utmpdump:tldr:c6465

The command "utmpdump ${-var-log-wtmp}" is a command that uses the "utmpdump" utility with a variable called "-var-log-wtmp" as an argument.

Here's a breakdown of the command:

1. "utmpdump": It is a command-line utility in Unix-like operating systems that reads and displays the contents of the utmp file. The utmp file, located in the "/var/run/" directory, contains information about currently logged-in users and their sessions.

2. "${-var-log-wtmp}": This is a variable (prefixed with a "$" sign) that represents the value "-var-log-wtmp". The purpose and meaning of this variable depend on how it is defined in the shell environment.

   • It is likely that "-var-log-wtmp" is intended to be a placeholder for the actual path to the wtmp file, which stores information about user logins, logouts, and system events. Typically, the wtmp file is located in the "/var/log/" directory.

   • The variable will be expanded to its value when the command is executed, which will result in something like "utmpdump /var/log/wtmp". This will run the "utmpdump" command on the wtmp file.

Overall, the command "utmpdump ${-var-log-wtmp}" is likely used to read and display the contents of the wtmp file using the "utmpdump" utility.