scron

commit 94582629a78e4b213882ab407dfd119a16342c09
parent 981a9bc6275358bb6086d72268d4939062377c45
Author: Ari Malinen <ari.malinen@gmail.com>
Date:   Mon, 30 Jun 2014 02:26:39 +0300

better crontab parsing

Diffstat:
M
README
 | 
14
++++++++------
M
crond.c
 | 
78
++++++++++++++++++++++++++++++++++++++----------------------------------------

2 files changed, 46 insertions(+), 46 deletions(-)
diff --git a/README b/README
@@ -3,10 +3,12 @@ scron - simple cron daemon
 
 features
 --------
-Schedule tasks.
-Single daemon, config and initscript.
-Log to stdout and syslog.
-No mail support.
+schedule tasks
+single daemon, config and initscript
+log job output: command &>> /var/log/cron.log
+run as different user: su -c 'command' user
+log to stdout and syslog
+no mail support
 
 usage
 -----
@@ -18,5 +20,5 @@ usage: crond [options]
 example config
 --------------
 # tm_min, tm_hour, tm_mday, tm_mon, tm_wday, command
-0	5	*	*	*	updatedb	# 06:00 every day
-29	4	*	*	1-5	emerge --sync	# 5:30 every weekday
+0	6	*	*	*	updatedb	# 06:00 every day
+30	5	*	*	1-5	emerge --sync	# 5:30 every weekday
diff --git a/crond.c b/crond.c
@@ -1,16 +1,14 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
-#include <ctype.h>
 #include <time.h>
 #include <unistd.h>
 #include <sys/wait.h>
 #include <sys/types.h>
+#include <linux/limits.h>
 #include <syslog.h>
 
-#define LEN 256
-
-char config[LEN+1] = "/etc/crontab";
+char config[PATH_MAX] = "/etc/crontab";
 
 void arg(int argc, char *argv[]) {
 	int i;
@@ -21,7 +19,7 @@ void arg(int argc, char *argv[]) {
 			pid = fork();
 			if (pid < 0) {
 				fprintf(stderr, "error: failed to fork daemon\n");
-				syslog(LOG_NOTICE, "error: failed to fork daemon");
+				syslog(LOG_WARNING, "error: failed to fork daemon");
 			} else if (pid == 0) {
 				setsid();
 				fclose(stdin);
@@ -33,10 +31,10 @@ void arg(int argc, char *argv[]) {
 		} else if (!strcmp("-f", argv[i])) {
 			if (argv[i+1] == NULL || argv[i+1][0] == '-') {
 				fprintf(stderr, "error: -f needs parameter\n");
-				syslog(LOG_NOTICE, "error: -f needs parameter");
+				syslog(LOG_WARNING, "error: -f needs parameter");
 				exit(EXIT_FAILURE);
 			}
-			strncpy(config, argv[++i], LEN);
+			strncpy(config, argv[++i], PATH_MAX-1);
 		} else {
 			fprintf(stderr, "usage: %s [options]\n", argv[0]);
 			fprintf(stderr, "-h        help\n");
@@ -58,34 +56,34 @@ int parsecolumn(char *col, int y, int x) {
 
