Logging

Logging utilities. More...

Macros
#define	CSNIP_LOG_PRIO_DEBUGV   0
	Verbose debugging priority. More...
#define	CSNIP_LOG_PRIO_DEBUG   10
	Debugging priority. More...
#define	CSNIP_LOG_PRIO_INFO   20
	Informational priority.
#define	CSNIP_LOG_PRIO_NOTICE   30
	Notice.
#define	CSNIP_LOG_PRIO_WARN   40
	Warnings.
#define	CSNIP_LOG_PRIO_ERR   50
	Errors.
#define	CSNIP_LOG_PRIO_MIN   0
	Minimum compiled-in prioriy. More...
#define	csnip_log_Mesg(prio, ...)    csnip_log_MesgForComp(CSNIP_LOG_COMPONENT, prio, __VA_ARGS__)
	Log a message. More...
#define	csnip_log_MesgForComp(comp, prio, ...)
	Log a message for a specified component. More...
#define	csnip_log_Perror(prio, ...)    csnip_log_PerrorForComp(CSNIP_LOG_COMPONENT, prio, __VA_ARGS__)
	Log an errno error. More...
#define	csnip_log_PerrorForComp(comp, prio, ...)
	Log an errno error for a specified component. More...

Functions
void	csnip_log_config0 (const char *filters_expr, FILE *log_out)
	Simple logger configuration. More...

Detailed Description

This library provides a simple interface for logging. Each log message is associated a priority as well as with context including the source file name and line number, but in particular a component name. The component name is the expansion of the macro CSNIP_LOG_COMPONENT where csnip_log_Mesg() is expanded.

Log output can be filtered based on priority and regular expressions matching the component name, see csnip_log_config0() for details.

Macro Definition Documentation

csnip_log_Mesg

#define csnip_log_Mesg	(		prio,
			...
	)		csnip_log_MesgForComp(CSNIP_LOG_COMPONENT, prio, __VA_ARGS__)

Logs a message; this requires the CSNIP_LOG_COMPONENT macro to be defined. The CSNIP_LOG_PRIO_MIN macro can be used to filter out lower priority messages at compile time for performance reasons.

See the documentation of csnip_log_config0() on what messages are printed by default and how the logger can be configured.

The CSNIP_LOG_COMPONENT must be a string with static lifetime, ideally a string literal.

Parameters

prio	logging priority.
...	printf-style format and arguments.

csnip_log_MesgForComp

#define csnip_log_MesgForComp	(		comp,
			prio,
			...
	)

Variant of csnip_log_Mesg() with the logging component specified as an argument. Does not require CSNIP_LOG_COMPONENT to be defined.

Parameters

comp	the component, must be a string literal.
prio	logging priority.
...	printf-style format and arguments.

csnip_log_Perror

#define csnip_log_Perror	(		prio,
			...
	)		csnip_log_PerrorForComp(CSNIP_LOG_COMPONENT, prio, __VA_ARGS__)

This is the logging module's variant of perror(3). It prints the log message as given here, and then, separated by a colon, the error message corresponding to the errno value.

Parameters

prio	loggin priority.
...	printf-style format and arguments.

csnip_log_PerrorForComp

#define csnip_log_PerrorForComp	(		comp,
			prio,
			...
	)

Variant of csnip_log_Perror() with the logging component specified as an argument. Does not require CSNIP_LOG_COMPONENT to be defined.

Parameters

comp	the component, must be a string literal.
prio	loggin priority.
...	printf-style format and arguments.

CSNIP_LOG_PRIO_DEBUG

#define CSNIP_LOG_PRIO_DEBUG   10

These debug levels are suitable for general messages useful when debugging.

CSNIP_LOG_PRIO_DEBUGV

#define CSNIP_LOG_PRIO_DEBUGV   0

DEBUGV can be very detailed; possibly too detailed to run entire programs or larger modules with this debug level.

CSNIP_LOG_PRIO_MIN

#define CSNIP_LOG_PRIO_MIN   0

This macro is only defined if not already predefined; the intent is the user can set it as desired.

Log messages with lower priorities will not be compiled in. Compiler optimizations, if enabled, will typically cause the string constants such as the components and file names, as well as the log message itself to be absent from binaries in those cases.

Function Documentation

csnip_log_config0()

void csnip_log_config0	(	const char *	filters_expr,
		FILE *	log_out
	)

By default all messages of priority CSNIP_LOG_PRIO_NOTICE or higher will be logged. This function provides a simple interface to configure the logger.

Parameters

filters_expr

Filter expressions string. The string is colon-separated string of expressions of the form RE~PRIO, where RE is a POSIX extended regular expression that is matched against the component string, and PRIO minimum priority value for a message to be printed. If a message satisfies any of the filter expression constraints, it will be printed. If RE is omitted, all messages are matched, if ~PRIO or PRIO is omitted, the priority is taken to be CSNIP_LOG_PRIO_NOTICE . If filter_expr is NULL, messages of priorities at least the notice priority will be printed.

log_out

output file.