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Diffstat (limited to 'usr.bin/tip/uucplock.c')
| -rw-r--r-- | usr.bin/tip/uucplock.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/usr.bin/tip/uucplock.c b/usr.bin/tip/uucplock.c new file mode 100644 index 00000000000..cf653acce9f --- /dev/null +++ b/usr.bin/tip/uucplock.c @@ -0,0 +1,127 @@ +/* $NetBSD: uucplock.c,v 1.6 1995/09/26 06:02:14 jtc Exp $ */ + +/* + * Copyright (c) 1988, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef lint +#if 0 +static char sccsid[] = "@(#)uucplock.c 8.1 (Berkeley) 6/6/93"; +#endif +static char rcsid[] = "$NetBSD: uucplock.c,v 1.6 1995/09/26 06:02:14 jtc Exp $"; +#endif /* not lint */ + +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/file.h> +#include <sys/dir.h> +#include <errno.h> +#include "pathnames.h" + +/* + * uucp style locking routines + * return: 0 - success + * -1 - failure + */ + +uu_lock(ttyname) + char *ttyname; +{ + int fd, pid; + char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN]; + char text_pid[81]; + int len; + + (void)sprintf(tbuf, _PATH_LOCKDIRNAME, ttyname); + fd = open(tbuf, O_RDWR|O_CREAT|O_EXCL, 0660); + if (fd < 0) { + /* + * file is already locked + * check to see if the process holding the lock still exists + */ + fd = open(tbuf, O_RDWR, 0); + if (fd < 0) { + perror(tbuf); + fprintf(stderr, "Can't open lock file.\n"); + return(-1); + } + len = read(fd, text_pid, sizeof(text_pid)-1); + if(len<=0) { + perror(tbuf); + (void)close(fd); + fprintf(stderr, "Can't read lock file.\n"); + return(-1); + } + text_pid[len] = 0; + pid = atol(text_pid); + + if (kill(pid, 0) == 0 || errno != ESRCH) { + (void)close(fd); /* process is still running */ + return(-1); + } + /* + * The process that locked the file isn't running, so + * we'll lock it ourselves + */ + fprintf(stderr, "Stale lock on %s PID=%d... overriding.\n", + ttyname, pid); + if (lseek(fd, (off_t)0, L_SET) < 0) { + perror(tbuf); + (void)close(fd); + fprintf(stderr, "Can't seek lock file.\n"); + return(-1); + } + /* fall out and finish the locking process */ + } + pid = getpid(); + sprintf(text_pid, "%10d\n", pid); + len = strlen(text_pid); + if (write(fd, text_pid, len) != len) { + (void)close(fd); + (void)unlink(tbuf); + perror("lock write"); + return(-1); + } + (void)close(fd); + return(0); +} + +uu_unlock(ttyname) + char *ttyname; +{ + char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN]; + + (void)sprintf(tbuf, _PATH_LOCKDIRNAME, ttyname); + return(unlink(tbuf)); +} |