xref: /onnv-gate/usr/src/lib/libbc/libc/sys/common/ftruncate.c (revision 3224:c0c9287a0eec)
10Sstevel@tonic-gate /*
20Sstevel@tonic-gate  * CDDL HEADER START
30Sstevel@tonic-gate  *
40Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*3224Sraf  * Common Development and Distribution License (the "License").
6*3224Sraf  * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate  *
80Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate  * See the License for the specific language governing permissions
110Sstevel@tonic-gate  * and limitations under the License.
120Sstevel@tonic-gate  *
130Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate  *
190Sstevel@tonic-gate  * CDDL HEADER END
200Sstevel@tonic-gate  */
21*3224Sraf 
220Sstevel@tonic-gate /*
23*3224Sraf  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24*3224Sraf  * Use is subject to license terms.
250Sstevel@tonic-gate  */
260Sstevel@tonic-gate 
270Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
280Sstevel@tonic-gate 
29*3224Sraf #include <sys/syscall.h>
300Sstevel@tonic-gate #include <sys/types.h>
310Sstevel@tonic-gate 
320Sstevel@tonic-gate /* The following are from SVR4 sys/fcntl.h */
330Sstevel@tonic-gate 
34*3224Sraf #define	F_FREESP	11	/* Free file space */
35*3224Sraf #define	F_WRLCK		02	/* Write Lock */
360Sstevel@tonic-gate 
370Sstevel@tonic-gate /* lock structure from SVR4. */
380Sstevel@tonic-gate struct fl {
390Sstevel@tonic-gate 	short l_type;
400Sstevel@tonic-gate 	short l_whence;
410Sstevel@tonic-gate 	off_t l_start;
420Sstevel@tonic-gate 	off_t l_len;
430Sstevel@tonic-gate 	long  l_sysid;
440Sstevel@tonic-gate 	pid_t l_pid;
450Sstevel@tonic-gate 	long  pad[4];
460Sstevel@tonic-gate };
470Sstevel@tonic-gate 
48*3224Sraf int
ftruncate(int fd,off_t length)49*3224Sraf ftruncate(int fd, off_t length)
500Sstevel@tonic-gate {
510Sstevel@tonic-gate 
520Sstevel@tonic-gate 	struct fl lck;
530Sstevel@tonic-gate 
540Sstevel@tonic-gate 	lck.l_whence = 0;	/* offset l_start from beginning of file */
55*3224Sraf 	lck.l_start = length;
560Sstevel@tonic-gate 	lck.l_type = F_WRLCK;	/* setting a write lock */
570Sstevel@tonic-gate 	lck.l_len = 0L;
580Sstevel@tonic-gate 
590Sstevel@tonic-gate 	if (_syscall(SYS_fcntl, fd, F_FREESP, (int)&lck) == -1)
600Sstevel@tonic-gate 		return (-1);
61*3224Sraf 	else
620Sstevel@tonic-gate 		return (0);
63*3224Sraf }
64