MKDIR

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 uid 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 gid 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

EPERM: The filesystem containing pathname does not support the creation of directories.
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.
EACCES: The parent directory does not allow write permission to the process, or one of the directories in pathname did not allow search (execute) permission.
ENAMETOOLONG: pathname was too long.
ENOENT: A directory component in pathname does not exist or is a dangling symbolic link.
ENOTDIR: A component used as a directory in pathname is not, in fact, a directory.
ENOMEM: Insufficient kernel memory was available.
EROFS: pathname refers to a file on a read-only filesystem.
ELOOP: Too many symbolic links were encountered in resolving pathname.
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.

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.