add log.c/log.h which contain all the log related macros and functions

include/log.h

@@ -0,0 +1,65 @@
+/*
+ * vim:ts=8:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ */
+#ifndef _LOG_H
+#define _LOG_H
+
+#include <stdarg.h>
+
+/** ##__VA_ARGS__ means: leave out __VA_ARGS__ completely if it is empty, that
+   is, delete the preceding comma */
+#define LOG(fmt, ...) verboselog(fmt, ##__VA_ARGS__)
+#define ELOG(fmt, ...) errorlog("ERROR: " fmt, ##__VA_ARGS__)
+#define DLOG(fmt, ...) debuglog(LOGLEVEL, "%s:%s:%d - " fmt, __FILE__, __FUNCTION__, __LINE__, ##__VA_ARGS__)
+
+extern char *loglevels[];
+
+/**
+ * Enables the given loglevel.
+ *
+ */
+void add_loglevel(const char *level);
+
+/**
+ * Set verbosity of i3. If verbose is set to true, informative messages will
+ * be printed to stdout. If verbose is set to false, only errors will be
+ * printed.
+ *
+ */
+void set_verbosity(bool _verbose);
+
+/**
+ * Logs the given message to stdout while prefixing the current time to it,
+ * but only if the corresponding debug loglevel was activated.
+ *
+ */
+void debuglog(int lev, char *fmt, ...);
+
+/**
+ * Logs the given message to stdout while prefixing the current time to it.
+ *
+ */
+void errorlog(char *fmt, ...);
+
+/**
+ * Logs the given message to stdout while prefixing the current time to it,
+ * but only if verbose mode is activated.
+ *
+ */
+void verboselog(char *fmt, ...);
+
+/**
+ * Logs the given message to stdout while prefixing the current time to it.
+ * This is to be called by LOG() which includes filename/linenumber
+ *
+ */
+void slog(char *fmt, va_list args);
+
+#endif

src/log.c

@@ -0,0 +1,121 @@
+/*
+ * vim:ts=8:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ * src/log.c: handles the setting of loglevels, contains the logging functions.
+ *
+ */
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include "util.h"
+#include "log.h"
+
+/* loglevels.h is autogenerated at make time */
+#include "loglevels.h"
+
+static uint32_t loglevel = 0;
+static bool verbose = false;
+
+/**
+ * Set verbosity of i3. If verbose is set to true, informative messages will
+ * be printed to stdout. If verbose is set to false, only errors will be
+ * printed.
+ *
+ */
+void set_verbosity(bool _verbose) {
+        verbose = _verbose;
+}
+
+/**
+ * Enables the given loglevel.
+ *
+ */
+void add_loglevel(const char *level) {
+	/* Handle the special loglevel "all" */
+	if (strcasecmp(level, "all") == 0) {
+		loglevel = UINT32_MAX;
+		return;
+	}
+
+	for (int i = 0; i < sizeof(loglevels) / sizeof(char*); i++) {
+		if (strcasecmp(loglevels[i], level) != 0)
+			continue;
+
+		/* The position in the array (plus one) is the amount of times
+		 * which we need to shift 1 to the left to get our bitmask for
+		 * the specific loglevel. */
+		loglevel |= (1 << (i+1));
+		break;
+	}
+}
+
+/*
+ * Logs the given message to stdout while prefixing the current time to it.
+ * This is to be called by *LOG() which includes filename/linenumber/function.
+ *
+ */
+void vlog(char *fmt, va_list args) {
+        char timebuf[64];
+
+        /* Get current time */
+        time_t t = time(NULL);
+        /* Convert time to local time (determined by the locale) */
+        struct tm *tmp = localtime(&t);
+        /* Generate time prefix */
+        strftime(timebuf, sizeof(timebuf), "%x %X - ", tmp);
+        printf("%s", timebuf);
+        vprintf(fmt, args);
+}
+
+/**
+ * Logs the given message to stdout while prefixing the current time to it,
+ * but only if verbose mode is activated.
+ *
+ */
+void verboselog(char *fmt, ...) {
+        va_list args;
+
+	if (!verbose)
+		return;
+
+        va_start(args, fmt);
+        vlog(fmt, args);
+        va_end(args);
+}
+
+/**
+ * Logs the given message to stdout while prefixing the current time to it.
+ *
+ */
+void errorlog(char *fmt, ...) {
+        va_list args;
+
+        va_start(args, fmt);
+        vlog(fmt, args);
+        va_end(args);
+}
+
+/*
+ * Logs the given message to stdout while prefixing the current time to it,
+ * but only if the corresponding debug loglevel was activated.
+ * This is to be called by DLOG() which includes filename/linenumber
+ *
+ */
+void debuglog(int lev, char *fmt, ...) {
+	va_list args;
+
+	if ((loglevel & lev) == 0)
+		return;
+
+        va_start(args, fmt);
+        vlog(fmt, args);
+        va_end(args);
+}