2 * snooze - run a command at a particular time
4 * To the extent possible under law, Leah Neukirchen <leah@vuxu.org>
5 * has waived all copyright and related or neighboring rights to this work.
6 * http://creativecommons.org/publicdomain/zero/1.0/
10 #include <sys/types.h>
25 static long slack = 60;
26 #define SLEEP_PHASE 300
27 static int nflag, vflag;
29 static int timewait = -1;
30 static int randdelay = 0;
31 static char *timefile;
33 static sig_atomic_t alarm_rang = 0;
43 parse_int(char **s, size_t minn, size_t maxn)
49 n = strtol(*s, &end, 10);
54 if (n < (long)minn || n >= (long)maxn) {
55 fprintf(stderr, "number outside %zd <= n < %zd\n", minn, maxn);
69 n = strtol(s, &end, 10);
75 fprintf(stderr, "negative duration\n");
79 case 'm': n *= 60; break;
80 case 'h': n *= 60*60; break;
81 case 'd': n *= 24*60*60; break;
84 fprintf(stderr, "junk after duration: %s\n", end);
91 parse(char *expr, char *buf, long bufsiz, int offset)
94 long i, n = 0, n0 = 0;
96 memset(buf, ' ', bufsiz);
101 case '0': case '1': case '2': case '3': case '4':
102 case '5': case '6': case '7': case '8': case '9':
103 n = parse_int(&s, -offset, bufsiz);
109 n = parse_int(&s, -offset, bufsiz);
110 for (i = n0; i <= n; i++)
116 n = parse_int(&s, -offset, bufsiz);
119 for (i = n0; i < bufsiz; i += n)
129 for (i = 0; i < bufsiz; i++)
133 fprintf(stderr, "can't parse: %s %s\n", expr, s);
141 char weekday[8] = {0};
142 char dayofmonth[31] = {0};
143 char month[12] = {0};
144 char dayofyear[366] = {0};
145 char weekofyear[54] = {0};
147 char minute[60] = {0};
148 char second[61] = {0};
151 isoweek(struct tm *tm)
153 /* ugh, but easier than the correct formula... */
156 strftime(weekstr, sizeof weekstr, "%V", tm);
157 return parse_int(&w, 1, 54);
161 find_next(time_t from)
170 while (!(weekday[tm->tm_wday] == '*'
171 && dayofmonth[tm->tm_mday-1] == '*'
172 && month[tm->tm_mon] == '*'
173 && weekofyear[isoweek(tm)] == '*'
174 && dayofyear[tm->tm_yday] == '*')) {
175 if (month[tm->tm_mon] != '*') {
176 // if month is not good, step month
188 if (t > from+(366*24*60*60)) // no result within a year
192 int y = tm->tm_yday; // save yday
194 while (!(hour[tm->tm_hour] == '*'
195 && minute[tm->tm_min] == '*'
196 && second[tm->tm_sec] == '*')) {
197 if (hour[tm->tm_hour] != '*') {
201 } else if (minute[tm->tm_min] != '*') {
208 if (tm->tm_yday != y) // hit a different day, retry...
215 static char isobuf[25];
217 isotime(const struct tm *tm)
219 strftime(isobuf, sizeof isobuf, "%FT%T%z", tm);
223 int main(int argc, char *argv[])
227 time_t now = time(0);
230 /* default: every day at 00:00:00 */
231 memset(weekday, '*', sizeof weekday);
232 memset(dayofmonth, '*', sizeof dayofmonth);
233 memset(month, '*', sizeof month);
234 memset(dayofyear, '*', sizeof dayofyear);
235 memset(weekofyear, '*', sizeof weekofyear);
240 while ((c = getopt(argc, argv, "+D:W:H:M:S:T:R:d:m:ns:t:vw:")) != -1)
242 case 'D': parse(optarg, dayofyear, sizeof dayofyear, -1); break;
243 case 'W': parse(optarg, weekofyear, sizeof weekofyear, -1); break;
244 case 'H': parse(optarg, hour, sizeof hour, 0); break;
245 case 'M': parse(optarg, minute, sizeof minute, 0); break;
246 case 'S': parse(optarg, second, sizeof second, 0); break;
247 case 'd': parse(optarg, dayofmonth, sizeof dayofmonth, -1); break;
248 case 'm': parse(optarg, month, sizeof month, -1); break;
249 case 'w': parse(optarg, weekday, sizeof weekday, 0);
250 // special case: sunday is both 0 and 7.
251 if (weekday[7] == '*')
254 case 'n': nflag++; break;
255 case 'v': vflag++; break;
256 case 's': slack = parse_dur(optarg); break;
257 case 'T': timewait = parse_dur(optarg); break;
258 case 't': timefile = optarg; break;
259 case 'R': randdelay = parse_dur(optarg); break;
261 fprintf(stderr, "Usage: %s [-nv] [-t timefile] [-T timewait] [-R randdelay] [-s slack]\n"
262 " [-d mday] [-m mon] [-w wday] [-D yday] [-W yweek] [-H hour] [-M min] [-S sec] COMMAND...\n"
263 "Timespec: exact: 1,3,5\n"
265 " every n-th: /10\n", argv[0]);
269 time_t start = now + 1;
273 if (stat(timefile, &st) < 0) {
276 t = start - slack - 1 - timewait;
280 if (timewait == -1) {
281 while (t < start - slack)
282 t = find_next(t + 1);
285 if (t + timewait > start)
286 start = st.st_mtime + timewait;
293 long rnd = getauxval(AT_RANDOM);
295 delay = rnd % randdelay;
299 srand48(getpid() ^ start);
300 delay = lrand48() % randdelay;
303 printf("randomly delaying by %lds.\n", delay);
307 t = find_next(start);
309 fprintf(stderr, "no satisfying date found within a year.\n");
314 /* dry-run, just output the next 5 dates. */
316 for (i = 0; i < 5; i++) {
318 struct tm *tm = localtime(&t);
319 strftime(weekstr, sizeof weekstr, "%a", tm);
320 printf("%s %s %2ldd%3ldh%3ldm%3lds\n",
323 ((t - now) / (60*60*24)),
324 ((t - now) / (60*60)) % 24,
325 ((t - now) / 60) % 60,
327 t = find_next(t + 1);
330 "no satisfying date found within a year.\n");
337 struct tm *tm = localtime(&t);
339 printf("Snoozing until %s\n", isotime(tm));
341 // setup SIGALRM handler to force early execution
343 sa.sa_handler = &wakeup;
344 sa.sa_flags = SA_RESTART;
345 sigfillset(&sa.sa_mask);
346 sigaction(SIGALRM, &sa, NULL); // XXX error handling
348 while (!alarm_rang) {
353 printf("Time moved backwards, rescheduled for %s\n", isotime(tm));
357 if (now - t <= slack) // still about time
359 else { // reschedule to next event
361 printf("Missed execution at %s\n", isobuf);
362 t = find_next(now + 1);
365 printf("Snoozing until %s\n", isotime(tm));
368 // do some sleeping, but not more than SLEEP_PHASE
371 ts.tv_sec = t - now > SLEEP_PHASE ? SLEEP_PHASE : t - now;
374 // we just iterate again when this exits early
378 // no command to run, the outside script can go on
384 tm = localtime(&now);
385 printf("Starting execution at %s\n", isotime(tm));
388 execvp(argv[optind], argv+optind);