Add some more testcases to this: 

m[^(?=.*[a-zA-Z])[\w]+$] and print "$_ : ok" 
    for qw[ 123 123_ 123_a a_ a_123 abc _ a123];
123_a : ok
a_ : ok
a_123 : ok
abc : ok
a123 : ok

[download]

Tweaked: The \d was redundant.

Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail
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In reply to Re: A single regex by BrowserUk
in thread A single regex by kiat

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