Section: Linux Programmer's Manual (2)
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mknod - create a special or ordinary file
int mknod(const char *pathname, mode_t mode, dev_t dev);
Feature Test Macro Requirements for glibc (see
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
The system call
creates a file system node (file, device special file or
named pipe) named
with attributes specified by
argument specifies both the permissions to use and the type of node
to be created.
It should be a combination (using bitwise OR) of one of the file types
listed below and the permissions for the new node.
The permissions are modified by the process's
in the usual way: the permissions of the created node are
(mode & ~umask).
The file type must be one of
to specify a regular file (which will be created empty), character
special file, block special file, FIFO (named pipe), or Unix domain socket,
(Zero file type is equivalent to type
If the file type is
specifies the major and minor numbers of the newly created device
may be useful to build the value for
otherwise it is ignored.
already exists, or is a symbolic link, this call fails with an
The newly created node will be owned by the effective user ID of the
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
new node will inherit the group ownership from its parent directory;
otherwise it will be owned by the effective group ID of the process.
returns zero on success, or -1 if an error occurred (in which case,
is set appropriately).
The parent directory does not allow write permission to the process,
or one of the directories in the path prefix of
did not allow search permission.
This includes the case where
is a symbolic link, dangling or not.
pathname points outside your accessible address space.
requested creation of something other than a regular file, device
special file, FIFO or socket.
Too many symbolic links were encountered in resolving
pathname was too long.
A directory component in
does not exist or is a dangling symbolic link.
Insufficient kernel memory was available.
The device containing
has no room for the new node.
A component used as a directory in
is not, in fact, a directory.
requested creation of something other than a regular file,
FIFO (named pipe), or Unix domain socket, and the caller
is not privileged (Linux: does not have the
also returned if the file system containing
does not support the type of node requested.
refers to a file on a read-only file system.
SVr4, 4.4BSD, POSIX.1-2001 (but see below).
POSIX.1-2001 says: "The only portable use of
is to create a FIFO-special file.
is not 0, the behavior of
However, nowadays one should never use
for this purpose; one should use
a function especially defined for this purpose.
Under Linux, this call cannot be used to create directories.
One should make directories with
There are many infelicities in the protocol underlying NFS.
Some of these affect
This page is part of release 3.27 of the Linux
A description of the project,
and information about reporting bugs,
can be found at
- RETURN VALUE
- CONFORMING TO
- SEE ALSO
This document was created by
using the manual pages.