Change value because st.st_mtime might not be set, see above

[user/henk/code/snooze.git] / snooze.c

diff --git a/snooze.c b/snooze.c
index 9a3381a06144667379d2ab2c208fa478ff16dcfb..ed929c77e8c38789a0a6ea11a316b7eb0b73e1e4 100644 (file)
--- a/snooze.c
+++ b/snooze.c
@@ -28,6 +28,7 @@ static int nflag, vflag;
 
 static int timewait = -1;
 static int randdelay = 0;
+static int jitter = 0;
 static char *timefile;
 
 static sig_atomic_t alarm_rang = 0;
@@ -99,7 +100,7 @@ parse(char *expr, char *buf, long bufsiz, int offset)
        while (*s) {
                switch (*s) {
                case '0': case '1': case '2': case '3': case '4':
-                case '5': case '6': case '7': case '8': case '9':
+               case '5': case '6': case '7': case '8': case '9':
                        n = parse_int(&s, -offset, bufsiz);
                        buf[n+offset] = '*';
                        break;
@@ -120,7 +121,7 @@ parse(char *expr, char *buf, long bufsiz, int offset)
                        for (i = n0; i < bufsiz; i += n)
                                buf[i+offset] = '*';
                        break;
-                case ',':
+               case ',':
                        s++;
                        n = 0;
                        break;
@@ -140,9 +141,9 @@ parse(char *expr, char *buf, long bufsiz, int offset)
 }
 
 char weekday[8] = {0};
-char dayofmonth[31] = {0};
-char month[12] = {0};
-char dayofyear[366] = {0};
+char dayofmonth[32] = {0};
+char month[13] = {0};
+char dayofyear[367] = {0};
 char weekofyear[54] = {0};
 char hour[24] = {0};
 char minute[60] = {0};
@@ -168,11 +169,12 @@ find_next(time_t from)
        tm = localtime(&t);
 
 next_day:
-       while (!(weekday[tm->tm_wday] == '*'
-           && dayofmonth[tm->tm_mday-1] == '*'
-           && month[tm->tm_mon] == '*'
-           && weekofyear[isoweek(tm)] == '*'
-           && dayofyear[tm->tm_yday] == '*')) {
+       while (!(
+           weekday[tm->tm_wday] == '*' &&
+           dayofmonth[tm->tm_mday-1] == '*' &&
+           month[tm->tm_mon] == '*' &&
+           weekofyear[isoweek(tm)-1] == '*' &&
+           dayofyear[tm->tm_yday] == '*')) {
                if (month[tm->tm_mon] != '*') {
                        // if month is not good, step month
                        tm->tm_mon++;
@@ -181,20 +183,24 @@ next_day:
                        tm->tm_mday++;
                }
 
+               tm->tm_isdst = -1;
                tm->tm_sec = 0;
                tm->tm_min = 0;
                tm->tm_hour = 0;
 
                t = mktime(tm);
+               tm->tm_isdst = -1;
+
                if (t > from+(366*24*60*60))  // no result within a year
                        return -1;
        }
 
        int y = tm->tm_yday;  // save yday
 
-       while (!(hour[tm->tm_hour] == '*'
-           && minute[tm->tm_min] == '*'
-           && second[tm->tm_sec] == '*')) {
+       while (!(
+           hour[tm->tm_hour] == '*' &&
+           minute[tm->tm_min] == '*' &&
+           second[tm->tm_sec] == '*')) {
                if (hour[tm->tm_hour] != '*') {
                        tm->tm_hour++;
                        tm->tm_min = 0;
@@ -209,7 +215,15 @@ next_day:
                if (tm->tm_yday != y)  // hit a different day, retry...
                        goto next_day;
        }
-           
+
+       if (jitter && !nflag) {
+               long delay;
+               delay = lrand48() % jitter;
+               if (vflag)
+                       printf("adding %lds for jitter.\n", delay);
+               t += delay;
+       }
+
        return t;
 }
 
@@ -221,7 +235,8 @@ isotime(const struct tm *tm)
        return isobuf;
 }
 
-int main(int argc, char *argv[])
+int
+main(int argc, char *argv[])
 {
        int c;
        time_t t;
@@ -238,8 +253,10 @@ int main(int argc, char *argv[])
        minute[0] = '*';
        second[0] = '*';
 
