MKNOD(8)

NAME
mknod - build special file

SYNOPSIS
mknod name [c | b] major minor [owner:group]

DESCRIPTION
The mknod command creates device special files. Normally the shell script /dev/MAKEDEV is used to create special files for commonly known devices; it executes mknod with the appropriate arguments and can make all the files required for the device.

To make nodes manually, the four required arguments are:

name
    Device name, for example “sd” for a SCSI disk on an HP300 or a “pty” for pseudo-devices.

b | c
    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.

major
    The major device number is an integer number which tells the kernel which device driver entry point to use. To learn what major device number to use for a particular device, check the file /dev/MAKEDEV to see if the device is known, or check the system dependent device configuration file:

    “/usr/src/sys/conf/device.architecture”

    (for example device.hp300).

minor
    The minor device number tells the kernel which subunit the node corresponds to on the device; for example, a subunit may be a filesystem partition or a tty line.

owner  group
    The owner group operand pair is optional, however, if one is specified, they both must be specified. The owner may be either a numeric user ID or a user name. If a user name is also a numeric user ID, the operand is used as a user name. The group may be either a numeric group ID or a group name. Similar to the user name, if a group name is also a numeric group ID, the operand is used as a group name.

Major and minor device numbers can be given in any format acceptable to strtoul(3), so that a leading ‘0x’ indicates a hexadecimal number, and a leading ‘0’ will cause the number to be interpreted as octal.

COMPATIBILITY
The chown(8) like functionality is specific to FreeBSD and was added so that /dev/MAKEDEV wound not depend on /usr being mounted.

SEE ALSO
mkfifo(1), mknod(2), MAKEDEV(8), chown(8)

HISTORY
A mknod command appeared in AT&T UNIX.