 	if (x >= 0 && x <= 4) {
 		endptr = "";
+		endptr2 = "";
 		entry = strtol(col, &endptr, 0);
-		if (!strcmp("*", col)) {
-			return 0;
-		} else if (*endptr == '-') {
+		entry2 = -1;
+		if (*endptr == '-') {
 			endptr++;
-			endptr2 = "";
 			entry2 = strtol(endptr, &endptr2, 0);
-			if (*endptr2 != '\0' || entry2 < 0 || entry2 > 59) {
-				fprintf(stderr, "error: %s line %d column %d\n", config, y+1, x+1);
-				syslog(LOG_NOTICE, "error: %s line %d column %d", config, y+1, x+1);
-				return 1;
-			} else if ((x == 0 && entry <= tm->tm_min && entry2 >= tm->tm_min) ||
+			endptr = "";
+		}
+
+		if (!strcmp("*", col)) {
+			return 0;
+		} else if (*endptr != '\0' || *endptr2 != '\0') {
+			fprintf(stderr, "error: %s line %d column %d\n", config, y+1, x+1);
+			syslog(LOG_WARNING, "error: %s line %d column %d", config, y+1, x+1);
+		} else if (entry2 == -1) {
+			if ((x == 0 && entry == tm->tm_min) ||
+					(x == 1 && entry == tm->tm_hour) ||
+					(x == 2 && entry == tm->tm_mday) ||
+					(x == 3 && entry == tm->tm_mon) ||
+					(x == 4 && entry == tm->tm_wday))
+				return 0;
+		} else {
+			if ((x == 0 && entry <= tm->tm_min && entry2 >= tm->tm_min) ||
 					(x == 1 && entry <= tm->tm_hour && entry2 >= tm->tm_hour) ||
 					(x == 2 && entry <= tm->tm_mday && entry2 >= tm->tm_mday) ||
 					(x == 3 && entry <= tm->tm_mon && entry2 >= tm->tm_mon) ||
-					(x == 4 && entry <= tm->tm_wday && entry2 >= tm->tm_wday)) {
+					(x == 4 && entry <= tm->tm_wday && entry2 >= tm->tm_wday))
 				return 0;
-			}
-		} else if (*endptr != '\0' || entry < 0 || entry > 59) {
-			fprintf(stderr, "error: %s line %d column %d\n", config, y+1, x+1);
-			syslog(LOG_NOTICE, "error: %s line %d column %d", config, y+1, x+1);
-			return 1;
-		} else if ((x == 0 && entry == tm->tm_min) ||
-				(x == 1 && entry == tm->tm_hour) ||
-				(x == 2 && entry == tm->tm_mday) ||
-				(x == 3 && entry == tm->tm_mon) ||
-				(x == 4 && entry == tm->tm_wday)) {
-			return 0;
 		}
 	}
 
@@ -101,13 +99,13 @@ void runjob(char *cmd) {
 	pid = fork();
 	if (pid < 0) {
 		fprintf(stderr, "error: failed to fork job: %s time: %s", cmd, ctime(&t));
-		syslog(LOG_NOTICE, "error: failed to fork job: %s", cmd);
+		syslog(LOG_WARNING, "error: failed to fork job: %s", cmd);
 	} else if (pid == 0) {
 		printf("run: %s pid: %d time: %s", cmd, (int) getpid(), ctime(&t));
-		syslog(LOG_NOTICE, "run: %s pid: %d", cmd, (int) getpid());
+		syslog(LOG_INFO, "run: %s pid: %d", cmd, (int) getpid());
 		execl("/bin/sh", "/bin/sh", "-c", cmd, (char *) NULL);
 		fprintf(stderr, "error: job failed: %s time: %s\n", cmd, ctime(&t));
-		syslog(LOG_NOTICE, "error: job failed: %s", cmd);
+		syslog(LOG_WARNING, "error: job failed: %s", cmd);
 		exit(EXIT_FAILURE);
 	}
 }
@@ -121,18 +119,18 @@ void checkreturn(void) {
 
 	while ((pid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
 		printf("complete: pid %d, return: %d time: %s", (int) pid, status, ctime(&t));
-		syslog(LOG_NOTICE, "complete: pid: %d return: %d", (int) pid, status);
+		syslog(LOG_INFO, "complete: pid: %d return: %d", (int) pid, status);
 	}
 }
 
 int main(int argc, char *argv[]) {
 	int y, x;
-	char line[LEN+1];
+	char line[PATH_MAX];
 	char *col;
 	time_t t;
 	FILE *fp;
 
-	openlog(argv[0], LOG_CONS | LOG_PID, LOG_LOCAL1);
+	openlog(argv[0], LOG_CONS | LOG_PID, LOG_DAEMON);
 
 	arg(argc, argv);
 
@@ -142,12 +140,12 @@ int main(int argc, char *argv[]) {
 
 		if ((fp = fopen(config, "r")) == NULL) {
 			fprintf(stderr, "error: cant read %s\n", config);
-			syslog(LOG_NOTICE, "error: cant read %s", config);
+			syslog(LOG_WARNING, "error: cant read %s", config);
 			continue;
 		}
 
-		for (y = 0; fgets(line, LEN+1, fp); y++) {
-			if (line[0] == '#' || line[0] == '\n')
+		for (y = 0; fgets(line, PATH_MAX-1, fp); y++) {
+			if (line[0] == '#' || line[0] == '\n' || line[0] == '\0')
 				continue;
 
 			strtok(line, "\n");
@@ -157,8 +155,8 @@ int main(int argc, char *argv[]) {
 					continue;
 				else if (x == 5)
 					runjob(col);
-
-				break;
+				else
+					break;
 			}
 		}
 
@@ -167,5 +165,5 @@ int main(int argc, char *argv[]) {
 	}
 
 	closelog();
-	return 0;
+	return EXIT_SUCCESS;
 }