2.9BSD/usr/man/man2/mknod.2

.TH MKNOD 2 
.UC
.SH NAME
mknod \- make a directory or a special file
.SH SYNOPSIS
.B mknod(name, mode, addr)
.br
.B char *name;
.SH DESCRIPTION
.I Mknod
creates a new file
whose name is the null-terminated string pointed
to by
.IR name .
The mode of the new file
(including directory and special file bits)
is initialized from
.IR mode .
(The protection part of the mode
is modified by the process's mode mask; see
.IR umask (2)).
The first block pointer of the i-node
is initialized from
.IR addr .
For ordinary files and directories
.I addr
is normally zero.
In the case of a special file,
.I addr
specifies which special file.
.PP
.I Mknod
may be invoked only by the super-user.
.SH RETURN VALUE
Upon successful completion, a value of 0 is returned.  Otherwise, a
value of \-1 is returned and
.I errno
is set to indicate the error.
.SH ERRORS
.I Mknod
will fail and the file mode will be unchanged if:
.TP 20
[EPERM]
The process's effective user ID is not the super-user.
.TP 20
[EINVAL]
The path name contains a non-ASCII byte.
.TP 20
[ENOTDIR]
A component of the path prefix is not a directory.
.TP 20
[ENOENT]
A component of the path prefix does not exist.
.TP 20
[EROFS]
The named file resides on a read-only file system.
.TP 20
[EEXIST]
The named file exists.
.TP 20
[EFAULT]
.I Name
points outside the process's allocated address space.
.TP 20
[ELOOP]
Too many symbolic links were encountered in translating the path name.
.SH "SEE ALSO"
mkdir(1), mknod(1), filsys(5)
.SH ASSEMBLER
(mknod = 14.)
.br
.B sys  mknod; name; mode; addr