-       while ((c = getopt(argc, argv, "+D:W:H:M:S:T:R:d:m:ns:t:vw:")) != -1)
-                switch(c) {
+       setvbuf(stdout, 0, _IOLBF, 0);
+
+       while ((c = getopt(argc, argv, "+D:W:H:M:S:T:R:J:d:m:ns:t:vw:")) != -1)
+               switch (c) {
                case 'D': parse(optarg, dayofyear, sizeof dayofyear, -1); break;
                case 'W': parse(optarg, weekofyear, sizeof weekofyear, -1); break;
                case 'H': parse(optarg, hour, sizeof hour, 0); break;
@@ -249,7 +266,7 @@ int main(int argc, char *argv[])
                case 'm': parse(optarg, month, sizeof month, -1); break;
                case 'w': parse(optarg, weekday, sizeof weekday, 0);
                        // special case: sunday is both 0 and 7.
-                       if (weekday[7] == '*') 
+                       if (weekday[7] == '*')
                                weekday[0] = '*';
                        break;
                case 'n': nflag++; break;
@@ -258,14 +275,15 @@ int main(int argc, char *argv[])
                case 'T': timewait = parse_dur(optarg); break;
                case 't': timefile = optarg; break;
                case 'R': randdelay = parse_dur(optarg); break;
+               case 'J': jitter = parse_dur(optarg); break;
                default:
-                        fprintf(stderr, "Usage: %s [-nv] [-t timefile] [-T timewait] [-R randdelay] [-s slack]\n"
+                       fprintf(stderr, "Usage: %s [-nv] [-t timefile] [-T timewait] [-R randdelay] [-J jitter] [-s slack]\n"
                            "  [-d mday] [-m mon] [-w wday] [-D yday] [-W yweek] [-H hour] [-M min] [-S sec] COMMAND...\n"
                            "Timespec: exact: 1,3,5\n"
                            "          range: 1-7\n"
                            "          every n-th: /10\n", argv[0]);
-                        exit(2);
-                }
+                       exit(2);
+               }
 
        time_t start = now + 1;
 
@@ -283,23 +301,16 @@ int main(int argc, char *argv[])
                                t = find_next(t + 1);
                        start = t;
                } else {
-                       if (t + timewait > start)
-                               start = st.st_mtime + timewait;
+                       if (t + timewait > start - slack)
+                               start = t + timewait;
                }
        }
 
+       srand48(getpid() ^ start);
+
        if (randdelay) {
                long delay;
-#ifdef __linux__
-               long rnd = getauxval(AT_RANDOM);
-               if (rnd > 0)
-                       delay = rnd % randdelay;
-               else
-#endif
-               {
-                       srand48(getpid() ^ start);
-                       delay = lrand48() % randdelay;
-               }
+               delay = lrand48() % randdelay;
                if (vflag)
                        printf("randomly delaying by %lds.\n", delay);
                start += delay;
@@ -318,13 +329,18 @@ int main(int argc, char *argv[])
                        char weekstr[4];
                        struct tm *tm = localtime(&t);
                        strftime(weekstr, sizeof weekstr, "%a", tm);
-                       printf("%s %s %2ldd%3ldh%3ldm%3lds\n",
+                       printf("%s %s %2ldd%3ldh%3ldm%3lds ",
                            isotime(tm),
                            weekstr,
                            ((t - now) / (60*60*24)),
                            ((t - now) / (60*60)) % 24,
                            ((t - now) / 60) % 60,
                            (t - now) % 60);
+                       if(jitter) {
+                               printf("(plus up to %ds for jitter)\n", jitter);
+                       } else {
+                               printf("\n");
+                       }
                        t = find_next(t + 1);
                        if (t < 0) {
                                fprintf(stderr,
@@ -376,16 +392,16 @@ int main(int argc, char *argv[])
                }
        }
 
-       // no command to run, the outside script can go on
-       if (argc == optind)
-               return 0;
-
        if (vflag) {
                now = time(0);
                tm = localtime(&now);
                printf("Starting execution at %s\n", isotime(tm));
        }
 
+       // no command to run, the outside script can go on
+       if (argc == optind)
+               return 0;
+
        execvp(argv[optind], argv+optind);
        perror("execvp");
        return 255;