I never got into Perl, but I'd imagine that any basic PHP functions would also exist in Perl--but I don't know what they'd be called.
If they don't have a specific round() function, I would guess that it's something that could be written using existing functions.
Maybe there are a few Perl users here that will read the thread--but if not, you could always give Google a try, or maybe a programming forum on a site like Digitalpoint.com or sitepoint.com.
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