cschlosser / glog-rs

Port of the C++ glog logging functionality as backend into the standard Rust logging frontend

glog for Rust

This is a port of the C++ logging framework glog as backend for Rusts standard logging frontend.

⚠️ Stability Warning: Currently there are no tests for this framework. This will be added in the next release. Currently the framework is tested only manually to verify the current featureset.

Introduction

glog-rs tries to stay as close to glog as possible to maintain compatibility, which can be useful in mixed environments using C++ and Rust code at the same time.

This includes default values for flags, flag names and behavior.

Additional options or configurations can be enabled before initializing the framework to use more of what the Rust standard logging frontend has to offer or to solve different use cases.

Examples

The most basic example is this:

use log::*;
use glog::Flags;

glog::new().init(Flags::default()).unwrap();

info!("It works!");

which will write I0401 12:34:56.987654 123 readme.rs:6] It works! to the INFO log file.

If you want to have colored output on stderr as well consider initializing by using some of the flags:

glog::new().init(Flags {
        colorlogtostderr: true,
        alsologtostderr: true, // use logtostderr to only write to stderr and not to files
        ..Default::default()
    }).unwrap();

A non standard extension would the year in addition to month and day in the timestamp. This is possible by calling the with_year method prior to init like this:

glog::new()
    .with_year(true) // Add the year to the timestamp in the logfile
    .init(Flags {
        logtostderr: true, // don't write to log files
        ..Default::default()
    }).unwrap();

info!("With the year");

will print I20210401 12:34:56.987654 123 readme.rs:11] With the year.

Inspirations

This project was inspired by the great C++ logging framework glog and stderrlog-rs as a kickstarter for a Rust logging backend.

glog-rs's Issues

Write a helpful README

Change logging level during runtime

Add tests

Can `std::env::temp_dir` return an empty string?

Add documentation

Add `verbose!` log level

Have access to Windows API working

Windows uses its own way of exposing its API.
This needs some additional work.

Add `fatal!` log level

Generate convenient symlinks to latest log files.

The C++ library has a helper SetLogSymlink and the Go version automatically creates symlinks for each log file.

So, for example, on my system I see files like this from a Go program using glog:

$ ls -l /tmp/nomadnet.INFO         
lrwxrwxrwx 1 wathiede users 59 Dec 26 21:16 /tmp/nomadnet.INFO -> nomadnet.nixos-07.wathiede.log.INFO.20221226-211600.4192921

That points to the logs of the most recent invocations of my glog enabled programs.

Would you be receptive of a pull request that mimicked the Go behavior? If not, how about a helper to create it manually like the C++ version?

The automatic behavior is really nice because the symlinks don't get created until a program has logged at that level, for example, the .ERROR symlink won't even exist if the program hasn't yet logged at the error level.

Add a changelog

Add option for logging in UTC