asciinema:tldr:1947d

The command "asciinema rec" is used to record a terminal session and save it as an asciicast file. An asciicast file is a text-based format that stores the input/output of a terminal session along with timing information.

When you run the "asciinema rec" command, it starts recording your terminal session. It captures all the commands that you type and the output generated by those commands. Special attention is given to timing, so even delays and pauses are preserved in the recording.

The recording continues until you manually stop it by pressing a specific key combination (usually Ctrl+D). Once you stop the recording, it is saved as an asciicast file, which can later be replayed using the "asciinema play" command.

The asciinema rec command offers a convenient way to share your terminal sessions with others. You can use it to create tutorials, demos, or simply to show someone else how to perform a set of commands in a terminal.