Syslog

Syslog is a standard for computer data logging. It separates the software that generates messages from the system that stores them and the software that reports and analyzes them.

Syslog can be used for computer system management and security auditing as well as generalized informational, analysis, and debugging messages. It is supported by a wide variety of devices (like printers and routers) and receivers across multiple platforms. Because of this, syslog can be used to integrate log data from many different types of systems into a central repository.

Messages are labeled with a facility code (auth, authpriv, daemon, cron, ftp, lpr, kern, mail, news, syslog, user, uucp, local0, ..., local7) indicating the type of software that generated the messages, and are assigned a severity (Emergency, Alert, Critical, Error, Warning, Notice, Info, Debug).

Implementations are available for many operating systems. Specific configuration may permit directing messages to various devices (console), files (/var/log/) or remote syslog servers. Most implementations also provide a command line utility, often called logger, that can send messages to the syslog. Some implementations permit the filtering and display of syslog messages.

Syslog is now standardized within the Syslog working group of the IETF.