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

       mkdir, mkdirat - create a directory

       #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);

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

           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:

       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.

       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().

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

       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

       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.

              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.

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

              (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.

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

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

       mkdirat(): POSIX.1-2008.

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

       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.

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

       This page is part of release 5.13 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

Linux                              2021-08-27                           MKDIR(2)