#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <stdarg.h>
#include <errno.h>
#include <string.h>

static FILE *log_fd = NULL;

void log_close() {
	fclose(log_fd);
}

void log_open(char *logfile) {
	if ((log_fd = fopen(logfile, "a" )) == NULL) {
		fprintf(stderr, "log_open(\"%s\"): %s\n", logfile, strerror(errno));
		exit(-1);
	}
	if (atexit(log_close) != 0) {
		fprintf(stderr, "log_open(): atexit(): %s\n", strerror(errno));
		exit(-1);
	}
}

void log_print(const char *fmt, ...) {
	va_list az;
	time_t  tzgr;
	char    tbuf[64];
	char    buffer[256];

	va_start(az, fmt);
	vsprintf(buffer, fmt, az);
	va_end(az);

	time(&tzgr);
	strftime(tbuf, 64, "%b %d %H:%M:%S :", localtime(&tzgr));

	if (log_fd) {
		if (errno) {
			fprintf(log_fd, "%s %s: %s\n", tbuf, buffer, strerror(errno));
		} else {
			fprintf(log_fd, "%s %s\n", tbuf, buffer);
		}
	} else {
		if (errno) {
			fprintf(stderr, "%s %s: %s\n", tbuf, buffer, strerror(errno));
		} else {
			fprintf(stderr, "%s %s\n", tbuf, buffer);
		}
	}
	errno = 0;
	fflush(log_fd);
}