int mkdirat(int dirfd, const char *pathname, mode_t mode);
描述The mkdirat() system call operates in exactly the same way as mkdir(2), except for the differences described in this manual page.
If the pathname given in pathname is relative, then it is interpreted relative to the directory referred to by the file descriptor dirfd (rather than relative to the current working directory of the calling process, as is done by mkdir(2) for a relative pathname).
If the pathname given in pathname is relative and dirfd is the special value AT_FDCWD, then pathname is interpreted relative to the current working directory of the calling process (like mkdir(2)).
If the pathname given in pathname is absolute, then dirfd is ignored.
返回值On success, mkdirat() returns 0. On error, -1 is returned and errno is set to indicate the error.
错误The same errors that occur for mkdir(2) can also occur for mkdirat(). The following additional errors can occur for mkdirat():
|EBADF||dirfd is not a valid file descriptor.|
|pathname is a relative path and dirfd is a file descriptor referring to a file other than a directory.|