add missing logger

.gitignore

@@ -9,4 +9,4 @@ pro/*.c
 
 /.ccls-cache
 
-log.*
+/log.*

inc/log.h

@@ -0,0 +1,24 @@
+#ifndef LOG_H
+#define LOG_H
+
+#include <stdbool.h>
+
+#include "enum.h"
+
+void log_debug(const char *__restrict __format, ...);
+
+void log_info(const char *__restrict __format, ...);
+
+void log_warn(const char *__restrict __format, ...);
+
+void log_error(const char *__restrict __format, ...);
+
+void log_error_errno(const char *__restrict __format, ...);
+
+enum LogThreshold log_get_threshold(void);
+
+// false if not valid
+bool log_set_threshold(const char *s);
+
+#endif // LOG_H
+

src/log.c

@@ -0,0 +1,116 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include "enum.h"
+
+#include "log.h"
+
+char THRESHOLD_CHAR[] = {
+	'?',
+	'D',
+	'I',
+	'W',
+	'E',
+};
+
+char *THRESHOLD_LABEL[] = {
+	"",
+	"",
+	"",
+	"WARNING: ",
+	"ERROR: ",
+};
+
+enum LogThreshold log_threshold = LOG_THRESHOLD_DEFAULT;
+
+bool log_prefix = true;
+
+void print_prefix(const enum LogThreshold threshold, FILE *__restrict __stream) {
+	static char buf[16];
+	static time_t t;
+
+	t = time(NULL);
+
+	strftime(buf, sizeof(buf), "%H:%M:%S", localtime(&t));
+
+	fprintf(__stream, "%c [%s] ", THRESHOLD_CHAR[threshold], buf);
+}
+
+void log_(const enum LogThreshold threshold, const int eno, const char *__restrict __format, va_list __args) {
+	if (threshold < log_threshold) {
+		return;
+	}
+
+	static FILE *stream;
+
+	stream = threshold == ERROR ? stderr : stdout;
+
+	if (log_prefix) {
+		print_prefix(threshold, stream);
+	}
+
+	fprintf(stream, "%s", THRESHOLD_LABEL[threshold]);
+
+	vfprintf(stream, __format, __args);
+
+	if (eno) {
+		fprintf(stream, " %d: %s", eno, strerror(eno));
+	}
+
+	fprintf(stream, "\n");
+
+	fflush(stream);
+}
+
+void log_debug(const char *__restrict __format, ...) {
+	va_list args;
+	va_start(args, __format);
+	log_(DEBUG, 0, __format, args);
+	va_end(args);
+}
+
+void log_info(const char *__restrict __format, ...) {
+	va_list args;
+	va_start(args, __format);
+	log_(INFO, 0, __format, args);
+	va_end(args);
+}
+
+void log_warn(const char *__restrict __format, ...) {
+	va_list args;
+	va_start(args, __format);
+	log_(WARNING, 0, __format, args);
+	va_end(args);
+}
+
+void log_error(const char *__restrict __format, ...) {
+	va_list args;
+	va_start(args, __format);
+	log_(ERROR, 0, __format, args);
+	va_end(args);
+}
+
+void log_error_errno(const char *__restrict __format, ...) {
+	va_list args;
+	va_start(args, __format);
+	log_(ERROR, errno, __format, args);
+	va_end(args);
+}
+
+enum LogThreshold log_get_threshold(void) {
+	return log_threshold;
+}
+
+bool log_set_threshold(const char *s) {
+	enum LogThreshold t = log_threshold_val(s);
+	if (t) {
+		log_threshold = t;
+		return true;
+	}
+	return false;
+}
+