in reply to One regex construct to handle multiple string types

One (of many) solutions would be to anchor your regex to the end of the string: 
/(.{2})$/

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Re^2: One regex construct to handle multiple string types
by JadeNB (Chaplain) on Nov 30, 2008 at 18:34 UTC
    I think the poster didn't want so much the final two characters (which could be got by substr($_, -2) anyway) as non-space characters after a period. Of course, your regex could easily be adapted to /\.(\S+)$/; but I think the sexeger /^(\S+)\./ should be quicker on some inputs (in the sense that it doesn't have to back-track on pathological strings like '............... .a').

    UPDATE: My sexeger can behave badly on strings with multiple periods in them. Two natural changes are to make the \S+ match non-greedy, or to change \S to [^.]. These have different matching behaviour, especially on strings with characters that are neither spaces nor 'word' characters, and on strings with multiple periods; but one of them might do what the poster wants.
    Also, I changed the sample string to one that actually matches.

    UPDATE 2: Oops, on re-reading, the poster explicitly wants to allow strings without any periods at all. Never mind.

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