Oops. Didn't notice the ; at the end of the pattern you want to avoid.

What Tanktalus said: /&(?!amp;)/ .

/&(?!amp\b)/

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The above will match &, &foo, &ersand, but not & followed by a \W character or by the end of the string. If you don't want to match &, irrespective of what follows it, then use 
/&(?!amp)/

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 See ?! in perlre.

the lowliest monk

In reply to Re: using regex to not match a string by tlm
in thread using regex to not match a string by Anonymous Monk

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