script:tldr:681be

The command "script ${logfile-log}" is invoking the Unix/Linux command "script" while passing a parameter or argument which is represented by the variable ${logfile-log}.

Here's a breakdown of the command:

• "script": It is a command available in Unix/Linux systems that allows you to make a typescript of a terminal session. It starts a new shell and records all input and output into a specified file.
• "${logfile-log}": This part represents a variable or a placeholder that holds the name of the logfile or the desired filename for the typescript. The actual value of the variable will be substituted at runtime before executing the command.

Overall, the command is executing the "script" command with the filename specified in the ${logfile-log} variable, so it will begin recording the session input and output into that file.