MKDIR(2) Linux Programmer's Manual MKDIR(2)NAME
mkdir, mkdirat - create a directory
int mkdir(const char *pathname, mode_t mode);
#include <fcntl.h> /* Definition of AT_* constants */
int mkdirat(int dirfd, const char *pathname, mode_t mode);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
Since glibc 2.10:
_XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
DESCRIPTIONmkdir() attempts to create a directory named pathname.
The argument mode specifies the permissions to use. It is modified by
the process's umask in the usual way: the permissions of the created
directory are (mode & ~umask & 0777). Other mode bits of the created
directory depend on the operating system. For Linux, see 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.
The mkdirat() system call operates in exactly the same way as mkdir(),
except for the differences described here.
If the pathname given in pathname is relative, then it is interpreted
relative to the directory referred to by the file descriptor dirfd
(rather than relative to the current working directory of the calling
process, as is done by mkdir() for a relative pathname).
If pathname is relative and dirfd is the special value AT_FDCWD, then
pathname is interpreted relative to the current working directory of
the calling process (like mkdir()).
If pathname is absolute, then dirfd is ignored.
See openat(2) for an explanation of the need for mkdirat().
RETURN VALUEmkdir() and mkdirat() return zero on success, or -1 if an error
occurred (in which case, errno is set appropriately).
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).)
EDQUOT The user's quota of disk blocks or inodes on the filesystem has
EEXIST pathname already exists (not necessarily as a directory). This
includes the case where pathname is a symbolic link, dangling or
EFAULT pathname points outside your accessible address space.
ELOOP Too many symbolic links were encountered in resolving pathname.
EMLINK The number of links to the parent directory would exceed
pathname was too long.
ENOENT A directory component in pathname does not exist or is a dan‐
gling symbolic link.
ENOMEM Insufficient kernel memory was available.
ENOSPC The device containing pathname has no room for the new direc‐
ENOSPC The new directory cannot be created because the user's disk
quota is exhausted.
A component used as a directory in pathname is not, in fact, a
EPERM The filesystem containing pathname does not support the creation
EROFS pathname refers to a file on a read-only filesystem.
The following additional errors can occur for mkdirat():
EBADF dirfd is not a valid file descriptor.
pathname is relative and dirfd is a file descriptor referring to
a file other than a directory.
VERSIONSmkdirat() was added to Linux in kernel 2.6.16; library support was
added to glibc in version 2.4.
CONFORMING TOmkdir(): SVr4, BSD, POSIX.1-2001, POSIX.1-2008.
Under Linux apart from the permission bits, only the S_ISVTX mode bit
is honored. That is, under Linux the created directory actually gets
mode (mode & ~umask & 01777). See also stat(2).
There are many infelicities in the protocol underlying NFS. Some of
these affect mkdir().
SEE ALSOmkdir(1), chmod(2), chown(2), mknod(2), mount(2), rmdir(2), stat(2),
umask(2), unlink(2), path_resolution(7)COLOPHON
This page is part of release 3.65 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2014-02-21 MKDIR(2)