Essential System Tools: journalctl – query and display messages from the journal

journalctl is used for querying and displaying messages from the journal. Since the journal comprises of one or more binary files, journalctl is the standard way to read messages from it. This is the eighth in our series of articles highlighting essential system tools. These are small utilities, useful for system administrators as well as regular users of Linux based systems. The series examines both graphical and text based open source utilities. For this article, we’ll examine journalctl.