Log4cl is a log library for Common Lisp.
Log4cl is based on log4j

Log4cl is developed on Debian GNU/Linux , and has been tested under CMUCL and SBCL
It is licensed under a license Lisp Lesser GNU Public License

A logger can have multiple appenders. Theses appenders defined differents methods for logging message. Currently theses appenders are implemented :

• console-appender : log message to the default exit
• syslog-appender : use syslog for logging
• file-appender : log message into a file
• rolling-file-appender : log message into a file. If size of the file is greater than the max size, we create an archive of the current file, and a new file for logging message
• daily-rolling-file-appender : log message into a file named by the current date. If log file is a previous date, a new file is created
• db-appender : Log a message with into a Mysql or PostgreSQL database
  For Mysql, Table must have this structure :
  
  

  +---------+--------------+------+-----+---------+----------------+
  | Field   | Type         | Null | Key | Default | Extra          |
  +---------+--------------+------+-----+---------+----------------+
  | id      | int(16)      |      | PRI | NULL    | auto_increment |
  | level   | varchar(10)  |      | MUL |         |                |
  | message | varchar(255) |      |     |         |                |
  +---------+--------------+------+-----+---------+----------------+
      

  
  For PostgreSQL , Table must have this structure :
  
  

   Colonne |  Type   |                    Modifications                     
  ---------+---------+------------------------------------------------------
   id      | integer | not null default nextval('public.logs_id_seq'::text)
   level   | text    | not null
   message | text    | not null
  Index: logs_pkey primary key btree (id),
         logs_level_key btree ("level")
      

Appender have on layout, which defined the output of the message

• simple-layout : write the name of the application, the level of log and the messsage.
• pattern-layout : a customizable layout
• html-layout : log message with HTML

There are five levels of logging in log4cl : debug, info, warning, error and fatal.
It is possible to add or remove levels of a logger

Use :

USER> (asdf:operate 'asdf:load-op 'log4cl)

USER> (in-package :log4cl)

LOG4CL> (setf new-logger (make-instance 'logger))

LOG4CL> (setf app-console (make-instance 'console-appender))

LOG4CL> (add-appender new-logger app-console)

LOG4CL> (log-debug new-logger " a log message ")
 logger : [ERROR]  a log message  

LOG4CL> (log-debug new-logger " a log message ")
 logger : [ERROR]  a log message  

And : 

$>more /tmp/log-test.log
logger : [ERROR]  a log message