log.c

Go to the documentation of this file.

 
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
 
#include "log.h"
 
static char log_filename[RL_LOG_PATH_LENGTH_MAX] = RL_LOG_DEFAULT_FILE;
 
static rl_log_level_t log_verbosity = RL_LOG_VERBOSE;
 
int rl_log_init(char const *const log_file, rl_log_level_t verbosity) {
    // update log configuration
    rl_log_verbosity(verbosity);
    strncpy(log_filename, log_file, sizeof(log_filename) - 1);
 
    // open log file (create inexistent) to check for max file size
    FILE *log_fp = fopen(log_filename, "a");
    if (log_fp == NULL) {
        printf("Error: failed to open log file\n");
        return -1;
    }
 
    // reset the log file if it is getting large
    if (ftell(log_fp) > RL_LOG_FILE_SIZE_MAX) {
        log_fp = freopen(log_filename, "w", log_fp);
        if (log_fp == NULL) {
            printf("Error: failed to reset log file size\n");
            return -1;
        }
    }
 
    // write header for new (empty) file, or empty line for existing file
    if (ftell(log_fp) == 0) {
        fprintf(log_fp, "# RocketLogger Log File\n");
    }
 
    // close log file
    fclose(log_fp);
    return 0;
}
 
void rl_log_verbosity(rl_log_level_t verbosity) { log_verbosity = verbosity; }
 
int rl_log(rl_log_level_t log_level, char const *const format, ...) {
    // do not handle ignore log level
    if (log_level == RL_LOG_IGNORE) {
        return 0;
    }
 
    // log only if log level is equal or higher than configured verbosity
    if (log_level > log_verbosity) {
        return 0;
    }
 
    // get arguments
    va_list args;
    va_start(args, format);
 
    // get current time
    time_t time_raw;
    struct tm *time_info;
    char time_str[24];
 
    time(&time_raw);
    time_info = gmtime(&time_raw);
    strftime(time_str, sizeof(time_str), "%F %T\t", time_info);
 
    // open log file
    FILE *log_fp = fopen(log_filename, "a");
    if (log_fp == NULL) {
        printf("Error: failed to open log file\n");
        return -1;
    }
 
    // write time, log level, and message to log file
    fprintf(log_fp, "%s", time_str);
    switch (log_level) {
    case RL_LOG_ERROR:
        fprintf(log_fp, "ERROR\t");
        break;
    case RL_LOG_WARNING:
        fprintf(log_fp, "WARN\t");
        break;
    case RL_LOG_INFO:
        fprintf(log_fp, "INFO\t");
        break;
    case RL_LOG_VERBOSE:
        fprintf(log_fp, "VERB\t");
        break;
    default:
        // for debugging purposes
        fprintf(log_fp, "N/A\t");
        printf("Error: unsupported log level with message:\n  ");
        break;
    }
    vfprintf(log_fp, format, args);
    fprintf(log_fp, "\n");
 
    // close file
    fclose(log_fp);
 
    // output to terminal
    switch (log_level) {
    case RL_LOG_ERROR:
        printf("Error: ");
        break;
    case RL_LOG_WARNING:
        printf("Warning: ");
        break;
    case RL_LOG_INFO:
        printf("Info: ");
        break;
    case RL_LOG_VERBOSE:
        printf("Verbose: ");
        break;
    default:
        // skip handled above
        break;
    }
    vprintf(format, args);
    printf("\n");
 
    // facilitate return
    va_end(args);
 
    return 0;
}