log.c

#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <stdarg.h>
#include <time.h>

#include "log.h"

int g_verbosity = VERBOSITY_VERBOSE;
int g_use_syslog = 0;
#define MAIN_SRVNAME ""

#ifdef DEBUG

// Program start time
static struct timespec log_start = { 0, 0 };

const char *log_time() {
	struct timespec now = { 0, 0 };
	clock_gettime( CLOCK_MONOTONIC, &now );

	// Initialize clock
	if( log_start.tv_sec == 0 && log_start.tv_nsec == 0 ) {
		clock_gettime( CLOCK_MONOTONIC, &log_start );
	}

	static char buf[10];
	sprintf( buf, "[%8.2f] ",
		((double) now.tv_sec + 1.0e-9 * now.tv_nsec) -
		((double) log_start.tv_sec + 1.0e-9 * log_start.tv_nsec)
	);

	return buf;
}

#endif

void log_print( int priority, const char format[], ... ) {
	char buf[1024];
	//const char *prefix;
	const char *time;
	va_list vlist;

	va_start( vlist, format );
	vsnprintf( buf, sizeof(buf), format, vlist );
	va_end( vlist );

#ifdef DEBUG
	time = log_time();
#else
	time = "";
#endif

	if( g_use_syslog ) {
		// Write messages to e.g. /var/log/syslog
		openlog( MAIN_SRVNAME, LOG_PID | LOG_CONS, LOG_USER | LOG_PERROR );
		syslog( priority, "%s%s", time, buf );
		closelog();
	} else {
		FILE *out = (priority == LOG_ERR) ? stderr : stdout;
		fprintf( out, "%s %s\n", time, buf );
	}
}