1/* vi: set sw=4 ts=4: */
2/*
3 * Utility routines.
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include "libbb.h"
11
12/*
13 * Write all of the supplied buffer out to a file.
14 * This does multiple writes as necessary.
15 * Returns the amount written, or -1 on an error.
16 */
17ssize_t FAST_FUNC full_write(int fd, const void *buf, size_t len)
18{
19	ssize_t cc;
20	ssize_t total;
21
22	total = 0;
23
24	while (len) {
25		cc = safe_write(fd, buf, len);
26
27		if (cc < 0) {
28			if (total) {
29				/* we already wrote some! */
30				/* user can do another write to know the error code */
31				return total;
32			}
33			return cc;	/* write() returns -1 on failure. */
34		}
35
36		total += cc;
37		buf = ((const char *)buf) + cc;
38		len -= cc;
39	}
40
41	return total;
42}
43