mkfs.ext4dev -VERSION (return code: 0)
mke2fs 1.42.13 (17-May-2015)
Using EXT2FS Library version 1.42.13
mkfs.ext4dev --help (return code: 1)
mkfs.ext4dev: invalid option -- '-'
Usage: mkfs.ext4dev [-c|-l filename] [-b block-size] [-C cluster-size]
[-i bytes-per-inode] [-I inode-size] [-J journal-options]
[-G flex-group-size] [-N number-of-inodes]
[-m reserved-blocks-percentage] [-o creator-os]
[-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
[-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
[-t fs-type] [-T usage-type ] [-U UUID] [-jnqvDFKSV] device [blocks-count]