NAME¶

mkdir, mkdirat - create a directory

LIBRARY¶

Standard C library (libc, -lc)

SYNOPSIS¶

#include <sys/stat.h>

int mkdir(const char *pathname, mode_t mode);

#include <fcntl.h>           /* Definition of AT_* constants */
#include <sys/stat.h>

int mkdirat(int dirfd, const char *pathname, mode_t mode);

mkdirat():

    Since glibc 2.10:


        _POSIX_C_SOURCE >= 200809L


    Before glibc 2.10:


        _ATFILE_SOURCE

DESCRIPTION¶

mkdir() attempts to create a directory named pathname.

The argument mode specifies the mode for the new directory (see inode(7)). It is modified by the process's umask in the usual way: in the absence of a default ACL, the mode of the created directory is (mode & ~umask & 0777). Whether other mode bits are honored for the created directory depends on the operating system. For Linux, see NOTES below.

The newly created directory will be owned by the effective user ID of the process. If the directory containing the file has the set-group-ID bit set, or if the filesystem is mounted with BSD group semantics (mount -o bsdgroups or, synonymously mount -o grpid), the new directory will inherit the group ownership from its parent; otherwise it will be owned by the effective group ID of the process.

If the parent directory has the set-group-ID bit set, then so will the newly created directory.

RETURN VALUE¶

mkdir() and mkdirat() return zero on success. On error, -1 is returned and errno is set to indicate the error.

ERRORS¶

EACCES

The parent directory does not allow write permission to the process, or one of the directories in pathname did not allow search permission. (See also path_resolution(7).)

EBADF

(mkdirat()) pathname is relative but dirfd is neither AT_FDCWD nor a valid file descriptor.

EDQUOT

The user's quota of disk blocks or inodes on the filesystem has been exhausted.

EEXIST

pathname already exists (not necessarily as a directory). This includes the case where pathname is a symbolic link, dangling or not.

EFAULT

pathname points outside your accessible address space.

EINVAL

The final component ("basename") of the new directory's pathname is invalid (e.g., it contains characters not permitted by the underlying filesystem).

ELOOP

Too many symbolic links were encountered in resolving pathname.

EMLINK

The number of links to the parent directory would exceed LINK_MAX.

ENAMETOOLONG

pathname was too long.

ENOENT

A directory component in pathname does not exist or is a dangling symbolic link.

ENOMEM

Insufficient kernel memory was available.

ENOSPC

The device containing pathname has no room for the new directory.

ENOSPC

The new directory cannot be created because the user's disk quota is exhausted.

ENOTDIR

A component used as a directory in pathname is not, in fact, a directory.

ENOTDIR

(mkdirat()) pathname is relative and dirfd is a file descriptor referring to a file other than a directory.

EPERM

The filesystem containing pathname does not support the creation of directories.

EROFS

pathname refers to a file on a read-only filesystem.

VERSIONS¶

mkdirat() was added in Linux 2.6.16; library support was added in glibc 2.4.

STANDARDS¶

mkdir(): SVr4, BSD, POSIX.1-2001, POSIX.1-2008.

mkdirat(): POSIX.1-2008.

NOTES¶

Under Linux, apart from the permission bits, the S_ISVTX mode bit is also honored.

There are many infelicities in the protocol underlying NFS. Some of these affect mkdir().

SEE ALSO¶

mkdir(1), chmod(2), chown(2), mknod(2), mount(2), rmdir(2), stat(2), umask(2), unlink(2), acl(5), path_resolution(7)