xref: /netbsd-src/lib/libc/sys/pwrite.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: pwrite.c,v 1.7 2003/08/07 16:44:04 agc Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: pwrite.c,v 1.7 2003/08/07 16:44:04 agc Exp $");
35 #endif /* LIBC_SCCS and not lint */
36 
37 #include "namespace.h"
38 #include <sys/types.h>
39 #include <sys/syscall.h>
40 #include <unistd.h>
41 
42 #ifdef __weak_alias
43 __weak_alias(pwrite,_sys_pwrite)
44 __weak_alias(_pwrite,_sys_pwrite)
45 #endif
46 
47 ssize_t	 _sys_pwrite __P((int, const void *, size_t, off_t));
48 
49 /*
50  * This function provides 64-bit offset padding that
51  * is not supplied by GCC 1.X but is supplied by GCC 2.X.
52  */
53 ssize_t
54 _sys_pwrite(fd, buf, nbyte, offset)
55 	int fd;
56 	const void *buf;
57 	size_t nbyte;
58 	off_t offset;
59 {
60 	quad_t q;
61 	int rv;
62 
63 	q = __syscall((quad_t)SYS_pwrite, fd, buf, nbyte, 0, offset);
64 	if (/* LINTED constant */ sizeof (quad_t) == sizeof (register_t) ||
65 	    /* LINTED constant */ BYTE_ORDER == LITTLE_ENDIAN)
66 		rv = (int)q;
67 	else
68 		rv = (int)((u_quad_t)q >> 32);
69 	return rv;
70 }
71