1 files changed, 128 insertions, 0 deletions
diff --git a/gcrond.c b/gcrond.c
new file mode 100644
index 0000000..0e28277
--- /dev/null
+++ b/gcrond.c
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: ISC */
+#include "gcrond.h"
+
+static crontab_t *jobs;
+static sig_atomic_t run = 1;
+static sig_atomic_t rescan = 1;
+
+static void read_config(void)
+{
+	if (cronscan(GCRONDIR, &jobs)) {
+		fputs("Error reading configuration. Continuing anyway.\n",
+		      stderr);
+	}
+}
+
+static void cleanup_config(void)
+{
+	crontab_t *t;
+
+	while (jobs != NULL) {
+		t = jobs;
+		jobs = jobs->next;
+		delcron(t);
+	}
+}
+
+static int timeout_minutes(int minutes)
+{
+	time_t now = time(NULL);
+	struct tm t;
+
+	localtime_r(&now, &t);
+	return minutes * 60 + 30 - t.tm_sec;
+}
+
+static int calc_timeout(void)
+{
+	time_t now = time(NULL), future;
+	struct tm tmstruct;
+	crontab_t mask, *t;
+	int minutes;
+
+	for (minutes = 0; minutes < 120; ++minutes) {
+		future = now + minutes * 60;
+
+		localtime_r(&future, &tmstruct);
+		cron_tm_to_mask(&mask, &tmstruct);
+
+		for (t = jobs; t != NULL; t = t->next) {
+			if (cron_should_run(t, &mask))
+				goto out;
+		}
+	}
+out:
+	return timeout_minutes(minutes ? minutes : 1);
+}
+
+static void runjobs(void)
+{
+	time_t now = time(NULL);
+	struct tm tmstruct;
+	crontab_t mask, *t;
+
+	localtime_r(&now, &tmstruct);
+	cron_tm_to_mask(&mask, &tmstruct);
+
+	for (t = jobs; t != NULL; t = t->next) {
+		if (cron_should_run(t, &mask))
+			runjob(t);
+	}
+}
+
+static void sighandler(int signo)
+{
+	pid_t pid;
+
+	switch (signo) {
+	case SIGINT:
+	case SIGTERM:
+		run = 0;
+		break;
+	case SIGHUP:
+		rescan = 1;
+		break;
+	case SIGCHLD:
+		while ((pid = waitpid(-1, NULL, WNOHANG)) != -1)
+			;
+		break;
+	}
+}
+
+int main(void)
+{
+	struct timespec stime;
+	struct sigaction act;
+	int timeout;
+
+	memset(&act, 0, sizeof(act));
+	act.sa_handler = sighandler;
+	sigaction(SIGINT, &act, NULL);
+	sigaction(SIGTERM, &act, NULL);
+	sigaction(SIGHUP, &act, NULL);
+	sigaction(SIGCHLD, &act, NULL);
+
+	while (run) {
+		if (rescan == 1) {
+			cleanup_config();
+			read_config();
+			timeout = timeout_minutes(1);
+			rescan = 0;
+		} else {
+			runjobs();
+			timeout = calc_timeout();
+		}
+
+		stime.tv_sec = timeout;
+		stime.tv_nsec = 0;
+
+		while (nanosleep(&stime, &stime) != 0 && run && !rescan) {
+			if (errno != EINTR) {
+				perror("nanosleep");
+				break;
+			}
+		}
+	}
+
+	return EXIT_SUCCESS;
+}