grub-editenv [,OPTION/...] ,FILENAME COMMAND/
Tool to edit environment block.
If FILENAME is `-', the default value ,/boot/grub/grubenv/ is used.
There is no `delete' command; if you want to delete the whole environment block, use `rm /boot/grub/grubenv'.
Report bugs to <email@example.com>.
The full documentation for grub-editenv is maintained as a Texinfo manual. If the info and grub-editenv programs are properly installed at your site, the command
should give you access to the complete manual.