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

mknodmake device special file

mknod [-rR] [-F fmt] [-g gid] [-m mode] name [c | b] [driver | major] minor

mknod [-rR] [-F fmt] [-g gid] [-m mode] name [c | b] major unit subunit

mknod [-rR] [-g gid] [-m mode] name [c | b] number

mknod [-rR] [-g gid] [-m mode] name p

mknod -l

The mknod command creates device special files, or fifos.

To make nodes manually, the arguments are:

Replace an existing file if its type is incorrect.
Replace an existing file if its type is incorrect. Correct the mode, user and group.
fmt
Create device nodes that may be used by an operating system which uses device numbers packed in a different format than NetBSD uses. This is necessary when NetBSD is used as an NFS server for netbooted computers running other operating systems.

The following values for the fmt are recognized: , , , , , , , , , , , , , , , and .

gid
Specify the group for the device node. The gid operand may be a numeric group ID or a group name. If a group name is also a numeric group ID, the operand is used as a group name. Precede a numeric group ID with a # to stop it being treated as a name.
mode
Specify the mode for the device node. The mode may be absolute or symbolic, see chmod(1).
name
Device name, for example “sd” for a SCSI disk on an HP300 or a “pty” for pseudo-devices.
| |
Type of device. If the device is a block type device such as a tape or disk drive which needs both cooked and raw special files, the type is b. All other devices are character type devices, such as terminal and pseudo devices, and are type c. Specifying p creates fifo files.
driver | major
The major device number is an integer number which tells the kernel which device driver entry point to use. If the device driver is configured into the current kernel it may be specified by driver name or major number.

(e.g. /usr/src/sys/arch/vax/vax/conf.c).

minor
The minor device number tells the kernel which one of several similar devices the node corresponds to; for example, it may be a specific serial port or pty.
unit and subunit
The unit and subunit numbers select a subset of a device; for example, the unit may specify a particular SCSI disk, and the subunit a partition on that disk. (Currently this form of specification is only supported by the bsdos format, for compatibility with the BSD/OS mknod).
number
A single opaque device number. Useful for netbooted computers which require device numbers packed in a format that isn't supported by -F.
List the device drivers configured into the current kernel together with their block and character major numbers.

chmod(1), mkfifo(1), mkfifo(2), mknod(2)

A mknod command appeared in Version 4 AT&T UNIX. The -F option appeared in NetBSD 1.4. The -g, -l, -m, -r, -R, and -u options, and the ability to specify a driver by name appeared in NetBSD 2.0.

September 12, 2016 macOS 15.0