pls explain following syntax

manish.rathi has asked for the wisdom of the Perl Monks concerning the following question:

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Re: pls explain following syntax by ikegami (Patriarch) on Apr 05, 2009 at 06:22 UTC
You'll have better luck if you put your code in `<c>...</c>` tags. `$line =~ /^([^,]),(.)$/` matches any string with a comma in it. It captures everything before the first comma, and everything after the first comma. `$flat_file =~ m!^.*/([^/]+)$!){ $flat_file = $1;}` should be replaced with `use File::Basename qw( fileparse ); $flat_file = fileparse($flat_file);` [download] File::Basename	[reply] [d/l] [select]
Re: pls explain following syntax by Anonymous Monk on Apr 05, 2009 at 06:38 UTC
Have you read perlintro yet? use YAPE::Regex::Explain; print YAPE::Regex::Explain->new(qr/^([^,]),(.)$/)->explain; print YAPE::Regex::Explain->new(qr!^./([^/]+)$!)->explain; __END__ The regular expression: (?-imsx:^([^,]),(.)$) 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: ---------------------------------------------------------------------- [^,] any character except: ',' (0 or more times (matching the most amount possible)) ---------------------------------------------------------------------- ) end of \1 ---------------------------------------------------------------------- , ',' ---------------------------------------------------------------------- ( group and capture to \2: ---------------------------------------------------------------------- .* any character except \n (0 or more times (matching the most amount possible)) ---------------------------------------------------------------------- ) end of \2 ---------------------------------------------------------------------- $ before an optional \n, and the end of the string ---------------------------------------------------------------------- ) end of grouping ---------------------------------------------------------------------- The regular expression: (?-imsx:^./([^/]+)$) 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 ---------------------------------------------------------------------- . any character except \n (0 or more times (matching the most amount possible)) ---------------------------------------------------------------------- / '/' ---------------------------------------------------------------------- ( group and capture to \1: ---------------------------------------------------------------------- [^/]+ any character except: '/' (1 or more times (matching the most amount possible)) ---------------------------------------------------------------------- ) end of \1 ---------------------------------------------------------------------- $ before an optional \n, and the end of the string ---------------------------------------------------------------------- ) end of grouping ---------------------------------------------------------------------- [download]	[reply] [d/l]