alertik/log.c
Davidson Francis 426ed60546 Add docs
2024-07-25 21:28:18 -03:00

119 lines
2.4 KiB
C

/*
* Alertik: a tiny 'syslog' server & notification tool for Mikrotik routers.
* This is free and unencumbered software released into the public domain.
*/
#include <fcntl.h>
#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include "events.h"
#include "log.h"
/*
* Alertik's log routines
*/
static pthread_mutex_t log_mutex = PTHREAD_MUTEX_INITIALIZER;
static int curr_file;
/* There should *always* be a corresponding close_log_file() call. */
static inline void open_log_file(void)
{
struct stat sb;
pthread_mutex_lock(&log_mutex);
if (curr_file == STDOUT_FILENO)
return;
if (stat("log", &sb) < 0) {
if (mkdir("log", 0755) < 0)
return;
}
curr_file = openat(AT_FDCWD, LOG_FILE,
O_WRONLY|O_CREAT|O_APPEND, 0666);
if (curr_file < 0)
curr_file = STDOUT_FILENO; /* fallback to stdout if can't open. */
}
/* This should *always* be called *after* a call to open_log_file(). */
static void close_log_file(void)
{
if (curr_file || curr_file == STDOUT_FILENO)
goto out;
fsync(curr_file);
close(curr_file);
out:
pthread_mutex_unlock(&log_mutex);
}
/**
* @brief Format the current time passed as @p time
* into the buffer @p time_str.
*
* @param time Time to be formated as string.
* @param time_str Output buffer.
*
* @return Returns the output buffer.
*/
char *get_formatted_time(time_t time, char *time_str)
{
strftime(
time_str,
32,
"%Y-%m-%d %H:%M:%S",
localtime(&time)
);
return time_str;
}
/**
* @brief Receives a formated string and outputs to stdout
* with the current timestamp.
*
* @param fmt String format.
*/
void log_msg(const char *fmt, ...)
{
char time_str[32] = {0};
va_list ap;
open_log_file();
dprintf(curr_file, "[%s] ", get_formatted_time(time(NULL), time_str));
va_start(ap, fmt);
vdprintf(curr_file, fmt, ap);
va_end(ap);
close_log_file();
}
/**
* @brief For a given log event @p ev, print the log event
* into the log file (wheter stdout or an actual file).
*
* @param ev Log event to be printed.
*/
void print_log_event(struct log_event *ev)
{
char time_str[32] = {0};
open_log_file();
dprintf(curr_file, "\n[%s] %s\n",
get_formatted_time(ev->timestamp, time_str), ev->msg);
close_log_file();
}
/**
* @brief Initializes the logging routines.
*/
void log_init(void) {
atexit(close_log_file);
#ifndef USE_FILE_AS_LOG
curr_file = STDOUT_FILENO;
#endif
}