table of contents
|MKNOD(2)||System Calls Manual||MKNOD(2)|
— make a special file node
Standard C Library (libc, -lc)
char *path, mode_t
fd, const char
*path, mode_t mode,
The file system node path is created with the file type and access permissions specified in mode. The access permissions are modified by the process's umask value.
If mode indicates a block or character special file, dev is a configuration dependent specification denoting a particular device on the system. Otherwise, dev is ignored.
system call requires super-user privileges.
system call is equivalent to
mknod() except in the
case where path specifies a relative path. In this
case the newly created device node is created relative to the directory
associated with the file descriptor fd instead of the
current working directory. If
mknodat() is passed
the special value
AT_FDCWD in the
fd parameter, the current working directory is used
and the behavior is identical to a call to
mknod() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno is set to indicate the
mknod() system call will fail and the
file will be not created if:
- A component of the path prefix is not a directory.
- A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
- A component of the path prefix does not exist.
- Search permission is denied for a component of the path prefix.
- Too many symbolic links were encountered in translating the pathname.
- The process's effective user ID is not super-user.
- An I/O error occurred while making the directory entry or allocating the inode.
- Corrupted data was detected while reading from the file system.
- 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.
- There are no free inodes on the file system on which the node is being created.
- 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.
- The user's quota of inodes on the file system on which the node is being created has been exhausted.
- The named file resides on a read-only file system.
- The named file exists.
- The path argument points outside the process's allocated address space.
- Creating anything else than a block or character special file (or a whiteout) is not supported.
In addition to the errors returned by the
mknodat() system call follows The Open
Group Extended API Set 2 specification.
mknod() function appeared in
Version 4 AT&T UNIX. The
mknodat() system call appeared in
|March 30, 2020||Debian|