single c header colorful logger. base on https://github.com/zakird/zdlibc/blob/master/logger.h.

logger.h

#include <stdio.h>
#include <stdarg.h>

#ifndef HEADER_SINGLELIBC_LOGGER_H
#define HEADER_SINGLELIBC_LOGGER_H

#include <stdlib.h>
#include <stdio.h>
#include <sys/time.h>
#include <math.h>

#define CL_NONE                 "\e[0m"
#define CL_FATAL                "\e[1;31m"
#define CL_ERROR                "\e[1;35m"
#define CL_WARN                 "\e[1;33m"
#define CL_INFO                 "\e[1;36m"
#define CL_DEBUG                "\e[1;32m"
#define CL_TRACE                "\e[1;37m"

enum LogLevel {
    LOG_LEVEL_FATAL, LOG_LEVEL_ERROR, LOG_LEVEL_WARN, LOG_LEVEL_INFO, LOG_LEVEL_DEBUG, LOG_LEVEL_TRACE
};


int log_init(FILE *stream, enum LogLevel level);

int log_error(const char *log_name, const char *log_msg, ...);

int log_warn(const char *log_name, const char *log_msg, ...);

int log_info(const char *log_name, const char *log_msg, ...);

int log_debug(const char *log_name, const char *log_msg, ...);

static enum LogLevel log_output_level = LOG_LEVEL_INFO;

static FILE *log_output_stream = NULL;

static char *log_level_name[] = {"FATAL", "ERROR", "WARN", "INFO", "DEBUG", "TRACE"};
static char *log_level_color[] = {CL_FATAL, CL_ERROR, CL_WARN, CL_INFO, CL_DEBUG, CL_TRACE};

static int LogLogVA(enum LogLevel level, const char *name, const char *message, va_list args) {
    if (!log_output_stream) {
        log_output_stream = stdout;
    }
    if (level <= log_output_level) {
        char *level_name = log_level_name[level];
        char *level_color = log_level_color[level];

        struct timeval now;
        char timestamp[20];
        gettimeofday(&now, NULL);
        time_t sec = now.tv_sec;
        struct tm *ptm = localtime(&sec);
        strftime(timestamp, 20, "%FT%H:%M:%S", ptm);
        if (log_output_stream == stdout) {
            fputs(level_color, log_output_stream);
        }
        // ISO_8601
        fprintf(log_output_stream, "[%s.%03ldZ][%s]", timestamp, (long) (now.tv_usec / 1000), level_name);
        if (name) {
            fprintf(log_output_stream, "[%s] - ", name);
        }
        if (message) {
            vfprintf(log_output_stream, message, args);
        }
        if (log_output_stream == stdout) {
            fputs(CL_NONE, log_output_stream);
        }
        if (name || message) {
            fputs("\n", log_output_stream);
        }
    }
    return 0;
}

int log_init(FILE *stream, enum LogLevel level) {
    log_output_stream = stream;
    log_output_level = level;
    return 0;
}

int log_error(const char *name, const char *message, ...) {
    va_list va;
    va_start(va, message);
    int ret = LogLogVA(LOG_LEVEL_ERROR, name, message, va);
    va_end(va);
    return ret;
}

int log_warn(const char *name, const char *message, ...) {
    va_list va;
    va_start(va, message);
    int ret = LogLogVA(LOG_LEVEL_WARN, name, message, va);
    va_end(va);
    return ret;
}

int log_info(const char *name, const char *message, ...) {
    va_list va;
    va_start(va, message);
    int ret = LogLogVA(LOG_LEVEL_INFO, name, message, va);
    va_end(va);
    return ret;
}

int log_debug(const char *name, const char *message, ...) {
    va_list va;
    va_start(va, message);
    int ret = LogLogVA(LOG_LEVEL_DEBUG, name, message, va);
    va_end(va);
    return ret;
}

#endif//HEADER_SINGLELIBC_LOGGER_H

without bold font

#define CL_NONE                 "\e[0m"
#define CL_FATAL                "\e[31m"
#define CL_ERROR                "\e[35m"
#define CL_WARN                 "\e[33m"
#define CL_INFO                 "\e[36m"
#define CL_DEBUG                "\e[32m"
#define CL_TRACE                "\e[37m"