Add syslog logging

1 files changed, 57 insertions, 24 deletions

diff --git a/src/modbuslog.c b/src/modbuslog.c
index ece8aca..fd1f00d 100644
--- a/src/modbuslog.c
+++ b/src/modbuslog.c
@@ -38,7 +38,7 @@
 #include <net/if.h>
 #include <string.h>
 
-
+#include <syslog.h>
 
 // handle SIGALRM by resetting it
 void minute_check(int signum) {
@@ -46,7 +46,8 @@ void minute_check(int signum) {
 }
 
 // get mac address of primary interface eth0
-char *mac_address() {
+char *
+mac_address() {
 	int s;
 	struct ifreq ifr;
 
@@ -70,18 +71,22 @@ char *mac_address() {
 
 int main(int argc, char *argv[]) {
 
-	const char *configfile = "/etc/modbuslog.cfg";
-
 	int DEBUG = 0;
+	int SYSLOG_CONSOLE_OUTPUT = 0;
 	int k;
 
 	// check the argv array for strings matching -d
 	for (k = 1; k < argc; k++) {
 		if (strcmp(argv[k], "-d") == 0) {
 			DEBUG = 1;
+			SYSLOG_CONSOLE_OUTPUT = LOG_PERROR;
 		}
 	}
 
+	openlog("modbuslog", SYSLOG_CONSOLE_OUTPUT | LOG_PID | LOG_CONS, LOG_USER);
+	syslog(LOG_INFO, "modbuslog starting");
+
+	const char *configfile = "/etc/modbuslog.cfg";
 	config_t cfg;
 	//config_setting_t *setting;
 
@@ -100,8 +105,10 @@ int main(int argc, char *argv[]) {
 		fprintf(stderr, "%s:%d - %s\n", config_error_file(&cfg),
 				config_error_line(&cfg), config_error_text(&cfg));
 		config_destroy(&cfg);
-		fprintf(stderr, "Unable to find configfile.\n");
+		syslog(LOG_ERR, "Unable to find configfile");
 		return -1;
+	} else {
+		syslog(LOG_INFO, "configfile found successfully");
 	}
 
 	// die if core config file options aren't there
@@ -111,16 +118,15 @@ int main(int argc, char *argv[]) {
 			&& config_lookup_string(&cfg, "modbus.parity", &modbus_parity)
 			&& config_lookup_int(&cfg, "modbus.stop_bits", &modbus_stop_bits)
 			&& config_lookup_int(&cfg, "modbus.retry", &modbus_retry))) {
-		fprintf(stderr,
-				"Incomplete modbus configuration. Check configuration file.\n");
+		syslog(LOG_ERR,
+				"Incomplete modbus configuration. Check configuration file");
+		closelog();
 		return -1;
 	}
 
-	if (DEBUG) {
-		printf("%s %s %d %c %d %d\n", mac_address(), modbus_device_address,
-				modbus_baud_rate, modbus_parity[0], modbus_data_bits,
-				modbus_stop_bits);
-	}
+	syslog(LOG_INFO, "%s %s %d %c %d %d", mac_address(), modbus_device_address,
+			modbus_baud_rate, modbus_parity[0], modbus_data_bits,
+			modbus_stop_bits);
 
 	modbus_t *ctx;
 	uint16_t tab_reg[4];
@@ -191,7 +197,7 @@ int main(int argc, char *argv[]) {
 			// if we match the required time for the reading
 			if (unixtime_min % intervalduration == 0) {
 				//printf("specified minute.  %d %d\n", unixtime_min,
-				//		intervalduration);
+				//              intervalduration);
 
 				// attempt to create new modbus connection
 				ctx = modbus_new_rtu(modbus_device_address, modbus_baud_rate,
@@ -200,16 +206,15 @@ int main(int argc, char *argv[]) {
 				modbus_set_slave(ctx, slaveid);
 				modbus_set_debug(ctx, DEBUG);
 
-				if (ctx == NULL) {
-					fprintf(stderr, "Unable to create libmodbus object.\n");
-					//return -1;
+				if (ctx == NULL)
+				{
+					syslog(LOG_ERR, "Unable to create libmodbus object");
 				}
 
 				if (modbus_connect(ctx) == -1) {
-					fprintf(stderr, "Connection failed: %s\n",
+					syslog(LOG_ERR, "libmodbus: Connection failed: %s",
 							modbus_strerror(errno));
 					modbus_free(ctx);
-					//return -1;
 				}
 
 				int retry = 0;
@@ -234,10 +239,11 @@ int main(int argc, char *argv[]) {
 						break;
 					}
 					if (rc == -1) {
-						fprintf(stderr, "ERROR: %s\n", modbus_strerror(errno));
+						syslog(LOG_ERR, "libmodbus error: %s",
+								modbus_strerror(errno));
 					}
 					retry++;
-				} while ((rc != -1) && (retry < (modbus_retry+1)));
+				} while ((rc != -1) && (retry < (modbus_retry + 1)));
 
 				//MODBUS_GET_HIGH_BYTE(data);
 				//MODBUS_GET_LOW_BYTE(data);
@@ -264,6 +270,8 @@ int main(int argc, char *argv[]) {
 					fclose(fp);
 				} else {
 					// file doesn't exist. create it.
+					syslog(LOG_NOTICE, "logfile does not exist");
+					syslog(LOG_INFO, "creating file: %s", filename);
 					FILE *fp = fopen(filename, "w");
 					fprintf(
 							fp,
@@ -273,6 +281,8 @@ int main(int argc, char *argv[]) {
 
 				FILE *filehandle = fopen(filename, "a+");
 
+				syslog(LOG_DEBUG, "opening file for append: %s", filename);
+
 				int16_t registervalue = 0;
 
 				int p;
@@ -304,12 +314,26 @@ int main(int argc, char *argv[]) {
 				struct tm lc = *localtime(&unixtime_min);
 
 				int intervalid;
-				FILE *intervalfile = fopen("/var/modbuslog/interval/interval.txt", "r+");
+				FILE *intervalfile = fopen(
+						"/var/modbuslog/interval/interval.txt", "r+");
+
+				if (intervalfile) {
+					fclose(intervalfile);
+				} else {
+					// file doesn't exist. create it.
+					syslog(LOG_NOTICE, "interval file does not exist");
+					syslog(LOG_INFO, "attempting to create file: %s",
+							intervalfile);
+					FILE *intervalfile = fopen(filename, "w");
+					fprintf(intervalfile, "0\n");
+					fclose(intervalfile);
+				}
+
 				fscanf(intervalfile, "%d", &intervalid);
 				//handle 32bit signed overflow
-				if(intervalid==2147483647){
-					intervalid=0;
-				}else{
+				if (intervalid == 2147483647) {
+					intervalid = 0;
+				} else {
 					intervalid++;
 				}
 				rewind(intervalfile);
@@ -326,6 +350,15 @@ int main(int argc, char *argv[]) {
 						registervalue);
 				fclose(filehandle);
 
+				syslog(
+						LOG_DEBUG,
+						"%i|%04i%02i%02i|%02i%02i%02i|%04i%02i%02i|%02i%02i%02i|%i|%i|%i\n",
+						intervalid, utc.tm_year + 1900, utc.tm_mon + 1,
+						utc.tm_mday, utc.tm_hour, utc.tm_min, utc.tm_sec,
+						lc.tm_year + 1900, lc.tm_mon + 1, lc.tm_mday,
+						lc.tm_hour, lc.tm_min, lc.tm_sec, slaveid, startaddress,
+						registervalue);
+
 				modbus_close(ctx);
 				modbus_free(ctx);