log.h File Reference

System logging header. More...

Detailed Description

System logging header.

This header offers a bunch of "LOG_*" functions that, with the default implementation, just use printf, but honour a verbosity level.

If desired, it is possible to implement a log module which then will be used instead the default printf-based implementation. In order to do so, the log module has to

1. provide "log_module.h"
2. have a name starting with "log_" or depend on the pseudo-module LOG,
3. implement log_write()

See "sys/log/log_printfnoformat" for an example.

Author

Kaspar Schleiser kaspa.nosp@m.r@sc.nosp@m.hleis.nosp@m.er.d.nosp@m.e

Definition in file log.h.

#include <stdio.h>

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Macros
#define	log_write(level, ...)   printf(__VA_ARGS__)
	Default log_write function, just maps to printf.
#define	LOG_LEVEL   LOG_INFO
	Default log level define.
#define	LOG(level, ...)
	Log message if level <= LOG_LEVEL. More...
enum	{   LOG_NONE, LOG_ERROR, LOG_WARNING, LOG_INFO,   LOG_DEBUG, LOG_ALL }
	defined log levels More...

Logging convenience defines
#define	LOG_ERROR(...)   LOG(LOG_ERROR, __VA_ARGS__)
#define	LOG_WARNING(...)   LOG(LOG_WARNING, __VA_ARGS__)
#define	LOG_INFO(...)   LOG(LOG_INFO, __VA_ARGS__)
#define	LOG_DEBUG(...)   LOG(LOG_DEBUG, __VA_ARGS__)

Macro Definition Documentation

LOG

#define LOG	(		level,
			...
	)

Value:

        do { \
        if ((level) <= LOG_LEVEL) log_write((level), __VA_ARGS__); } while (0U)

Log message if level <= LOG_LEVEL.

Definition at line 83 of file log.h.

Enumeration Type Documentation

anonymous enum

anonymous enum

defined log levels

These are the logging levels a user can choose. The idea is to set LOG_LEVEL to one of these values in the application's Makefile. That will restrict output of log statements to those with equal or lower log level.

The default log level is LOG_INFO, which will print every message.

The log function calls of filtered messages will be optimized out at compile time, so a lower log level might result in smaller code size.

Enumerator
LOG_NONE	Lowest log level, will output nothing.
LOG_ERROR	Error log level, will print only critical, non-recoverable errors like hardware initialization failures.
LOG_WARNING	Warning log level, will print warning messages for temporary errors.
LOG_INFO	Informational log level, will print purely informational messages like successful system bootup, network link state, ...
LOG_DEBUG	Debug log level, printing developer stuff considered too verbose for production use.
LOG_ALL	print everything

Definition at line 51 of file log.h.