mkdir(2) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

MKDIR(2)                Linux Programmer's Manual               MKDIR(2)

NAME         top

       mkdir, mkdirat - create a directory

SYNOPSIS         top

       #include <sys/stat.h>
       #include <sys/types.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);

   Feature Test Macro Requirements for glibc (see
   feature_test_macros(7)):

       mkdirat():
           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:
               _ATFILE_SOURCE

DESCRIPTION         top

       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.

   mkdirat()
       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 VALUE         top

       mkdir() and mkdirat() return zero on success, or -1 if an error
       occurred (in which case, errno is set appropriately).

ERRORS         top

       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 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.

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

       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.

       ENOTDIR
              pathname is relative and dirfd is a file descriptor
              referring to a file other than a directory.

VERSIONS         top

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

CONFORMING TO         top

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

       mkdirat(): POSIX.1-2008.

NOTES         top

       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().

   Glibc notes
       On older kernels where mkdirat() is unavailable, the glibc
       wrapper function falls back to the use of mkdir().  When pathname
       is a relative pathname, glibc constructs a pathname based on the
       symbolic link in /proc/self/fd that corresponds to the dirfd
       argument.

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 5.10 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

Linux                          2020-06-09                       MKDIR(2)

Pages that refer to this page: mkdir(1)chmod(2)chown(2)fanotify_mark(2)fcntl(2)mknod(2)open(2)rmdir(2)syscalls(2)umask(2)mkdtemp(3)proc(5)cpuset(7)inotify(7)signal-safety(7)mount(8)