1 /* $OpenBSD: uucplock.c,v 1.6 1998/07/13 02:11:44 millert Exp $ */
2 /* $NetBSD: uucplock.c,v 1.7 1997/02/11 09:24:08 mrg Exp $ */
5 * Copyright (c) 1988, 1993
6 * The Regents of the University of California. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
42 static char sccsid[] = "@(#)uucplock.c 8.1 (Berkeley) 6/6/93";
43 static char rcsid[] = "$OpenBSD: uucplock.c,v 1.6 1998/07/13 02:11:44 millert Exp $";
47 #include <sys/types.h>
49 #include <sys/dirent.h>
56 #include "pathnames.h"
59 * uucp style locking routines
69 char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN];
73 (void)snprintf(tbuf, sizeof tbuf, _PATH_LOCKDIRNAME, ttyname);
74 fd = open(tbuf, O_RDWR|O_CREAT|O_EXCL, 0660);
77 * file is already locked
78 * check to see if the process holding the lock still exists
80 fd = open(tbuf, O_RDWR, 0);
83 fprintf(stderr, "Can't open lock file.\n");
86 len = read(fd, text_pid, sizeof(text_pid)-1);
90 fprintf(stderr, "Can't read lock file.\n");
96 if (kill(pid, 0) == 0 || errno != ESRCH) {
97 (void)close(fd); /* process is still running */
101 * The process that locked the file isn't running, so
102 * we'll lock it ourselves
104 fprintf(stderr, "Stale lock on %s PID=%d... overriding.\n",
106 if (lseek(fd, (off_t)0, SEEK_SET) < 0) {
109 fprintf(stderr, "Can't seek lock file.\n");
112 /* fall out and finish the locking process */
115 (void)sprintf(text_pid, "%10d\n", pid);
116 len = strlen(text_pid);
117 if (write(fd, text_pid, len) != len) {
120 perror("lock write");
131 char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN];
133 (void)snprintf(tbuf, sizeof tbuf, _PATH_LOCKDIRNAME, ttyname);
134 return(unlink(tbuf));