grep works with regular expressions (BRE) by default. Did you mean extended regular expressions (ERE) that support alternation (|) and enabling with the "-E" switch?

That will not fly, since "may" allows too much liberty. A word like "goods" would match too. And what about punctuation? What constitutes a word?

\y is a GNU extension and will not work across awks. An alternative would be to use \< and \> instead:

Code:

gawk '/\<(good|excellent|three)\>/{ print "match", $0 }'

But this isn't universal either

A universal awk approach would be something like this I guess:

Code:

awk -F'[[:space:][:punct:]]*' '{for(i=1;i<=NF;i++)if($i~/^(good|great|excellent)$/){print; next}}'

A special case would perhaps need to be made for the underscore character...