NAME
mknod
, mknodat
— make a special file
node
SYNOPSIS
#include
<sys/stat.h>
#include <fcntl.h>
int
mknod
(const
char *path, mode_t
mode, dev_t
dev);
int
mknodat
(int
fd, const char
*path, mode_t mode,
dev_t dev);
DESCRIPTION
The device special file path is created with the major and minor device numbers extracted from mode. The access permissions of path are descendant from the umask(2) of the parent process.
If mode indicates a block or character special file, dev is a configuration dependent specification of a character or block I/O device and the superblock of the device. If mode does not indicate a block special or character special device, dev is ignored.
mknod
()
requires superuser privileges.
The
mknodat
()
function is equivalent to mknod
() except that where
path specifies a relative path, the newly created
device special file is created 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 behavior is identical to a call to
mknod
().
RETURN VALUES
Upon successful completion a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.
ERRORS
mknod
() and
mknodat
() will fail and the file will be not created
if:
- [
ENOTDIR
] - A component of the path prefix is not a directory.
- [
ENAMETOOLONG
] - A component of a pathname exceeded
{NAME_MAX}
characters, or an entire path name exceeded{PATH_MAX}
characters. - [
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 translating the pathname.
- [
EPERM
] - 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 directory.
- [
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 directory, as created by chroot(2).
mknodat
() will fail if:
- [
EBADF
] - The path argument does not specify an absolute path
and the fd argument is neither
AT_FDCWD
nor a valid file descriptor open for reading.
SEE ALSO
HISTORY
A mknod
() function call appeared in
Version 6 AT&T UNIX. The
mknodat
() function appeared in
OpenBSD 5.0.