xref: /titanic_41/usr/src/cmd/sendmail/libsm/fwrite.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * Copyright (c) 2000-2001 Sendmail, 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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
16 
17 #include <sm/gen.h>
18 SM_RCSID("@(#)$Id: fwrite.c,v 1.22 2001/04/03 01:46:40 ca Exp $")
19 #include <errno.h>
20 #include <sm/io.h>
21 #include <sm/assert.h>
22 #include "local.h"
23 #include "fvwrite.h"
24 
25 /*
26 **  SM_IO_WRITE -- write to a file pointer
27 **
28 **	Parameters:
29 **		fp -- file pointer writing to
30 **		timeout -- time to complete the write
31 **		buf -- location of data to be written
32 **		size -- number of bytes to be written
33 **
34 **	Result:
35 **		Failure: returns 0 _and_ sets errno
36 **		Success: returns >=0 with errno unchanged, where the
37 **			number returned is the number of bytes written.
38 */
39 
40 size_t
41 sm_io_write(fp, timeout, buf, size)
42 	SM_FILE_T *fp;
43 	int timeout;
44 	const void *buf;
45 	size_t size;
46 {
47 	struct sm_uio uio;
48 	struct sm_iov iov;
49 
50 	SM_REQUIRE_ISA(fp, SmFileMagic);
51 
52 	if (fp->f_write == NULL)
53 	{
54 		errno = ENODEV;
55 		return 0;
56 	}
57 
58 	iov.iov_base = (void *) buf;
59 	uio.uio_resid = iov.iov_len = size;
60 	uio.uio_iov = &iov;
61 	uio.uio_iovcnt = 1;
62 
63 	/* The usual case is success (sm_fvwrite returns 0) */
64 	if (sm_fvwrite(fp, timeout, &uio) == 0)
65 		return size;
66 
67 	/* else return number of bytes actually written */
68 	return size - uio.uio_resid;
69 }
70