Tmux

In the context of this file, the key combo Prefix will be used to denote the combination configured as the bind key in the tmux configuration. By default, this is ^B Shift+:.

Copying Text from Buffer to File

Where lines is the number of lines to save in the buffer, and file-path is an absolute file path or a relative path (in which case it will be assumed relative to the working directory of the tmux server).

Prefix capture-pane -S -<lines>
Prefix save-buffer <file-path>