1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) tons of folks.  Tracking down who wrote what
6 * isn't something I'm going to worry about...  If you wrote something
7 * here, please feel free to acknowledge your work.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
24 * Permission has been granted to redistribute this code under the GPL.
25 *
26 */
27
28#include <stdio.h>
29#include <sys/stat.h>
30#include "libbb.h"
31
32/* Copy CHUNKSIZE bytes (or until EOF if CHUNKSIZE equals -1) from SRC_FILE
33 * to DST_FILE.  */
34extern int copy_file_chunk(FILE *src_file, FILE *dst_file, unsigned long long chunksize)
35{
36	size_t nread, nwritten, size;
37	char buffer[BUFSIZ];
38
39	while (chunksize != 0) {
40		if (chunksize > BUFSIZ)
41			size = BUFSIZ;
42		else
43			size = chunksize;
44
45		nread = fread (buffer, 1, size, src_file);
46
47		if (nread != size && ferror (src_file)) {
48			perror_msg ("read");
49			return -1;
50		} else if (nread == 0) {
51			if (chunksize != -1) {
52				error_msg ("Unable to read all data");
53				return -1;
54			}
55
56			return 0;
57		}
58
59		nwritten = fwrite (buffer, 1, nread, dst_file);
60
61		if (nwritten != nread) {
62			if (ferror (dst_file))
63				perror_msg ("write");
64			else
65				error_msg ("Unable to write all data");
66			return -1;
67		}
68
69		if (chunksize != -1)
70			chunksize -= nwritten;
71	}
72
73	return 0;
74}
75