Ubuntu is one of the most widely used Linux-based operating systems, known for its fast, secure and user-friendly features. One of the many benefits that come with Ubuntu is the ability to access system log files to gather information, troubleshoot errors, and monitor system activity.

In this article, we will look at how you can view and write to system log files on Ubuntu.

Viewing System Log Files:

The system log files in Ubuntu are located in the /var/log directory, which holds various log files created by system services and applications. The log files are divided into categories to make it easier to identify the logs that you need to access.

To view the system log files, open the terminal by pressing Ctrl+Alt+T key combinations. Once the terminal is open, enter the following command:

sudo cat/var/log/syslog

This command will display the content of the syslog file on the terminal screen, allowing you to read through the log files.

Similarly, there are several other system log files that you can access by running commands such as sudo cat/var/log/dmesg, sudo cat/var/log/kern.log and sudo cat/var/log/messages, depending on the log files you want to access.

Writing to System Log Files:

While viewing the system log files can be helpful, sometimes it’s not enough to solve the issues you are facing. In such cases, you may need to write to system log files to add relevant information about the issue you wish to report.

To write to a system log file, use the ‘logger’ command with the -p option followed by the priority code and the message you want to add to the log file. The priority codes are as follows:

0 Emergencies: System is unusable

1 Alerts: Action must be taken immediately

2 Critical: Critical conditions

3 Errors: Error conditions

4 Warnings: Warning conditions

5 Notices: Normal but significant conditions

6 Informational: Informational messages

7 Debugging: Debugging messages

For example, to write to the syslog file at the debug level, run the command:

sudo logger -p debug “Test message for syslog”

This will write the message “Test message for syslog” to the syslog file at the debug level.

In conclusion, accessing system log files can help you to troubleshoot and solve issues related to your Ubuntu system. With the above commands, you can easily view and write to system log files. These commands can also be combined with other tools to create automated scripts for system monitoring and maintenance. Remember that not all log files are equal, and you need to understand what each log file contains to diagnose an issue accurately. Also, while writing to log files can be helpful, you should be careful not to flood the log files with unnecessary messages that might make it difficult to interpret relevant information.