I'm not sure what you mean with "precision" (why isn't "12.3" valid?), but judging by your examples, and assuming your "number" really is a string, I come up with this: 

$float =~ /\A(?:\d|\d?\.\d{1,3})\z/;

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print "Just another Perl ${\(trickster and hacker)},"
The Sidhekin proves Sidhe did it!

In reply to Re: Regex for max length float by Sidhekin
in thread Regex for max length float by agianni

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