... the regex syntax to match 4 or more is not quite right. {4,} should be {4,}?. The first version would just match 4 at a minimum, but no more.

The quantifier  {4,} will match as much as possible (while still allowing an overall match), but at least four of the quantified atom. The quantifier  (4,}? will match as little as necessary for an overall match, but at least four of the quantified atom.

c:\@Work\Perl\monks>perl -wMstrict -le "my @strings = qw(vw vwx vwxz vwxzp vwxzpd vwxzpdq); ;; my $consonant = qr{ [bBcCdDfFgGhHjJkKlLmMnNpPqQrRsStTvVwWxXzZ] }xms; ;; for my $s (@strings) { print qq{'$s'}; print qq{{4,} matched; captured '$1'} if $s =~ m{ ($consonant{4,} +) }xms; print qq{{4,}? matched; captured '$1'} if $s =~ m{ ($consonant{4,}? +) }xms; print ''; } " 'vw' 'vwx' 'vwxz' {4,} matched; captured 'vwxz' {4,}? matched; captured 'vwxz' 'vwxzp' {4,} matched; captured 'vwxzp' {4,}? matched; captured 'vwxz' 'vwxzpd' {4,} matched; captured 'vwxzpd' {4,}? matched; captured 'vwxz' 'vwxzpdq' {4,} matched; captured 'vwxzpdq' {4,}? matched; captured 'vwxz'
See perlre, perlretut, and perlrequick.


Give a man a fish:  <%-(-(-(-<


In reply to Re^2: regular expressions by AnomalousMonk
in thread regular expressions by mbgbioinfo

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