How to validate hostname in perl?

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Published on 2010-06-10T07:45:38Z Indexed on 2010/06/10 7:52 UTC
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regex

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perl

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hostname

Hi,

I need to come up with a regular expression to validate hostname against RFC-1123 and RFC-952.

Right now I'm using this:

^(?=.{1,255}$)[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-){0,61}[0-9A-Za-z])?)*\.?$/

but this does not do the trick since it does not catch a. as invalid hostname.

How do I enhance the reg expression to comply with those RFCs?

Thanks

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