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MKDIR(2)                      System Calls Manual                     MKDIR(2)

NAME
     mkdir, mkdirat - make a directory file

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/stat.h>

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

     #include <sys/stat.h>
     #include <fcntl.h>

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

DESCRIPTION
     The directory path is created with the access permissions specified by
     mode and restricted by the umask(2) of the calling process.  On NetBSD
     all other mode bits (S_ISUID, S_ISGID, S_ISTXT) are ignored.  This is
     implementation defined; for example on Linux S_ISTXT is honored.

     mkdirat() works the same way as mkdir() except if path is relative.  In
     that case, it is looked up from a directory whose file descriptor was
     passed as fd.  Search permission is required this directory.  fd can be
     set to AT_FDCWD in order to specify the current directory.

     The directory's owner ID is set to the process's effective user ID.  The
     directory's group ID is set to that of the parent directory in which it
     is created.

RETURN VALUES
     The mkdir() and mkdirat() functions return the value 0 if successful;
     otherwise the value -1 is returned and the global variable errno is set
     to indicate the error.

ERRORS
     Both mkdir() and mkdirat() will fail and no directory will be created if:

     [EACCES]           Search permission is denied for a component of the
                        path prefix.

     [EDQUOT]           The new directory cannot be created because the user's
                        quota of disk blocks on the file system that will
                        contain the directory has been exhausted.  Or, the
                        user's quota of inodes on the file system on which the
                        directory is being created has been exhausted.

     [EEXIST]           The named file exists.

     [EFAULT]           path points outside the process's allocated address
                        space.

     [EIO]              An I/O error occurred while making the directory entry
                        or allocating the inode; or an I/O error occurred
                        while reading from or writing to the file system.

     [ELOOP]            Too many symbolic links were encountered in
                        translating the pathname.

     [ENAMETOOLONG]     A component of a pathname exceeded {NAME_MAX}
                        characters, or an entire path name exceeded {PATH_MAX}
                        characters.

     [ENOENT]           A component of the path prefix does not exist.

     [ENOSPC]           The new directory cannot be created because there is
                        no space left on the file system that will contain the
                        directory.  Or, there are no free inodes on the file
                        system on which the directory is being created.

     [ENOTDIR]          A component of the path prefix is not a directory.

     [EROFS]            The named file resides on a read-only file system.

     In addition, mkdirat() will fail if:

     [EBADF]            path does not specify an absolute path and fd is
                        neither AT_FDCWD nor a valid file descriptor open for
                        reading or searching.

     [ENOTDIR]          path is not an absolute path and fd is a file
                        descriptor associated with a non-directory file.

SEE ALSO
     chmod(2), stat(2), umask(2)

STANDARDS
     The mkdir() function conforms to IEEE Std 1003.1-1990 ("POSIX.1").
     mkdirat() conforms to IEEE Std 1003.1-2008 ("POSIX.1").

HISTORY
     The mkdir() function appeared in Version 1 AT&T UNIX.

NetBSD 10.99                   February 4, 2020                   NetBSD 10.99