I don&#x27;t know the most recent, but it&#x27;s probably been awhile since it was usable.<p>The first UNIX I programmed on (SVR2, circa 85-86) still worked that way (no opendir&#x2F;readdir) since it had the classic V7 filesystem.  Each directory entry was just a fixed-size 16 byte chunk; 2 bytes for the inode number and 14 for the filename.<p>Of course, this meant a limitation of 64K files per filesystem -- that was still OK for us (40MB would be a large disk) but was already would have caused problems for bigger servers.  It also was the cause of the &quot;classic&quot; UNIX 14-character filename limit.<p>By that time BSD4.2&#x27;s FFS filesystem had already removed both of these limits (which I assume is when opendir() and friends arrived)  According to wikipedia that made it to the AT&amp;T world by SVR4 in the late 80s, which sounds correct.<p>As someone else mentioned some UNIXes may still let you open() a directory.  However, since we&#x27;re long past the days of there being just one &quot;UNIX filesystem&quot; it would be impossible to interpret its contents in a portable manner.