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MKNOD(2)		  FreeBSD System Calls Manual		      MKNOD(2)

NAME
     mknod, mknodat -- make a special file node

SYNOPSIS
     #include <sys/stat.h>

     int
     mknod(const char *path, mode_t mode, dev_t	dev);

     #include <sys/stat.h>
     #include <fcntl.h>

     int
     mknodat(int fd, const char	*path, mode_t mode, dev_t dev);

DESCRIPTION
     The mknod() function creates path with a file type	and mode of mode, as
     modified by umask(2).  Only FIFO and device special files are supported
     by	this implementation.

     If	mode is	the bitwise OR of S_IFIFO and zero or more file	permissions,
     and dev is	zero, then a FIFO is created.  If mode is the bitwise OR of
     S_IFCHR or	S_IFBLK	and zero or more file permissions, then	a character or
     block device special (respectively) is created with major and minor de-
     vice numbers extracted from dev.

     The mknodat() function is equivalent to mknod() except that where path
     specifies a relative path,	the newly created device special file is cre-
     ated relative to the directory associated with file descriptor fd instead
     of	the current working directory.

     If	mknodat() is passed the	special	value AT_FDCWD (defined	in <fcntl.h>)
     in	the fd parameter, the current working directory	is used	and the	behav-
     ior is identical to a call	to mknod().

     Creating a	device special file with mknod() or mknodat() requires supe-
     ruser privileges.

RETURN VALUES
     Upon successful completion, the value 0 is	returned; otherwise the
     value -1 is returned and the global variable errno	is set to indicate the
     error.

ERRORS
     mknod() and mknodat() will	fail and the file will be not created if:

     [EINVAL]		mode is	an invalid file	type or	dev is an invalid
			value for that file type.

     [ENOTDIR]		A component of the path	prefix is not a	directory.

     [ENAMETOOLONG]	A component of a pathname exceeded NAME_MAX charac-
			ters, or an entire pathname (including the terminating
			NUL) exceeded PATH_MAX bytes.

     [ENOENT]		A component of the path	prefix does not	exist.

     [EACCES]		Search permission is denied for	a component of the
			path prefix.

     [ELOOP]		Too many symbolic links	were encountered in translat-
			ing the	pathname.

     [EPERM]		mode is	a device special and the process's effective
			user ID	is not superuser.

     [EIO]		An I/O error occurred while making the directory entry
			or allocating the inode.

     [ENOSPC]		The directory in which the entry for the new node is
			being placed cannot be extended	because	there is no
			space left on the file system containing the direc-
			tory.

     [ENOSPC]		There are no free inodes on the	file system on which
			the node is being created.

     [EDQUOT]		The directory in which the entry for the new node is
			being placed cannot be extended	because	the user's
			quota of disk blocks on	the file system	containing the
			directory has been exhausted.

     [EDQUOT]		The user's quota of inodes on the file system on which
			the node is being created has been exhausted.

     [EROFS]		The named file resides on a read-only file system.

     [EEXIST]		The named file exists.

     [EFAULT]		path points outside the	process's allocated address
			space.

     [EINVAL]		The process is running within an alternate root	direc-
			tory, as created by chroot(2).

     Additionally, mknodat() will fail if:

     [EBADF]		The path argument specifies a relative path and	the fd
			argument is neither AT_FDCWD nor a valid file descrip-
			tor.

     [ENOTDIR]		The path argument specifies a relative path and	the fd
			argument is a valid file descriptor but	it does	not
			reference a directory.

     [EACCES]		The path argument specifies a relative path but	search
			permission is denied for the directory which the fd
			file descriptor	references.

SEE ALSO
     chmod(2), chroot(2), mkfifo(2), stat(2), umask(2)

STANDARDS
     The mknod() and mknodat() functions conform to IEEE Std 1003.1-2008
     ("POSIX.1").

HISTORY
     The mknod() system	call first appeared in Version 4 AT&T UNIX, and
     mknodat() has been	available since	OpenBSD	5.0.

FreeBSD	13.0		      September	10, 2015		  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | STANDARDS | HISTORY

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