xref: /freebsd/sbin/mknod/mknod.8 (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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28.\"     @(#)mknod.8	8.2 (Berkeley) 12/11/93
29.\" $FreeBSD$
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31.Dd December 15, 2004
32.Dt MKNOD 8
33.Os
34.Sh NAME
35.Nm mknod
36.Nd build special file
37.Sh SYNOPSIS
38.Nm
39.Ar name
40.Op Cm b | c
41.Ar major minor
42.Op Ar owner : Ns Ar group
43.Sh DESCRIPTION
44.Bf -symbolic
45The
46.Nm
47utility is deprecated on modern
48.Fx
49systems.
50.Ef
51.Pp
52The
53.Nm
54utility creates device special files.
55To make nodes manually, the four required arguments are:
56.Pp
57.Bl -tag -width indent
58.It Ar name
59Device name, for example
60.Dq sd
61for a SCSI disk on an HP300 or a
62.Dq pty
63for pseudo-terminals.
64.It Cm b | c
65Type of device.
66If the
67device is a block type device such as a tape or disk drive which needs
68both cooked and raw special files,
69the type is
70.Cm b .
71All other devices are character type devices, such as terminal
72and pseudo devices, and are type
73.Cm c .
74.It Ar major
75The major device number is an integer number which tells the kernel
76which device driver entry point to use.
77To learn what
78major device number to use for a particular device, check
79.Pa /usr/src/sys/conf/majors .
80.It Ar minor
81The minor device number tells the kernel which subunit
82the node corresponds to on the device; for example,
83a subunit may be a file system partition
84or a tty line.
85.It Ar owner : Ns Ar group
86The
87.Ar owner
88.Ar group
89operand pair is optional, however, if one is specified, they both must be
90specified.
91The
92.Ar owner
93may be either a numeric user ID or a user name.
94If a user name is also a numeric user ID, the operand is used as a
95user name.
96The
97.Ar group
98may be either a numeric group ID or a group name.
99Similar to the user name,
100if a group name is also a numeric group ID, the operand is used as a
101group name.
102.El
103.Pp
104Major and minor device numbers can be given in any format acceptable to
105.Xr strtoul 3 ,
106so that a leading
107.Ql 0x
108indicates a hexadecimal number, and a leading
109.Ql 0
110will cause the number to be interpreted as octal.
111.Pp
112The
113.Nm
114utility can be used to recreate deleted device nodes under a
115.Xr devfs 5
116mount point by invoking it using dummy arguments.
117Example:
118.Pp
119.Dl "mknod cd0 c 0 0"
120.Pp
121where
122.Dq Li cd0
123is the name of the deleted device node.
124.Sh COMPATIBILITY
125The
126.Xr chown 8 Ns - Ns
127like functionality is specific to
128.Fx .
129.Pp
130As of
131.Fx 4.0 ,
132block devices were deprecated in favour of character
133devices.
134As of
135.Fx 5.0 ,
136device nodes are managed by the device file system
137.Xr devfs 5 ,
138making the
139.Nm
140utility superfluous.
141As of
142.Fx 6.0
143device nodes may be created in regular file systems but such
144nodes cannot be used to access devices.
145.Sh SEE ALSO
146.Xr mkfifo 1 ,
147.Xr mknod 2 ,
148.Xr devfs 5 ,
149.Xr chown 8
150.Sh HISTORY
151A
152.Nm
153utility appeared in
154.At v6 .
155