fwrite.c revision 302408 
1/*
2 * Copyright (c) 2000-2001 Proofpoint, Inc. and its suppliers.
3 *      All rights reserved.
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * By using this file, you agree to the terms and conditions set
11 * forth in the LICENSE file which can be found at the top level of
12 * the sendmail distribution.
13 */
14
15#include <sm/gen.h>
16SM_RCSID("@(#)$Id: fwrite.c,v 1.25 2013-11-22 20:51:43 ca Exp $")
17#include <errno.h>
18#include <sm/io.h>
19#include <sm/assert.h>
20#include "local.h"
21#include "fvwrite.h"
22
23/*
24**  SM_IO_WRITE -- write to a file pointer
25**
26**	Parameters:
27**		fp -- file pointer writing to
28**		timeout -- time to complete the write
29**		buf -- location of data to be written
30**		size -- number of bytes to be written
31**
32**	Result:
33**		Failure: returns 0 _and_ sets errno
34**		Success: returns >=0 with errno unchanged, where the
35**			number returned is the number of bytes written.
36*/
37
38size_t
39sm_io_write(fp, timeout, buf, size)
40	SM_FILE_T *fp;
41	int timeout;
42	const void *buf;
43	size_t size;
44{
45	struct sm_uio uio;
46	struct sm_iov iov;
47
48	SM_REQUIRE_ISA(fp, SmFileMagic);
49
50	if (fp->f_write == NULL)
51	{
52		errno = ENODEV;
53		return 0;
54	}
55
56	iov.iov_base = (void *) buf;
57	uio.uio_resid = iov.iov_len = size;
58	uio.uio_iov = &iov;
59	uio.uio_iovcnt = 1;
60
61	/* The usual case is success (sm_fvwrite returns 0) */
62	if (sm_fvwrite(fp, timeout, &uio) == 0)
63		return size;
64
65	/* else return number of bytes actually written */
66	return size - uio.uio_resid;
67}
68