Tip: quickly get help for guestfish commands

A simple tip for today. I wasn’t sure how to make a filesystem with a specified block size, so I did this:

$ guestfish -h | grep mkfs
mkfs                 make a filesystem
mkfs-b               make a filesystem with block size
$ guestfish -h mkfs-b
NAME
    mkfs-b - make a filesystem with block size

SYNOPSIS
     mkfs-b fstype blocksize device

DESCRIPTION
    This call is similar to "mkfs", but it allows you to control the block
    size of the resulting filesystem. Supported block sizes depend on the
    filesystem type, but typically they are 1024, 2048 or 4096 only.