Can you add support for colored output to console?

[jdukat]

Linux shell and Windows10 console output can be colorized in a standard way. Can you add support and configurability for this?

[moritzhoewer]

You can use the #define ELPP_CUSTOM_COUT_LINE(msg) as a workaround

add a helper-method like this somewhere in your code

// Colors for output
#define RESET "\033[0m"
#define RED "\033[31m"
#define ORANGE "\033[33m"
#define GRAY "\033[90m"

std::string make_coloured(std::string msg){
    std::string prefix = msg.substr(0, 7);
    if(prefix == "[ERROR]"){
        msg = RED + msg + RESET;
    } else if(prefix == "[WARN ]"){
        msg = ORANGE + msg + RESET;
    } else if(prefix == "[TRACE]"){
        msg = GRAY + msg + RESET;
    }
    return msg;
}

and then before you #include "easylogging++.h" you do
#define ELPP_CUSTOM_COUT_LINE(msg) make_coloured(msg)
My log messages start with [%level], so I can use that to get the logging level in my helper function.

I had some more options to set before the #include, and it started getting messy so I just put it all in a "custom header" and included that instead of "easylogging++.h"

#ifndef CUSTOM_EASYLOGGING_H
#define CUSTOM_EASYLOGGING_H

// declare my custom output method
std::string make_coloured(std::string msg);

// easylogging options
#define ELPP_CUSTOM_COUT_LINE(msg) make_coloured(msg)
#define ELPP_DISABLE_DEFAULT_CRASH_HANDLING

// include actual easylogging
#include "easylogging++.h"

// initialize
INITIALIZE_EASYLOGGINGPP

#endif //CUSTOM_EASYLOGGING_H

[chausner]

Version 9.26 introduced inbuilt support for this via the LoggingFlag::ColoredTerminalOutput setting. However, the colors for the different log levels are currently hardcoded and cannot be changed. Also, it appears to target Linux terminals and Cygwin and does not work out-of-the-box with Windows Terminal yet. So the above approach may still be a viable alternative, depending on your needs.

I opened a PR to improve the compatibility on Windows: #843