1 /* Copyright 1988,1990,1993,1994 by Paul Vixie
4 * Distribute freely, except: don't remove my name from the source or
5 * documentation (don't take credit for my work), mark your changes (don't
6 * get me blamed for your possible bugs), don't alter or remove this
7 * notice. May be sold if buildable source is provided to buyer. No
8 * warrantee of any kind, express or implied, is included with this
9 * software; use at your own risk, responsibility for damages (if any) to
10 * anyone resulting from the use of this software rests entirely with the
13 * Send bug reports, bug fixes, enhancements, requests, flames, etc., and
14 * I'll try to keep a version up to date. I can be reached as follows:
15 * Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul
18 #if !defined(lint) && !defined(LINT)
19 static const char rcsid[] =
27 #include <sys/signal.h>
29 # include <sys/time.h>
35 static void usage __P((void)),
36 run_reboot_jobs __P((cron_db *)),
37 cron_tick __P((cron_db *)),
38 cron_sync __P((void)),
39 cron_sleep __P((cron_db *)),
40 cron_clean __P((cron_db *)),
42 sigchld_handler __P((int)),
44 sighup_handler __P((int)),
45 parse_args __P((int c, char *v[]));
47 static time_t last_time = 0;
48 static int dst_enabled = 0;
55 fprintf(stderr, "usage: cron [-j jitter] [-J rootjitter] "
56 "[-s] [-o] [-x debugflag[,...]]\n");
57 fprintf(stderr, "\ndebugflags: ");
59 for(dflags = DebugFlagNames; *dflags; dflags++) {
60 fprintf(stderr, "%s ", *dflags);
62 fprintf(stderr, "\n");
70 char pidfile[MAX_FNAME];
71 char buf[MAX_TEMPSTR];
74 (void) snprintf(pidfile, sizeof(pidfile), PIDFILE, PIDDIR);
75 pfh = pidfile_open(pidfile, 0600, &otherpid);
77 if (errno == EEXIST) {
78 snprintf(buf, sizeof(buf),
79 "cron already running, pid: %d", otherpid);
81 snprintf(buf, sizeof(buf),
82 "can't open or create %s: %s", pidfile,
85 log_it("CRON", getpid(), "DEATH", buf);
86 errx(ERROR_EXIT, "%s", buf);
97 ProgramName = argv[0];
104 parse_args(argc, argv);
107 (void) signal(SIGCHLD, sigchld_handler);
109 (void) signal(SIGCLD, SIG_IGN);
111 (void) signal(SIGHUP, sighup_handler);
118 setenv("PATH", _PATH_DEFPATH, 1);
121 /* if there are no debug flags turned on, fork as a daemon should.
128 (void) fprintf(stderr, "[%d] cron started\n", getpid());
130 if (daemon(1, 0) == -1) {
132 log_it("CRON",getpid(),"DEATH","can't become daemon");
138 database.head = NULL;
139 database.tail = NULL;
140 database.mtime = (time_t) 0;
141 load_database(&database);
142 run_reboot_jobs(&database);
146 /* if (!(DebugFlags & DTEST)) */
147 # endif /*DEBUGGING*/
148 cron_sleep(&database);
150 load_database(&database);
154 cron_tick(&database);
170 for (u = db->head; u != NULL; u = u->next) {
171 for (e = u->crontab; e != NULL; e = e->next) {
172 if (e->flags & WHEN_REBOOT) {
177 (void) job_runqueue();
185 static struct tm lasttm;
186 static time_t diff = 0, /* time difference in seconds from the last offset change */
187 difflimit = 0; /* end point for the time zone correction */
188 struct tm otztm; /* time in the old time zone */
189 int otzminute, otzhour, otzdom, otzmonth, otzdow;
190 register struct tm *tm = localtime(&TargetTime);
191 register int minute, hour, dom, month, dow;
195 /* make 0-based values out of these so we can use them as indicies
197 minute = tm->tm_min -FIRST_MINUTE;
198 hour = tm->tm_hour -FIRST_HOUR;
199 dom = tm->tm_mday -FIRST_DOM;
200 month = tm->tm_mon +1 /* 0..11 -> 1..12 */ -FIRST_MONTH;
201 dow = tm->tm_wday -FIRST_DOW;
203 Debug(DSCH, ("[%d] tick(%d,%d,%d,%d,%d)\n",
204 getpid(), minute, hour, dom, month, dow))
206 if (dst_enabled && last_time != 0
207 && TargetTime > last_time /* exclude stepping back */
208 && tm->tm_gmtoff != lasttm.tm_gmtoff ) {
210 diff = tm->tm_gmtoff - lasttm.tm_gmtoff;
212 if ( diff > 0 ) { /* ST->DST */
213 /* mark jobs for an earlier run */
214 difflimit = TargetTime + diff;
215 for (u = db->head; u != NULL; u = u->next) {
216 for (e = u->crontab; e != NULL; e = e->next) {
217 e->flags &= ~NOT_UNTIL;
218 if ( e->lastrun >= TargetTime )
220 /* not include the ends of hourly ranges */
221 if ( e->lastrun < TargetTime - 3600 )
227 } else { /* diff < 0 : DST->ST */
228 /* mark jobs for skipping */
229 difflimit = TargetTime - diff;
230 for (u = db->head; u != NULL; u = u->next) {
231 for (e = u->crontab; e != NULL; e = e->next) {
232 e->flags |= NOT_UNTIL;
240 /* if the time was reset of the end of special zone is reached */
241 if (last_time == 0 || TargetTime >= difflimit) {
242 /* disable the TZ switch checks */
245 for (u = db->head; u != NULL; u = u->next) {
246 for (e = u->crontab; e != NULL; e = e->next) {
247 e->flags &= ~(RUN_AT|NOT_UNTIL);
251 /* get the time in the old time zone */
252 time_t difftime = TargetTime + tm->tm_gmtoff - diff;
253 gmtime_r(&difftime, &otztm);
255 /* make 0-based values out of these so we can use them as indicies
257 otzminute = otztm.tm_min -FIRST_MINUTE;
258 otzhour = otztm.tm_hour -FIRST_HOUR;
259 otzdom = otztm.tm_mday -FIRST_DOM;
260 otzmonth = otztm.tm_mon +1 /* 0..11 -> 1..12 */ -FIRST_MONTH;
261 otzdow = otztm.tm_wday -FIRST_DOW;
265 /* the dom/dow situation is odd. '* * 1,15 * Sun' will run on the
266 * first and fifteenth AND every Sunday; '* * * * Sun' will run *only*
267 * on Sundays; '* * 1,15 * *' will run *only* the 1st and 15th. this
268 * is why we keep 'e->dow_star' and 'e->dom_star'. yes, it's bizarre.
