1*11be35a1SLionel Sambuc# subtleties of matching 2*11be35a1SLionel Sambucabc & xabcy abc 3*11be35a1SLionel Sambuca\(b\)?c\1d b acd 4*11be35a1SLionel SambucaBc i Abc Abc 5*11be35a1SLionel Sambuca[Bc]*d i abBCcd abBCcd 6*11be35a1SLionel Sambuc0[[:upper:]]1 &i 0a1 0a1 7*11be35a1SLionel Sambuc0[[:lower:]]1 &i 0A1 0A1 8*11be35a1SLionel Sambuca[^b]c &i abc 9*11be35a1SLionel Sambuca[^b]c &i aBc 10*11be35a1SLionel Sambuca[^b]c &i adc adc 11*11be35a1SLionel Sambuc[a]b[c] - abc abc 12*11be35a1SLionel Sambuc[a]b[a] - aba aba 13*11be35a1SLionel Sambuc[abc]b[abc] - abc abc 14*11be35a1SLionel Sambuc[abc]b[abd] - abd abd 15*11be35a1SLionel Sambuca(b?c)+d - accd accd 16*11be35a1SLionel Sambuc(wee|week)(knights|night) - weeknights weeknights 17*11be35a1SLionel Sambuc(we|wee|week|frob)(knights|night|day) - weeknights weeknights 18*11be35a1SLionel Sambuca[bc]d - xyzaaabcaababdacd abd 19*11be35a1SLionel Sambuca[ab]c - aaabc abc 20*11be35a1SLionel Sambucabc s abc abc 21*11be35a1SLionel Sambuca* & b @b 22