, "inbuf not empty");
 122
 123     len = read_buffer (ifd, buf, size);
 124     if (len == 0) return (int)len;
 125     if (len == (unsigned)-1) {
 126         read_error();
 127         return EOF;
 128     }
 129
 130     crc = updcrc((uch*)buf, len);
 131     bytes_in += (off_t)len;
 132     return (int)len;
 133 }