Is it possible to save output from a command to a file after the command already has been executed?

You appear to have a number of options, but gnome-terminal doesn't support logging to a file by itself.

• You can run the script command before your output in order to accomplish this. See this Launchapd Q&A for more.

• You can install and use a different terminal instead of gnome-terminal, which supports logging all output to a file, such as Putty. There may be others.

• You can simply highlight the text output you require, then use CTRL-SHIFT-C to copy the text.

If you are looking for a way to save the output of a command in a file and also display it in the terminal, then use tee command.

command | tee filename

output of the command is displayed in the terminal as well as in the file.