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, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
23 /* All Rights Reserved */
24
25
26 /*
27 * University Copyright- Copyright (c) 1982, 1986, 1988
28 * The Regents of the University of California
29 * All Rights Reserved
30 *
31 * University Acknowledgment- Portions of this document are derived from
32 * software developed by the University of California, Berkeley, and its
33 * contributors.
34 */
35
36 /*
37 * lock a file pointer
38 */
39
40 #include <stdio.h>
41 #include <string.h>
42 #include <fcntl.h>
43
44 int
lock(FILE * fp,char * mode,int blk)45 lock(FILE *fp, char *mode, int blk)
46 {
47 struct flock l;
48
49 l.l_type = !strcmp(mode, "r") ? F_RDLCK : F_WRLCK;
50 l.l_whence = 0;
51 l.l_start = l.l_len = 0L;
52 return fcntl(fileno(fp), blk ? F_SETLKW : F_SETLK, &l);
53 }
54