Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
MKNOD(8)		  BSD System Manager's Manual		      MKNOD(8)

     mknod -- build special file

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

     The mknod utility is deprecated on	modern FreeBSD systems.

     The mknod utility creates device special files.  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-terminals.

     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 ker-
	     nel which device driver entry point to use.  To learn what	major
	     device number to use for a	particular device, check

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

	     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 nu-
	     meric 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	oper-
	     and 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.

     The mknod utility can be used to recreate deleted device nodes under a
     devfs(5) mount point by invoking it using dummy arguments.	 Example:

	   mknod cd0 c 0 0

     where "cd0" is the	name of	the deleted device node.

     The chown(8)-like functionality is	specific to FreeBSD.

     As	of FreeBSD 4.0,	block devices were deprecated in favour	of character
     devices.  As of FreeBSD 5.0, device nodes are managed by the device file
     system devfs(5), making the mknod utility superfluous.  As	of FreeBSD 6.0
     device nodes may be created in regular file systems but such nodes	cannot
     be	used to	access devices.

     mkfifo(1),	mknod(2), devfs(5), chown(8)

     A mknod utility appeared in Version 6 AT&T	UNIX.

BSD			       December	15, 2004			   BSD


Want to link to this manual page? Use this URL:

home | help