xref: /titanic_44/usr/src/lib/libbc/libc/sys/common/ftruncate.c (revision b5a2d8455dfa3190fc977c4bec53e91c99012767)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/syscall.h>
30 #include <sys/types.h>
31 
32 /* The following are from SVR4 sys/fcntl.h */
33 
34 #define	F_FREESP	11	/* Free file space */
35 #define	F_WRLCK		02	/* Write Lock */
36 
37 /* lock structure from SVR4. */
38 struct fl {
39 	short l_type;
40 	short l_whence;
41 	off_t l_start;
42 	off_t l_len;
43 	long  l_sysid;
44 	pid_t l_pid;
45 	long  pad[4];
46 };
47 
48 int
49 ftruncate(int fd, off_t length)
50 {
51 
52 	struct fl lck;
53 
54 	lck.l_whence = 0;	/* offset l_start from beginning of file */
55 	lck.l_start = length;
56 	lck.l_type = F_WRLCK;	/* setting a write lock */
57 	lck.l_len = 0L;
58 
59 	if (_syscall(SYS_fcntl, fd, F_FREESP, (int)&lck) == -1)
60 		return (-1);
61 	else
62 		return (0);
63 }
64