Add helper library for cron configuration

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>

1 files changed, 50 insertions, 0 deletions

diff --git a/lib/cron/crontab.c b/lib/cron/crontab.c
new file mode 100644
index 0000000..f761ec0
--- /dev/null
+++ b/lib/cron/crontab.c
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * Copyright (C) 2018 - David Oberhollenzer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <string.h>
+
+#include "crontab.h"
+
+void cron_tm_to_mask(crontab_t *out, struct tm *t)
+{
+	memset(out, 0, sizeof(*out));
+	out->minute     = 1UL << ((unsigned long)t->tm_min);
+	out->hour       = 1 << t->tm_hour;
+	out->dayofmonth = 1 << (t->tm_mday - 1);
+	out->month      = 1 << t->tm_mon;
+	out->dayofweek  = 1 << t->tm_wday;
+}
+
+bool cron_should_run(const crontab_t *t, const crontab_t *mask)
+{
+	if ((t->minute & mask->minute) == 0)
+		return false;
+
+	if ((t->hour & mask->hour) == 0)
+		return false;
+
+	if ((t->dayofmonth & mask->dayofmonth) == 0)
+		return false;
+
+	if ((t->month & mask->month) == 0)
+		return false;
+
+	if ((t->dayofweek & mask->dayofweek) == 0)
+		return false;
+
+	return true;
+}