tee - redirect command output to file

yosys> help tee

tee [-q] [-o logfile|-a logfile] cmd

Execute the specified command, optionally writing the commands output to the
specified logfile(s).

-q

Do not print output to the normal destination (console and/or log file).

-o logfile

Write output to this file, truncate if exists.

-a logfile

Write output to this file, append if exists.

-s scratchpad

Write output to this scratchpad value, truncate if it exists.

+INT, -INT
    Add/subtract INT from the -v setting for this command.