in reply to Help with regexes
If you have time you might want to peruse the documentation on regexes in general at perlreftut and perlre).
As you might run into more regular expressions you might want to look into using YAPE::Regex::Explain which makes deciphering Regexes easy for instance
will return the following for your first regex:perl -MYAPE::Regex::Explain -e 'print YAPE::Regex::Explain->new(qr/^(\ +s^+)MVA/o)->explain;'
and then for the second one:The regular expression: (?-imsx:^(\s^+)MVA) matches as follows: NODE EXPLANATION ---------------------------------------------------------------------- (?-imsx: group, but do not capture (case-sensitive) (with ^ and $ matching normally) (with . not matching \n) (matching whitespace and # normally): ---------------------------------------------------------------------- ^ the beginning of the string ---------------------------------------------------------------------- ( group and capture to \1: ---------------------------------------------------------------------- \s whitespace (\n, \r, \t, \f, and " ") ---------------------------------------------------------------------- ^+ the beginning of the string (1 or more times (matching the most amount possible)) ---------------------------------------------------------------------- ) end of \1 ---------------------------------------------------------------------- MVA 'MVA' ---------------------------------------------------------------------- ) end of grouping ----------------------------------------------------------------------
perl -MYape::Regex::Explain -e 'print YAPE::Regex::Explain->new(qr/(\s ++)/o)->explain;' The regular expression: (?-imsx:(\s+)) matches as follows: NODE EXPLANATION ---------------------------------------------------------------------- (?-imsx: group, but do not capture (case-sensitive) (with ^ and $ matching normally) (with . not matching \n) (matching whitespace and # normally): ---------------------------------------------------------------------- ( group and capture to \1: ---------------------------------------------------------------------- \s+ whitespace (\n, \r, \t, \f, and " ") (1 or more times (matching the most amount possible)) ---------------------------------------------------------------------- ) end of \1 ---------------------------------------------------------------------- ) end of grouping ----------------------------------------------------------------------
HTH
-enlil
|
|---|