mkdir(2)

mkdir -- make a directory

Synopsis

   #include <sys/types.h>
   #include <sys/stat.h>
   
   int mkdir(const char path, mode_t mode);

Description

mkdir creates a new directory named by the pathname pointed to by path. The mode of the new directory is initialized from mode (see chmod(2) for the values of mode).

The protection part of the mode argument is modified by the process's file create mask. (See umask(2)).

The directory's owner ID is set to the process's effective user ID. The directory's group ID is set to the process's effective group ID, or if the S_ISGID bit is set in the parent directory, then the group ID of the directory is inherited from the parent. The S_ISGID bit of the new directory is inherited from the parent directory.

If path is a symbolic link, it is not followed.

The newly created directory is empty with the exception of entries for itself (.) and its parent directory (..).

Return values

On success, mkdir returns 0 and marks for update the st_atime, st_ctime and st_mtime fields of the directory. Also, the st_ctime and st_mtime fields of the directory that contains the new entry are marked for update.

On failure, mkdir returns -1 and sets errno to identify the error.

In the following conditions, mkdir fails and sets errno to:

EACCES: Search permission is denied on a component of the path prefix.
EACCES: Write permission is denied on the parent directory in which the directory is to be created.
EEXIST: The named file already exists.
EFAULT: path points outside the allocated address space of the process.
EIO: An I/O error has occurred while accessing the file system.
ELOOP: Too many symbolic links were encountered in translating path.
EMLINK: The maximum number of links to the parent directory would be exceeded.
EMULTIHOP: Components of path require hopping to multiple remote machines and the file system type does not allow it.
ENAMETOOLONG: The length of the path argument exceeds {PATH_MAX}, or the length of a path component exceeds {NAME_MAX} while _POSIX_NO_TRUNC is in effect.
ENOENT: A component of the path prefix does not exist or is a null pathname.
ENOLINK: path points to a remote machine and the link to that machine is no longer active.
ENOSPC: No free space is available on the device containing the directory.
ENOTDIR: A component of the path prefix is not a directory.
EROFS: The path prefix resides on a read-only file system.

References

chmod(2), directory(3C), mkdirp(3G), mknod(2), rmdir(2), stat(5), umask(2)