simple regexp question

KarthikK has asked for the wisdom of the Perl Monks concerning the following question:

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Re: simple regexp question by jbert (Priest) on Nov 21, 2007 at 10:25 UTC
And to elaborate slightly on why the given solutions work, parens `( )` in a regexp capture their contents to the special variables `$1, $2, ...`. These are numbered according to the order of the capture groups (as ordered by their left hand paren). You can use them (as shown) in the right-hand-side of a search and replace, but they're also valid perl variables which you can make use of after a substitution or ordinary match: `my $line = "furrfu"; $line =~ /(r+)/; print "$line contained ", length($1), " repeated 'r's\n";` [download] Since regexp could in principle overwrite these global special variables, you should make use of them immediately after the regexp and/or save off their values into more appropriateley named vars. (e.g. if you call a subroutine, you don't know if that sub has done a regex and overwritten them). Since parens are used for purposes other than grouping (e.g. to have alternating choices `(foo\|bar\|baz)`, you can use a "non-capturing group", with `(?:)`. Search for 'captur' in perlre for more gory details.	[reply] [d/l] [select]
Re: simple regexp question by cdarke (Prior) on Nov 21, 2007 at 09:45 UTC
Maybe I am reading the question differently, I would go for: `$strTest =~ s/(&.*?);/$1 ;/g;` [download]	[reply] [d/l]
Re: simple regexp question by sen (Hermit) on Nov 21, 2007 at 09:50 UTC
i think, it works, if i understand your reqirement, `$strTest =~ s/(.?)(&)(.?)(;)/$1$2$3 $4/g;` [download]	[reply] [d/l]
Re^2: simple regexp question by KarthikK (Sexton) on Nov 21, 2007 at 10:50 UTC
This pattern seems to work. but i will try and do some more testing with my req. thanks a lot regrads Karthik	[reply]
Re: simple regexp question by andreas1234567 (Vicar) on Nov 21, 2007 at 09:38 UTC
Something like this perhaps? `$ perl -w use strict; my $str = q{sometext with conetnst add kklkk&dfaf:dfaÜÄmlddö;}; $str =~ s/&(.*?);/&$1 ;/g; print $str; __END__ sometext with conetnst add kklkk&dfaf:dfaÜÄmlddö ;` [download] Update: Thanks to johngg for identifying glitch. -- Andreas	[reply] [d/l]
Re^2: simple regexp question by johngg (Canon) on Nov 21, 2007 at 09:49 UTC
Did you mean `$str =~ s/&(.*?);/&$1 ;/g;` [download] perhaps? Your code as it stands seems to lose the text after the ampersand. Cheers, JohnGG	[reply] [d/l]
Re^2: simple regexp question by Punitha (Priest) on Nov 21, 2007 at 10:57 UTC
In customising the andreas1234567 code, you can use it as `use strict; my $str = q{sometext with conetnst add kklkk&dfaf:dfaÜÄmlddö;}; $str =~ s/&([^;]+);/&$1 ;/g; #This includes all the characters til +l the semicolon print $str;` [download] Punitha	[reply] [d/l]