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Use ASCII lock instead of BINARY one.

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This commit is contained in:
Andrey A. Chernov 1994-12-19 01:57:17 +00:00
parent 338bca2c5e
commit 11c5d06117
1 changed files with 15 additions and 22 deletions
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37
usr.bin/tip/uucplock.c
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@ -39,6 +39,8 @@ static char sccsid[] = "@(#)uucplock.c 8.1 (Berkeley) 6/6/93";
#include <sys/file.h>
#include <sys/dir.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include "pathnames.h"
/*
@ -50,52 +52,43 @@ static char sccsid[] = "@(#)uucplock.c 8.1 (Berkeley) 6/6/93";
uu_lock(ttyname)
char *ttyname;
{
extern int errno;
int fd, pid;
char tbuf[sizeof(_PATH_LOCKDIRNAME) + MAXNAMLEN];
off_t lseek();
FILE *ff;
(void)sprintf(tbuf, _PATH_LOCKDIRNAME, ttyname);
fd = open(tbuf, O_RDWR|O_CREAT|O_EXCL, 0660);
if (fd < 0) {
fd = open(tbuf, O_WRONLY|O_CREAT|O_EXCL, 0644);
if (fd >= 0)
ff = fdopen(fd, "w");
if (fd < 0 || ff == NULL) {
/*
* file is already locked
* check to see if the process holding the lock still exists
*/
fd = open(tbuf, O_RDWR, 0);
if (fd < 0) {
ff = fopen(tbuf, "r+");
if (ff == NULL) {
perror("lock open");
return(-1);
}
if (read(fd, &pid, sizeof(pid)) != sizeof(pid)) {
(void)close(fd);
if (fscanf(ff, "%10d\n", &pid) != 1) {
perror("lock read");
(void)fclose(ff);
return(-1);
}
if (kill(pid, 0) == 0 || errno != ESRCH) {
(void)close(fd); /* process is still running */
(void)fclose(ff); /* process is still running */
return(-1);
}
/*
* The process that locked the file isn't running, so
* we'll lock it ourselves
*/
if (lseek(fd, 0L, L_SET) < 0) {
(void)close(fd);
perror("lock lseek");
return(-1);
}
rewind(ff);
/* fall out and finish the locking process */
}
pid = getpid();
if (write(fd, (char *)&pid, sizeof(pid)) != sizeof(pid)) {
(void)close(fd);
(void)unlink(tbuf);
perror("lock write");
return(-1);
}
(void)close(fd);
(void)fprintf(ff, "%10d\n", getpid());
(void)fclose(ff);
return(0);
}