1 /* zip.c -- compress files to the gzip or pkzip format
2 * Copyright (C) 1992-1993 Jean-loup Gailly
3 * This is free software; you can redistribute it and/or modify it under the
4 * terms of the GNU General Public License, see the file COPYING.
8 static char rcsid[] = "$Id: zip.c,v 0.17 1993/06/10 13:29:25 jloup Exp $";
25 local ulg crc; /* crc on uncompressed file data */
26 off_t header_bytes; /* number of bytes in gzip header */
28 /* ===========================================================================
30 * IN assertions: the input and output buffers are cleared.
31 * The variables time_stamp and save_orig_name are initialized.
34 int in, out; /* input and output file descriptors */
36 uch flags = 0; /* general purpose bit flags */
37 ush attr = 0; /* ascii/binary flag */
38 ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
44 /* Write the header to the gzip file. See algorithm.doc for the format */
47 put_byte(GZIP_MAGIC[0]); /* magic header */
48 put_byte(GZIP_MAGIC[1]);
49 put_byte(DEFLATED); /* compression method */
54 put_byte(flags); /* general flags */
55 put_long(time_stamp == (time_stamp & 0xffffffff)
56 ? (ulg)time_stamp : (ulg)0);
58 /* Write deflated file to zip file */
62 ct_init(&attr, &method);
63 lm_init(level, &deflate_flags);
65 put_byte((uch)deflate_flags); /* extra flags */
66 put_byte(OS_CODE); /* OS identifier */
69 char *p = base_name(ifname); /* Don't save the directory part. */
74 header_bytes = (off_t)outcnt;
78 #if !defined(NO_SIZE_CHECK) && !defined(RECORD_IO)
79 /* Check input size (but not in VMS -- variable record lengths mess it up)
80 * and not on MSDOS -- diet in TSR mode reports an incorrect file size)
82 if (ifile_size != -1L && bytes_in != ifile_size) {
83 fprintf(stderr, "%s: %s: file size changed while zipping\n",
88 /* Write the crc and uncompressed size */
90 put_long((ulg)bytes_in);
91 header_bytes += 2*sizeof(long);
98 /* ===========================================================================
99 * Read a new buffer from the current input file, perform end-of-line
100 * translation, and update the crc and input file size.
101 * IN assertion: size >= 2 (for end-of-line translation)
103 int file_read(buf, size)
109 Assert(insize == 0, "inbuf not empty");
111 len = read(ifd, buf, size);
112 if (len == 0) return (int)len;
113 if (len == (unsigned)-1) {
118 crc = updcrc((uch*)buf, len);
119 bytes_in += (off_t)len;