MKDIR(2)

NAME
mkdir - create a directory

SYNOPSIS
#include <sys/stat.h>
#include <sys/types.h>

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

DESCRIPTION
mkdir attempts to create a directory named pathname.

The parameter 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, 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 returns zero on success, or -1 if an error occurred (in which case, errno is set appropriately).

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(2).)

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.

ELOOP
    Too many symbolic links were encountered in resolving pathname.

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.

CONFORMING TO
SVr4, POSIX, BSD, SYSV, X/OPEN. SVr4 documents additional EIO, EMULTIHOP and ENOLINK error conditions; POSIX.1 omits ELOOP.

NOTES
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 ALSO
mkdir(1), chmod(2), mknod(2), mount(2), path_resolution(2), rmdir(2), stat(2), umask(2), unlink(2)