int
main(int ac, char **av)
{
int x;
char *file = (char *)NULL;
pid_t pid = 0;
int uucpstyle = FALSE; /* indicating UUCP style locks */
int only_check = TRUE; /* don't make a lock */
Pname = ((Pname = strrchr(av[0], '/')) ? Pname + 1 : av[0]);
for(x = 1; x < ac; x++) {
if (av[x][0] == '-') {
switch(av[x][1]) {
case 'u':
uucpstyle = TRUE;
break;
case 'd':
Debug = TRUE;
break;
case 'p':
if (strlen(av[x]) > 2) {
pid = atoi(&av[x][2]);
} else {
if (++x >= ac) {
bad_usage();
}
pid = atoi(av[x]);
}
only_check = FALSE; /* wants one */
break;
case 'f':
if (strlen(av[x]) > 2) {
file = &av[x][2];
} else {
if (++x >= ac) {
bad_usage();
}
file = av[x];
}
break;
default:
bad_usage();
}
}
}
if (file == (char *)NULL || (!only_check && pid <= 0)) {
bad_usage();
}
if (only_check) {
exit(cklock(file, uucpstyle) ? LOCK_GOOD : LOCK_BAD);
}
exit(mklock(file, pid, uucpstyle) ? LOCK_SET : LOCK_FAIL);
}
/*
* Open a file, locking using the lock types specified. Returns EAGAIN if lock
* failed.
*/
int
openlock(const char *path, int flags, u_int locks)
{
int fd, saved_errno;
if (mklock(locks, path) != 0)
return (-1);
if ((fd = open(path, flags, 0)) == -1)
goto error;
if (lockfd(locks, fd) != 0)
goto error;
return (fd);
error:
saved_errno = errno;
close(fd);
rmlock(locks, path);
errno = saved_errno;
return (-1);
}
/* Create a locked file. */
int
createlock(
const char *path, int flags, uid_t uid, gid_t gid, mode_t mode, u_int locks)
{
int fd, saved_errno;
if (mklock(locks, path) != 0)
return (-1);
if ((fd = xcreate(path, flags, uid, gid, mode)) == -1)
goto error;
if (lockfd(locks, fd) != 0)
goto error;
return (fd);
error:
saved_errno = errno;
close(fd);
rmlock(locks, path);
errno = saved_errno;
return (-1);
}
static int
mklock(char *file)
{
int fd, try;
Dir *dir;
fd = openlock(file);
if (fd >= 0) {
/* make it a lock file if it wasn't */
dir = dirfstat(fd);
if (dir == nil)
error("%s vanished: %r", file);
dir->mode |= DMEXCL;
dir->qid.type |= QTEXCL;
dirfwstat(fd, dir);
free(dir);
/* reopen in case it wasn't a lock file at last open */
close(fd);
}
for (try = 0; try < 65 && (fd = openlock(file)) < 0; try++)
sleep(10*1000);
return fd;
}
void
main(int argc, char *argv[])
{
Job *j;
Tm tm;
Time t;
ulong now, last; /* in seconds */
int i, lock;
debug = 0;
ARGBEGIN{
case 'c':
createuser();
exits(0);
case 'd':
debug = 1;
break;
default:
usage();
}ARGEND
if(debug){
readalljobs();
printjobs();
exits(0);
}
initcap(); /* do this early, before cpurc removes it */
switch(fork()){
case -1:
fatal("can't fork: %r");
case 0:
break;
default:
exits(0);
}
/*
* it can take a few minutes before the file server notices that
* we've rebooted and gives up the lock.
*/
lock = mklock("/cron/lock");
if (lock < 0)
fatal("cron already running: %r");
argv0 = "cron";
srand(getpid()*time(0));
last = time(0);
for(;;){
readalljobs();
/*
* the system's notion of time may have jumped forward or
* backward an arbitrary amount since the last call to time().
*/
now = time(0);
/*
* if time has jumped backward, just note it and adapt.
* if time has jumped forward more than a day,
* just execute one day's jobs.
*/
if (now < last) {
clog("time went backward");
last = now;
} else if (now - last > Day) {
clog("time advanced more than a day");
last = now - Day;
}
now = minute(now);
for(last = minute(last); last <= now; last += Minute){
tm = *localtime(last);
t.min = 1ULL << tm.min;
t.hour = 1 << tm.hour;
t.wday = 1 << tm.wday;
t.mday = 1 << tm.mday;
t.mon = 1 << (tm.mon + 1);
for(i = 0; i < nuser; i++)
for(j = users[i].jobs; j; j = j->next)
if(j->time.min & t.min
&& j->time.hour & t.hour
&& j->time.wday & t.wday
&& j->time.mday & t.mday
&& j->time.mon & t.mon)
rexec(&users[i], j);
}
seek(lock, 0, 0);
write(lock, "x", 1); /* keep the lock alive */
/*
* if we're not at next minute yet, sleep until a second past
* (to allow for sleep intervals being approximate),
* which synchronises with minute roll-over as a side-effect.
*/
sleepuntil(now + Minute + 1);
}
/* not reached */
}
/*
* get next conversation sequence number
* rmtname -> name of remote system
* returns:
* 0 -> no entery
* 1 -> 0 sequence number
*/
int
gnxseq(char *rmtname)
{
register FILE *fp0, *fp1;
register struct tm *tp;
int count = 0, ct, ret;
char buf[BUFSIZ], name[NAMESIZE];
time_t clock;
if (access(SQFILE, 0) != 0)
return (0);
{
int i;
for (i = 0; i < 5; i++)
if ((ret = mklock(SQLOCK)) == SUCCESS)
break;
sleep(5);
}
if (ret != SUCCESS) {
logent("CAN'T LOCK", SQLOCK);
DEBUG(4, "can't lock %s\n", SQLOCK);
return (0);
}
if ((fp0 = fopen(SQFILE, "r")) == NULL)
return (0);
if ((fp1 = fopen(SQTMP, "w")) == NULL) {
fclose(fp0);
return (0);
}
chmod(SQTMP, DFILEMODE);
while (fgets(buf, BUFSIZ, fp0) != NULL) {
ret = sscanf(buf, "%s%d", name, &ct);
if (ret < 2)
ct = 0;
name[7] = '\0';
if (ct > 9998)
ct = 0;
if (strncmp(rmtname, name, SYSNSIZE) != SAME) {
fputs(buf, fp1);
continue;
}
/*
* found name
*/
count = ++ct;
time(&clock);
tp = localtime(&clock);
fprintf(fp1, "%s %d %d/%d-%d:%2.2d\n", name, ct,
tp->tm_mon + 1, tp->tm_mday, tp->tm_hour,
tp->tm_min);
/*
* write should be checked
*/
while (fgets(buf, BUFSIZ, fp0) != NULL)
fputs(buf, fp1);
}
fclose(fp0);
fclose(fp1);
if (count == 0) {
rmlock(SQLOCK);
unlink(SQTMP);
}
return (count);
}