In Linux systems, the utmp、wtmp and btmp files play a crucial role in recording user login information. These files store binary data, so they cannot be directly edited with text editors like Vim. Instead, specific commands are used to view their contents.

utmp File

The utmp file in Linux is essential for tracking current user sessions. It contains detailed information about the active user's login, including terminal type, login time, and the device used for login. This file is vital for system administrators to monitor user activities and understand the current system usage.

Structure and Location of utmp

The utmp file is typically located in the /var/run/utmp or /var/log/wtmp directory. Its structure is defined by the C-language utmp struct, which includes multiple fields storing various user login-related data.

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