The Grub console

Tab : display available commands
help command : display help for that command if available ,
If not available "insmod command" is needed to load the command.mod
ex : "insmod date" then "help date"

grub2 switches between 2 modes of "shell console"

a sh:grub> activated by typing "reader.normal"
b grub_rescue> mode activated by typing "reader.rescue"

A 3rd lua.console> can be turned on from normal sh:grub
c lua:grub> mode activated by typing "parser.lua" ; use """) to switch back to sh:grub>

configfile switch to another config
source load another config -without changing config-

sh:grub requires the following modules : sh normal minicmd which come up with kernel.img