/^[\da-f][\da-f]:
  [\da-f][\da-f]:
  [\da-f][\da-f]:
  [\da-f][\da-f]:
  [\da-f][\da-f]:
  [\da-f][\da-f]$/ix

[download]

Or with less typing: 

/^
  (?:
     [\da-f]{2}:
   ){5}
  [\da-f]{2}
$/ix;

[download]

I used the /x modifier to allow for freeform whitespace within the RE. I used the /i modifier so that hex digits can be represented in either lower or upper case. And in the second example, quantifiers were used to factor out the unnecessary repetition.

Update: Fixed quantifier on last term.


Dave

In reply to Re: Long regexp un multiple lines by davido
in thread Long regexp un multiple lines by Lorand

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