.\" This manpage is Copyright (C) 1992 Drew Eckhardt;
.\" and Copyright (C) 1993 Michael Haardt
-.\" and Copyright (C) 1993,1994 Ian Jackson.
+.\" and Copyright (C) 1993,1994 Ian Jackson
+.\" and Copyright (C) 2006, 2014, Michael Kerrisk
.\"
.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
.\" You may distribute it under the terms of the GNU General
.\" Modified 2003-04-23 by Michael Kerrisk
.\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com>
.\"
-.TH MKNOD 2 2013-01-27 "Linux" "Linux Programmer's Manual"
+.TH MKNOD 2 2014-02-21 "Linux" "Linux Programmer's Manual"
.SH NAME
-mknod \- create a special or ordinary file
+mknod, mknodat \- create a special or ordinary file
.SH SYNOPSIS
.nf
.B #include <sys/types.h>
.B #include <unistd.h>
.sp
.BI "int mknod(const char *" pathname ", mode_t " mode ", dev_t " dev );
+.sp
+.BR "#include <fcntl.h> " "/* Definition of AT_* constants */"
+.B #include <sys/stat.h>
+.sp
+.BI "int mknodat(int " dirfd ", const char *" pathname ", mode_t " mode \
+", dev_t " dev );
.fi
.sp
.in -4n
.SH DESCRIPTION
The system call
.BR mknod ()
-creates a file system node (file, device special file or
+creates a filesystem node (file, device special file, or
named pipe) named
.IR pathname ,
with attributes specified by
.BR S_IFREG ,
.BR S_IFCHR ,
.BR S_IFBLK ,
-.B S_IFIFO
+.BR S_IFIFO ,
or
.B S_IFSOCK
.\" (S_IFSOCK since Linux 1.2.4)
If the file type is
.B S_IFCHR
or
-.B S_IFBLK
+.BR S_IFBLK ,
then
.I dev
specifies the major and minor numbers of the newly created device
The newly created node will be owned by the effective user ID of the
process.
If the directory containing the node has the set-group-ID
-bit set, or if the file system is mounted with BSD group semantics, the
+bit set, or if the filesystem is mounted with BSD group semantics, the
new node will inherit the group ownership from its parent directory;
otherwise it will be owned by the effective group ID of the process.
+.\"
+.\"
+.SS mknodat()
+The
+.BR mknodat ()
+system call operates in exactly the same way as
+.BR mknod (2),
+except for the differences described here.
+
+If the pathname given in
+.I pathname
+is relative, then it is interpreted relative to the directory
+referred to by the file descriptor
+.I dirfd
+(rather than relative to the current working directory of
+the calling process, as is done by
+.BR mknod (2)
+for a relative pathname).
+
+If
+.I pathname
+is relative and
+.I dirfd
+is the special value
+.BR AT_FDCWD ,
+then
+.I pathname
+is interpreted relative to the current working
+directory of the calling process (like
+.BR mknod (2)).
+
+If
+.I pathname
+is absolute, then
+.I dirfd
+is ignored.
+.PP
+See
+.BR openat (2)
+for an explanation of the need for
+.BR mknodat ().
.SH RETURN VALUE
.BR mknod ()
-returns zero on success, or \-1 if an error occurred (in which case,
+and
+.BR mknodat ()
+return zero on success, or \-1 if an error occurred (in which case,
.I errno
is set appropriately).
.SH ERRORS
.BR path_resolution (7).)
.TP
.B EDQUOT
-The user's quota of disk blocks or inodes on the file system has been
+The user's quota of disk blocks or inodes on the filesystem has been
exhausted.
.TP
.B EEXIST
.\" For UNIX domain sockets and regular files, EPERM is returned only in
.\" Linux 2.2 and earlier; in Linux 2.4 and later, unprivileged can
.\" use mknod() to make these files.
-also returned if the file system containing
+also returned if the filesystem containing
.I pathname
does not support the type of node requested.
.TP
.B EROFS
.I pathname
-refers to a file on a read-only file system.
+refers to a file on a read-only filesystem.
+.PP
+The following additional errors can occur for
+.BR mknodat ():
+.TP
+.B EBADF
+.I dirfd
+is not a valid file descriptor.
+.TP
+.B ENOTDIR
+.I pathname
+is relative and
+.I dirfd
+is a file descriptor referring to a file other than a directory.
+.SH VERSIONS
+.BR mknodat ()
+was added to Linux in kernel 2.6.16;
+library support was added to glibc in version 2.4.
.SH CONFORMING TO
-SVr4, 4.4BSD, POSIX.1-2001 (but see below).
+.BR mknod ():
+SVr4, 4.4BSD, POSIX.1-2001 (but see below), POSIX.1-2008.
.\" The Linux version differs from the SVr4 version in that it
.\" does not require root permission to create pipes, also in that no
.\" EMULTIHOP, ENOLINK, or EINTR error is documented.
+
+.BR mknodat ():
+POSIX.1-2008.
.SH NOTES
POSIX.1-2001 says: "The only portable use of
.BR mknod ()
.BR mkfifo (3),
a function especially defined for this purpose.
-Under Linux, this call cannot be used to create directories.
+Under Linux,
+.BR mknod ()
+cannot be used to create directories.
One should make directories with
.BR mkdir (2).
.\" and one should make UNIX domain sockets with socket(2) and bind(2).
There are many infelicities in the protocol underlying NFS.
Some of these affect
-.BR mknod ().
+.BR mknod ()
+and
+.BR mknodat (2).
.SH SEE ALSO
.BR chmod (2),
.BR chown (2),
.BR fcntl (2),
.BR mkdir (2),
-.BR mknodat (2),
.BR mount (2),
.BR socket (2),
.BR stat (2),
.BR makedev (3),
.BR mkfifo (3),
.BR path_resolution (7)
+.SH COLOPHON
+This page is part of release 3.79 of the Linux
+.I man-pages
+project.
+A description of the project,
+information about reporting bugs,
+and the latest version of this page,
+can be found at
+\%http://www.kernel.org/doc/man\-pages/.
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