— make a directory
char *path, mode_t
fd, const char
The directory path is created with the access permissions specified by mode and restricted by the umask(2) of the calling process.
The directory's owner ID is set to the process's effective user ID. The directory's group ID is set to that of the parent directory in which it is created.
function is equivalent to
except that where path specifies a relative path, the
newly created directory is created relative to the directory associated with
file descriptor fd instead of the current working
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
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.
mkdirat() will fail and no directory will be created
- A component of the path prefix is not a directory.
- A component of a pathname exceeded
NAME_MAXcharacters, or an entire pathname (including the terminating NUL) exceeded
- 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 named file resides on a read-only file system.
- The named file exists.
- The new directory cannot be created because there is no space left on the file system that will contain the directory.
- There are no free inodes on the file system on which the directory is being created.
- The new directory cannot be created because the user's quota of disk blocks on the file system that will contain the directory has been exhausted.
- The user's quota of inodes on the file system on which the directory is being created has been exhausted.
- An I/O error occurred while making the directory entry or allocating the inode.
- An I/O error occurred while reading from or writing to the file system.
- path points outside the process's allocated address space.
mkdirat() will fail if:
- The path argument specifies a relative path and the
fd argument is neither
AT_FDCWDnor a valid file descriptor.
- The path argument specifies a relative path and the fd argument is a valid file descriptor but it does not reference a directory.
- The path argument specifies a relative path but search permission is denied for the directory which the fd file descriptor references.
chmod(2), stat(2), umask(2)
mkdirat() functions conform to IEEE
Std 1003.1-2008 (“POSIX.1”).
mkdir() system call first appeared in
Version 1 AT&T UNIX. It was renamed to
makdir() in Version 2
AT&T UNIX. However, it did not exist from
Version 4 AT&T UNIX to
4.1BSD; in those releases,
mknod(2) had to be used. Since
reappeared in 4.1cBSD, it no longer requires
superuser privileges and it automatically creates the ‘.’ and
‘..’ directory entries.
mkdirat() system call has been
available since OpenBSD 5.0.