$ curl cheat.sh/
# grub-mkconfig
# Generate a GRUB configuration file.
# More information: <https://www.gnu.org/software/grub/manual/grub/html_node/Invoking-grub_002dmkconfig.html>.

# Do a dry run and print the configuration to `stdout`:
sudo grub-mkconfig

# Generate the configuration file:
sudo grub-mkconfig --output=/boot/grub/grub.cfg

# Print the help page:
grub-mkconfig --help

$
Follow @igor_chubin cheat.sh tldr