MKDIR(2) System Calls MKDIR(2)


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(5) for descriptions of the following attributes:


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

SEE ALSO


chmod(2), mknod(2), umask(2), mkdirp(3GEN), stat.h(3HEAD), attributes(5),
standards(5)


September 24, 2016 MKDIR(2)