1 /* zip.c -- compress files to the gzip or pkzip format
3 Copyright (C) 1997, 1998, 1999, 2006 Free Software Foundation, Inc.
4 Copyright (C) 1992-1993 Jean-loup Gailly
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)
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.
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. */
21 static char rcsid[] = "$Id: zip.c,v 1.6 2006/12/11 18:54:39 eggert Exp $";
40 local ulg crc; /* crc on uncompressed file data */
41 off_t header_bytes; /* number of bytes in gzip header */
43 /* ===========================================================================
45 * IN assertions: the input and output buffers are cleared.
46 * The variables time_stamp and save_orig_name are initialized.
49 int in, out; /* input and output file descriptors */
51 uch flags = 0; /* general purpose bit flags */
52 ush attr = 0; /* ascii/binary flag */
53 ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
60 /* Write the header to the gzip file. See algorithm.doc for the format */
63 put_byte(GZIP_MAGIC[0]); /* magic header */
64 put_byte(GZIP_MAGIC[1]);
65 put_byte(DEFLATED); /* compression method */
70 put_byte(flags); /* general flags */
71 stamp = (0 <= time_stamp.tv_sec && time_stamp.tv_sec <= 0xffffffff
72 ? (ulg) time_stamp.tv_sec
76 /* Write deflated file to zip file */
80 ct_init(&attr, &method);
81 lm_init(level, &deflate_flags);
83 put_byte((uch)deflate_flags); /* extra flags */
84 put_byte(OS_CODE); /* OS identifier */
87 char *p = gzip_base_name (ifname); /* Don't save the directory part. */
92 header_bytes = (off_t)outcnt;
96 #if !defined(NO_SIZE_CHECK) && !defined(RECORD_IO)
97 /* Check input size (but not in VMS -- variable record lengths mess it up)
98 * and not on MSDOS -- diet in TSR mode reports an incorrect file size)
100 if (ifile_size != -1L && bytes_in != ifile_size) {
101 fprintf(stderr, "%s: %s: file size changed while zipping\n",
102 program_name, ifname);
106 /* Write the crc and uncompressed size */
108 put_long((ulg)bytes_in);
109 header_bytes += 2*sizeof(long);
116 /* ===========================================================================
117 * Read a new buffer from the current input file, perform end-of-line
118 * translation, and update the crc and input file size.
119 * IN assertion: size >= 2 (for end-of-line translation)
121 int file_read(buf, size)
127 Assert(insize == 0, "inbuf not empty");
129 len = read_buffer (ifd, buf, size);
130 if (len == 0) return (int)len;
131 if (len == (unsigned)-1) {
136 crc = updcrc((uch*)buf, len);
137 bytes_in += (off_t)len;