New user: forcing programme exit when spdlog::error is called

[a-jp]

Hi,
I'm a new user. I would like to ensure I can trigger a programme stop when/if I send anything to the error stream as this is the way I would like my programme to function. I have quite a simple set up:

    spdlog::set_level(spdlog::level::debug); // Set global log level to debug

    spdlog::set_error_handler([](const std::string &msg) {
        throw std::runtime_error(msg);
    });

   spdlog::error("Something failed");

However, the programme continues to run after this statement. Can anyone help me get this working?
Thanks,
Andy

[gabime]

set_error_ handler is not for this purpose. it is called when there is a problem in the logging itself(e.g. fail write to log file).

Please see #1328 on how to achieve this.

[a-jp]

Thanks, is there any chance you could provide a small example including how to add a sink? I'm quite new to the library and not really sure how to do that or when is the correct point to inject the new sink? I have looked at the wiki and the sinks folder. Thanks again.

[tt4g]

@a-jp For your example (NOTICE It has not been confirmed that it works):

#include "spdlog/base_sink.h"
#include "spdlog/details/log_msg.h"
#include "spdlog/details/null_mutex.h"

#include <memory>
#include <mutex>
#include <string>

template<typename Mutex>
class error_proxy_sink : public spdlog::sinks::base_sink<Mutex>
{
    using BaseSink = spdlog::sinks::base_sink<Mutex>;

    std::shared_ptr<spdlog::sinks::sink> sink_;

public:

    explicit error_proxy_sink(
        std::shared_ptr<spdlog::sinks::sink> sink)
        : sink_(sink)
    {

    }

    error_proxy_sink(const error_proxy_sink&) = delete;
    error_proxy_sink& operator=(const error_proxy_sink&) = delete;

protected:
    void sink_it_(const spdlog::details::log_msg &msg) override
    {
        if (spdlog::level::err == msg.level)
        {
             // Call your error callback.
        }

        if (sink_->should_log(msg.level))
        {
            sink_->log(msg);
        }
    }

    void flush_() override
    {
        sink_->flush();
    }

    void set_pattern_(const std::string &pattern) override
    {
        set_formatter_(spdlog::details::make_unique<spdlog::pattern_formatter>(pattern));
    }

    void set_formatter_(std::unique_ptr<spdlog::formatter> sink_formatter) override
    {
        BaseSink::formatter_ = std::move(sink_formatter);

        sink_->set_formatter(BaseSink::formatter_->clone());
    }
};

using error_proxy_sink_mt = error_proxy_sink<std::mutex>;
using error_proxy_sink_st = error_proxy_sink<spdlog::details::null_mutex>;

Usage:

#include "spdlog/spdlog.h"
#include "spdlog/sinks/stdout_sinks.h"

#include <memory>

int main(int, char*)
{
    auto console_sink = std::make_shared<stdout_sink_mt>();
    auto do_on_error_sink = std::make_shared<error_proxy_sink_mt>(console_sink);

    auto logger = std::make_shared<spdlog::logger>("console_with_do_on_error", do_on_error_sink);
    spdlog::register_logger(logger);

    logger->info("foo");
    logger->error("bar");
    logger->error("baz");

    spdlog::shutdown();

    return 0;
}

See also:

• https://github.com/gabime/spdlog/blob/v1.4.2/include/spdlog/sinks/dist_sink.h
• https://github.com/gabime/spdlog/blob/v1.4.2/include/spdlog/sinks/sink-inl.h
• https://github.com/gabime/spdlog/blob/v1.4.2/include/spdlog/sinks/base_sink.h

[a-jp]

thank you