The glob function, the subject of a recent post on NETTUTS.com, is the topic of this new post from Bill Karwin on the php|architect website. He focuses on the efficiency of the function over the convenience it offers.
The glob() function is convenient but the solution using the fewest lines of code isn't always the most efficient - if by efficient you mean fastest. [...] My benchmark results ranged from 12.4 seconds down to 1.2 seconds. That's a pretty wide spread, so it's worth paying attention to performance as well as coding convenience.
He shows the different methods he used to get those results, one that returned an array and filtered directories, another that didn't filter and a third using the GLOB_NOSORT argument. He also compares it with scandir and the opendir/readdir combo.