PHP pages with f*() file access

[Brainz]

I've got a php page which essentially parses a plain-text todo and appointment list. However, you can specify the order that the appointments are shown in, or that some appointments don't display on the main page, only in a popup window, independantly of the order in the text.
What I'm wondering is whether it would be more efficient to load the entire list into an array before sorting it, and then pass the array to the popup, or to read (and parse) the file twice: once in the main page, ignoring the "do not display" items, and then again in the popup?