FSTYP(8) System Manager's Manual FSTYP(8)

fstyp — determine file system type

fstyp [-lsu] special

The fstyp utility is used to determine the file system type on a given device. It can recognize ISO-9660, exFAT, Ext2, FAT, NTFS, UFS, HAMMER, and HAMMER2 file systems. When the -u flag is specified, fstyp also recognizes certain additional metadata formats that cannot be handled using mount(8), such as ZFS pools.

The file system name is printed to the standard output as, respectively:

Note that a HAMMER file system consisting of more than one volume requires a path in blkdevs format.

Because fstyp is built specifically to detect file system types, it differs from file(1) in several ways. The output is machine-parsable, file system labels are supported, and it does not try to recognize any file format other than file systems.

These options are available:

In addition to file system type, print file system label if available.
Ignore file type. By default, fstyp only works on regular files and disk-like device nodes. Trying to read other file types might have unexpected consequences or hang indefinitely.
Include file systems and devices that cannot be mounted directly by mount(8).

The fstyp utility exits 0 on success, and >0 if an error occurs or the file system type is not recognized.

file(1), autofs(5), mount(8), zpool(8)

The fstyp command appeared in FreeBSD 10.2. The fstyp command appeared in DragonFly 4.5. The fstyp command appeared in NetBSD 9.0.

The fstyp utility was developed by Edward Tomasz Napierala <trasz@FreeBSD.org> under sponsorship from the FreeBSD Foundation. ZFS and GELI support was added by Allan Jude <allanjude@FreeBSD.org>.

The fstyp utility was ported to DragonFly and NetBSD by Tomohiro Kusumi <tkusumi@netbsd.org>.

geli and hammer are currently unsupported on NetBSD.

January 1, 2020 NetBSD 11.0