269 * like many bizarre things, it's the standard.
271 for (u = db->head; u != NULL; u = u->next) {
272 for (e = u->crontab; e != NULL; e = e->next) {
273 Debug(DSCH|DEXT, ("user [%s:%d:%d:...] cmd=\"%s\"\n",
274 env_get("LOGNAME", e->envp),
275 e->uid, e->gid, e->cmd))
277 if ( diff != 0 && (e->flags & (RUN_AT|NOT_UNTIL)) ) {
278 if (bit_test(e->minute, otzminute)
279 && bit_test(e->hour, otzhour)
280 && bit_test(e->month, otzmonth)
281 && ( ((e->flags & DOM_STAR) || (e->flags & DOW_STAR))
282 ? (bit_test(e->dow,otzdow) && bit_test(e->dom,otzdom))
283 : (bit_test(e->dow,otzdow) || bit_test(e->dom,otzdom))
286 if ( e->flags & RUN_AT ) {
288 e->lastrun = TargetTime;
292 e->flags &= ~NOT_UNTIL;
293 } else if ( e->flags & NOT_UNTIL )
297 if (bit_test(e->minute, minute)
298 && bit_test(e->hour, hour)
299 && bit_test(e->month, month)
300 && ( ((e->flags & DOM_STAR) || (e->flags & DOW_STAR))
301 ? (bit_test(e->dow,dow) && bit_test(e->dom,dom))
302 : (bit_test(e->dow,dow) || bit_test(e->dom,dom))
306 e->lastrun = TargetTime;
312 last_time = TargetTime;
317 /* the task here is to figure out how long it's going to be until :00 of the
318 * following minute and initialize TargetTime to this value. TargetTime
319 * will subsequently slide 60 seconds at a time, with correction applied
320 * implicitly in cron_sleep(). it would be nice to let cron execute in
321 * the "current minute" before going to sleep, but by restarting cron you
322 * could then get it to execute a given minute's jobs more than once.
323 * instead we have the chance of missing a minute's jobs completely, but
324 * that's something sysadmin's know to expect what with crashing computers..
328 register struct tm *tm;
330 TargetTime = time((time_t*)0);
331 tm = localtime(&TargetTime);
332 TargetTime += (60 - tm->tm_sec);
340 int seconds_to_wait = 0;
343 * Loop until we reach the top of the next minute, sleep when possible.
347 seconds_to_wait = (int) (TargetTime - time((time_t*)0));
350 * If the seconds_to_wait value is insane, jump the cron
353 if (seconds_to_wait < -600 || seconds_to_wait > 600) {
359 Debug(DSCH, ("[%d] TargetTime=%ld, sec-to-wait=%d\n",
360 getpid(), (long)TargetTime, seconds_to_wait))
363 * If we've run out of wait time or there are no jobs left
367 if (seconds_to_wait <= 0)
369 if (job_runqueue() == 0) {
370 Debug(DSCH, ("[%d] sleeping for %d seconds\n",
371 getpid(), seconds_to_wait))
373 sleep(seconds_to_wait);
379 /* if the time was changed abruptly, clear the flags related
380 * to the daylight time switch handling to avoid strange effects
392 for (u = db->head; u != NULL; u = u->next) {
393 for (e = u->crontab; e != NULL; e = e->next) {
394 e->flags &= ~(RUN_AT|NOT_UNTIL);
401 sigchld_handler(int x)
408 pid = waitpid(-1, &waiter, WNOHANG);
410 pid = wait3(&waiter, WNOHANG, (struct rusage *)0);
415 ("[%d] sigchld...no children\n", getpid()))
419 ("[%d] sigchld...no dead kids\n", getpid()))
423 ("[%d] sigchld...pid #%d died, stat=%d\n",
424 getpid(), pid, WEXITSTATUS(waiter)))
428 #endif /*USE_SIGCHLD*/
432 sighup_handler(int x)
439 parse_args(argc, argv)
446 while ((argch = getopt(argc, argv, "j:J:osx:")) != -1) {
449 Jitter = strtoul(optarg, &endp, 10);
450 if (*optarg == '\0' || *endp != '\0' || Jitter > 60)
452 "bad value for jitter: %s", optarg);
455 RootJitter = strtoul(optarg, &endp, 10);
456 if (*optarg == '\0' || *endp != '\0' || RootJitter > 60)
458 "bad value for root jitter: %s", optarg);
467 if (!set_debug_flags(optarg))