On Mon, 17 Jun 2019, ND via Pcre-dev wrote: > PCRE2 version 10.33 2019-04-16 > /(?<=.{2}(?<=.{6}))/info > Capture group count = 0 > Max lookbehind = 6 > May match empty string > Subject length lower bound = 0 > abc\=ph > No match > > > Expected maxlookbehind=4, not 6.
Why do you expect 4? The matcher goes back 2, then matches two characters, so it is back at the start. Then it goes back 6. PCRE2 version 10.34-RC1 2019-04-22 re> /(?<=.{2}(?<=.{6}))/ ------------------------------------------------------------------ 0 29 Bra 3 23 AssertB 6 2 Reverse 9 Any{2} 13 10 AssertB 16 6 Reverse 19 Any{6} 23 10 Ket 26 23 Ket 29 29 Ket 32 End ------------------------------------------------------------------ Consider also: PCRE2 version 10.34-RC1 2019-04-22 /(?<=a{2}(?<=[ab]{6}))(.*)/ bbbbaaXXX 0: XXX 1: XXX cbbbaaXXX No match The successful match looked back 6 characters before XXX. Philip -- Philip Hazel -- ## List details at https://lists.exim.org/mailman/listinfo/pcre-dev