Re: Extending regexes

[stephane@xxxxxxxxxxxx]

FWIW, ast's extended and augmented regexps as supported by ksh93's [[ =~ 
]] operator or more generally in globs after ~(E) (extended) ~(A) 
(augmented) do have AND and NOT operator.

That's \& and \! in ERE and & and ! in ARE.

ere() ksh -c '[[ $1 =~ $2 ]]' ksh "$@"
are() ksh -c '[[ $1 =~ (?A)$2 ]]' ksh "$@"

And then you can do

ere x '^([[:lower:]]\&.)$'
ere y '^x\!$'

are x '^([[:lower:]]&.)$'
are y '^x!$'

Also note that AND(A,B) can be done with NOT(OR(NOT(A), NOT(B))) so even 
ksh88 or bash can do AND in their globs (with extglob in bash) with 
!(!(A)|!(B))

--
Stephane