Regular expression for searchterms not preceded or followed by [a-z] and [A-Z]

Question

Can someone supply me with the regexp for searching for a searchterm that is not preceded or followed by [a-z] and [A-Z], other characters are ok. -> i.e. when searching for 'key' i don't want keyboard in my searchresults but key. is okay.

Thanks!

Answer 1

If using Perl what you need is \b aka "word boundary" ...

m/\bkey\b/

Answer 2

\bkey\b should do what you want.

\b is a word boundary

Answer 3

Does \b work?

Will key! or key. be found? And what about $key$?

Answer 4

Since you don't specify what regex engine you're using, I'll assume a baseline, in which case "[^A-Za-z]key[^A-Za-z]" would be sufficient.

If you also want to catch the string at the start and end of the line, you'll also have to use "^key[^A-Aa-z]" and "[^A-Aa-z]key$".

Answer 5

Or the more concise [^\w]key[^\w]

Answer 6

As question is tagged with "mysql" I assume you are using mysql regexps. Then '[[:<:]]key[[:>:]]' is what you want. See the documentation at dev.mysql.com for details.

Answer 7

No need for the "OR"s like this:

(^|[^A-Za-z])key([^A-Za-z]|$)