4.2BSD/usr/man/man2/mknod.2

.TH MKNOD 2 "2 July 1983"
.UC 4
.SH NAME
mknod \- make a special file
.SH SYNOPSIS
.nf
.ft B
mknod(path, mode, dev)
char *path;
int mode, dev;
.fi
.ft R
.SH DESCRIPTION
.I Mknod
creates a new file
whose name is
.I path.
The mode of the new file
(including 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
.I dev 
and is used to specify which device the special file
refers to.
.PP
If mode indicates a block or character special file,
.I dev
is a configuration dependent specification of a character or block
I/O device.  If
.I mode
does not indicate a block special or character special device,
.I dev
is ignored.
.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 \fIerrno\fP
is set to indicate the error.
.SH ERRORS
.I Mknod
will fail and the file mode will be unchanged if:
.TP 15
[EPERM]
The process's effective user ID is not super-user.
.TP 15
[EPERM]
The pathname contains a character with the high-order bit set.
.TP 15
[ENOTDIR]
A component of the path prefix is not a directory.
.TP 15
[ENOENT]
A component of the path prefix does not exist.
.TP 15
[EROFS]
The named file resides on a read-only file system.
.TP 15
[EEXIST]
The named file exists.
.TP 15
[EFAULT]
.I Path
points outside the process's allocated address space.
.TP 15
[ELOOP]
Too many symbolic links were encountered in translating the pathname.
.SH "SEE ALSO"
chmod(2), stat(2), umask(2)