logger

Minimal Clojure logging library, mainly for scripting

Why?

There are quite a few logging libraries already available, so why another one? Some goals:

• Log both to a file and to the console (stdout for now)
• Include timestamps with both milliseconds and timezone
• No config files needed
• Keep it simple, mostly for command line scripts
• Support multiple log files, e.g. server/daemon and client/script logs.

Installation

Leiningen/Boot

[ndevreeze/logger "0.4.0"]

Clojure CLI/deps.edn

ndevreeze/logger {:mvn/version "0.4.0"}

Usage

Require:

(ns my.namespace
  (:require [ndevreeze.logger :as log]))

Initialise the logger:

(log/init "/tmp/foo.log" :info)

or, to only log to stderr:

(log/init nil :debug)

or, init with a map, with these keys:

• level - log level like :info, :debug
• file - give an explicit full path. Default is nil, use pattern
• pattern - use a pattern for the log file path, see below
• location - some pattern defaults/shortcuts, :home, :cwd, :script, :temp, default is nil
• name - script name, "script" bij default
• cwd - give an explicit current-working-dir, default is nil
• overwrite - boolean, overwrite an existing log file, default false

if all of file, pattern and location are nil, do not create a logfile, just log to the console.

To use in pattern:

• %h = home dir
• %c = current dir
• %s = script dir (TBD)
• %t = temp dir (/tmp, or c:/tmp)
• %n = script name
• %d = datetime, as yyyy-mm-ddTHH-MM-SS"

Then log at different levels:

(log/error "A different logfile, error level")
(log/warn "warn level")
(log/debug "One line at debug level")
(log/info "At info level")

Developing

Testing

$ lein midje

or:

$ lein repl (or start in Cider)
(use 'midje.repl)
(autotest)

Bugs

• No known errors, but see Todo below. Use Github issues if you want to report a bug.

Todo

• Should use Log4j v2, now using v1.

Related and similar projects (libraries)

• https://github.com/pjlegato/onelog - used as a base for this library, but some differences.
• https://github.com/malcolmsparks/clj-logging-config - also used as a base

License

Copyright © 2020, 2021 Nico de Vreeze

Distributed under the Eclipse Public License, the same as Clojure.