NAME

mkdir, mkdirat - make a directory

SYNOPSIS

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

int mkdirat(int fd, const char *path, mode_t mode);

DESCRIPTION

The mkdir() and mkdirat() functions create a new directory named by the path name pointed to by path. The mode of the new directory is initialized from mode (see chmod(2) for values of mode). The protection part of the mode argument is modified by the process's file creation 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 names a symbolic link, mkdir() and mkdirat() fail and set errno to EEXIST.

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

The mkdirat() function behaves similarly to mkdir(); however, if path is a relative path, then the directory represented by fd is used as the starting point for resolving path. To use the processes current working directory, fd may be set to the value AT_FDCWD.

Upon successful completion, mkdir() and mkdirat() mark 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.

RETURN VALUES

Upon successful completion, 0 is returned. Otherwise, −1 is returned, no directory is created, and errno is set to indicate the error.

ERRORS

The mkdir() and mkdirat() functions will fail if:

EACCES

Either a component of the path prefix denies search permission or write permission is denied on the parent directory of the directory to be created.

EDQUOT

The directory where the new file entry is being placed cannot be extended because the user's quota of disk blocks on that file system has been exhausted; the new directory cannot be created because the user's quota of disk blocks on that file system has been exhausted; or the user's quota of inodes on the file system where the file is being created has been exhausted.

EEXIST

The named file already exists.

EFAULT

The path argument points to an illegal address.

EINVAL

An attempt was made to create an extended attribute that is a directory.

EIO

An I/O error has occurred while accessing the file system.

EILSEQ

The path argument includes non-UTF8 characters and the file system accepts only file names where all characters are part of the UTF-8 character codeset.

ELOOP

Too many symbolic links were encountered in translating path, or a loop exists in symbolic links encountered during resolution of path

EMLINK

The maximum number of links to the parent directory would be exceeded.

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

The path argument 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. For linkat(), if path is a relative path and fd refers to a valid file descriptor which is not a directory.

EROFS

The path prefix resides on a read-only file system.

The mkdirat() function will fail if:

EBADF

The path path is a relative path and fd is not a valid open file descriptor or the value AT_FDCWD.

The mkdir() function may fail if:

ENAMETOOLONG

As a result of encountering a symbolic link in resolution of the path argument, the length of the substituted pathname string exceeded {PATH_MAX}.

EXAMPLES

Example 1 Create a directory.

The following example demonstrates how to create a directory named /home/cnd/mod1, with read, write, and search permissions for owner and group, and with read and search permissions for others.

#include <sys/types.h>
#include <sys/stat.h>
int status;
...
status = mkdir("/home/cnd/mod1",


     S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Standard
MT-Level	Async-Signal-Safe