logger library and flag to run as daemon

1 files changed, 78 insertions, 0 deletions

diff --git a/lib/logger/logger.c b/lib/logger/logger.c
new file mode 100644
index 0000000..64a6754
--- /dev/null
+++ b/lib/logger/logger.c
@@ -0,0 +1,78 @@
+#include <syslog.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include "logger.h"
+
+static int use_syslog = 0;
+
+void
+logger_init(const char *name, int daemon_flag)
+{
+	use_syslog = daemon_flag;
+	if (use_syslog)
+		openlog(name, LOG_PID, LOG_DAEMON);
+}
+
+void
+logger_close(void)
+{
+	if (use_syslog)
+		closelog();
+}
+
+void
+logger_log(enum logger_lvl level, const char *format, ...)
+{
+	int saved_errno = errno;
+	va_list vargs;
+	va_start(vargs, format);
+	if (use_syslog) {
+		switch (level) {
+		case log_lvl_info:
+			vsyslog(LOG_INFO, format, vargs);
+			break;
+		case log_lvl_warning:
+			vsyslog(LOG_WARNING, format, vargs);
+			break;
+		case log_lvl_err:
+			vsyslog(LOG_ERR, format, vargs);
+			break;
+		}
+	} else {
+		FILE *f = NULL;
+		switch (level) {
+		case log_lvl_info:
+			f = stdout;
+			fprintf(f, "[INFO] ");
+			break;
+		case log_lvl_warning:
+			f = stderr;
+			fprintf(f, "[WARNING] ");
+			break;
+		case log_lvl_err:
+			f = stderr;
+			fprintf(f, "[ERROR] ");
+			break;
+		default:
+			f = stderr;
+			fprintf(f, "[UNKNOWN] ");
+			break;
+		}
+		vfprintf(f, format, vargs);
+	}
+	errno = saved_errno;
+}
+
+void
+logger_perror(const char *s)
+{
+	int saved_errno = errno;
+	if (use_syslog) {
+		syslog(LOG_ERR, "%s: %s\n", s, strerror(errno));
+	} else {
+		perror(s);
+	}
+	errno = saved_errno;
+}