The logger command allows scripts to create and manage log messages:

1. Place a message in the syslog file /var/log/messages:

        $ logger LOG_MESSAGE

Consider this example:

        $ logger This is a test log line

        $ tail -n 1 /var/log/messages
        Sep 29 07:47:44 slynux-laptop slynux: This is a test log line

The /var/log/messages log file is a general purpose log file. When the logger command is used, it logs to /var/log/messages by default.

2. The -t flag defines a tag for the message:

        $ logger -t TAG This is a message

        $ tail -n 1 /var/log/messages
        Sep 29 07:48:42 slynux-laptop TAG: This is a message

The -p option to logger and configuration files in /etc/rsyslog.d control where log messages are saved.

To save to a custom file, follow these steps:

Consider the following example:

        # cat /etc/rsyslog.d/myConfig
        local7.* /var/log/local7
        # cd /etc/init.d
        # ./syslogd restart
        # logger -p local7.info A line to be placed in /var/log/local7

3. The -f option will log the lines from another file:

        $ logger -f /var/log/source.log