added my fancy C logging library v0.000001

c/color.h

@@ -0,0 +1,33 @@
+/** Various helper functions.
+ *
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2014, Institute for Automation of Complex Power Systems, EONERC
+ * @file
+ */
+
+#ifndef _COLOR_H_
+#define _COLOR_H_
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <string.h>
+
+/* Some color escape codes for pretty log messages */
+#define GRY(str)	"\e[30m" str "\e[0m" /**< Print str in gray */
+#define RED(str)	"\e[31m" str "\e[0m" /**< Print str in red */
+#define GRN(str)	"\e[32m" str "\e[0m" /**< Print str in green */
+#define YEL(str)	"\e[33m" str "\e[0m" /**< Print str in yellow */
+#define BLU(str)	"\e[34m" str "\e[0m" /**< Print str in blue */
+#define MAG(str)	"\e[35m" str "\e[0m" /**< Print str in magenta */
+#define CYN(str)	"\e[36m" str "\e[0m" /**< Print str in cyan */
+#define WHT(str)	"\e[37m" str "\e[0m" /**< Print str in white */
+#define BLD(str)	"\e[1m"  str "\e[0m" /**< Print str in bold */
+
+#define GFX(chr)	"\e(0" chr "\e(B"
+#define UP(n)		"\e[" ## n ## "A"
+#define DOWN(n)	 	"\e[" ## n ## "B"
+#define RIGHT(n)	"\e[" ## n ## "C"
+#define LEFT(n)	 	"\e[" ## n ## "D"
+
+#endif /* _COLOR_H_ */

c/logger.c

@@ -0,0 +1,70 @@
+#include <stdio.h>
+
+#include "color.h"
+#include "logger.h"
+
+/* This global variable contains the debug level for debug() and assert() macros */
+int _debug = V;
+int _indent = 0;
+
+static struct timeval epoch;
+
+void _outdent(int *old)
+{
+	_indent = *old;
+}
+
+void log_reset()
+{
+	gettimeofday(&epoch, NULL);
+}
+
+void log_level(int lvl)
+{
+	_debug = lvl;
+}
+
+void print(enum log_level lvl, const char *fmt, ...)
+{
+	struct timeval tv;
+
+	va_list ap;
+	va_start(ap, fmt);
+
+	/* Timestamp */
+	gettimeofday(&tv, NULL);
+	
+	fprintf(stderr, "%8.3f ", timespec_delta(&epoch, &tv));
+
+	switch (lvl) {
+		case DEBUG: fprintf(stderr, BLD("%-5s "), GRY("Debug")); break;
+		case INFO:  fprintf(stderr, BLD("%-5s "), WHT(" Info")); break;
+		case WARN:  fprintf(stderr, BLD("%-5s "), YEL(" Warn")); break;
+		case ERROR: fprintf(stderr, BLD("%-5s "), RED("Error")); break;
+	}
+
+	if (_indent) {
+		for (int i = 0; i < _indent-1; i++)
+			fprintf(stderr, GFX("\x78") " ");
+
+		fprintf(stderr, GFX("\x74") " ");
+	}
+
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "\n");
+
+	va_end(ap);
+}
+
+double timespec_delta(struct timeval *start, struct timeval *end)
+{
+	double sec  = end->tv_sec - start->tv_sec;
+	double usec = end->tv_usec - start->tv_usec;
+
+	if (usec < 0) {
+		sec  -= 1;
+		usec += 1e6;
+	}
+
+	return sec + usec * 1e-6;
+}

c/logger.h

@@ -0,0 +1,85 @@
+#include <stdlib.h>
+#include <sys/time.h>
+
+#ifndef V
+ #define V 5
+#endif
+
+#ifdef __GNUC__
+ #define EXPECT(x, v)	__builtin_expect(x, v)
+ #define INDENT		int __attribute__ ((__cleanup__(_outdent), unused)) _old_indent = _indent++; 
+#else
+ #define EXPECT(x, v)	(x)
+ #define INDENT		;
+#endif
+
+/* These global variables allow changing the output style and verbosity */
+extern int _debug;
+extern int _indent;
+
+void outdent(int *old);
+
+/** The log level which is passed as first argument to print() */
+enum log_level { DEBUG, INFO, WARN, ERROR };
+
+/** Reset the timer for log outputs to zero. */
+void log_reset();
+
+/** Set the current logging level */
+void log_level(int lvl);
+
+/** Get delta between two timespec structs */
+double timespec_delta(struct timeval *start, struct timeval *end);
+
+/** Logs variadic messages to stdout.
+ *
+ * @param lvl The log level
+ * @param fmt The format string (printf alike)
+ */
+void print(enum log_level lvl, const char *fmt, ...);
+
+/** Check assertion and exit if failed. */
+#define assert(exp) do { \
+	if (EXPECT(!exp, 0)) { \
+		print(ERROR, "Assertion failed: '%s' in %s, %s:%d", \
+			#exp, __FUNCTION__, __BASE_FILE__, __LINE__); \
+		exit(EXIT_FAILURE); \
+	} } while (0)
+
+/** Printf alike debug message with level. */
+#define debug(lvl, msg, ...) do { \
+	if (lvl <= _debug) \
+		print(DEBUG, msg, ##__VA_ARGS__); \
+	} while (0)
+
+/** Printf alike info message. */
+#define info(msg, ...) do { \
+		print(INFO, msg, ##__VA_ARGS__); \
+	} while (0)
+
+/** Printf alike warning message. */
+#define warn(msg, ...) do { \
+		print(WARN, msg, ##__VA_ARGS__); \
+	} while (0)
+
+/** Print error and exit. */
+#define error(msg, ...) do { \
+		print(ERROR, msg, ##__VA_ARGS__); \
+		exit(EXIT_FAILURE); \
+	} while (0)
+
+/** Print error and strerror(errno). */
+#define serror(msg, ...) do { \
+		print(ERROR, msg ": %s", ##__VA_ARGS__, \
+			strerror(errno)); \
+		exit(EXIT_FAILURE); \
+	} while (0)
+
+/** Print configuration error and exit. */
+#define cerror(c, msg, ...) do { \
+		print(ERROR, msg " in %s:%u", ##__VA_ARGS__, \
+			(config_setting_source_file(c)) ? \
+			 config_setting_source_file(c) : "(stdio)", \
+			config_setting_source_line(c)); \
+		exit(EXIT_FAILURE); \
+	} while (0)

c/logger_test.c

@@ -0,0 +1,48 @@
+#include <unistd.h>
+
+#include "logger.h"
+
+void recursive(int i)
+{ INDENT
+	info("We are inside the recursive function. Current level = %d", i);
+
+	if (i) {
+		usleep(rand() * 3e6 / RAND_MAX);
+		recursive(i-1);
+	}
+}
+
+void goodbye()
+{
+	warn("There was an error message. Program terminating...");
+}
+
+int main(int argc, char *argv[])
+{
+	/* Reset log timer to zero */
+	epoch_reset();
+	
+	/* Register exit() handler */
+	atexit(goodbye);
+	
+	info("Welcome, this is a little program to demo the logger");
+
+	recursive(5);
+
+	/* Some other types of messages */
+	info("This is a info message");
+	warn("This is a warning message");
+	
+	/* Debug messages are only printed if the level (1st arg) is higher than the current level */
+	debug(3, "This is a debug message");
+	
+	/* INDENT's are valid per code block */
+	{ INDENT
+		info("This is an indented message");
+	}
+
+	/* Error messages will cause program termination */
+	error("This is an error message");
+	
+	return 0;
+}