Re: Extract a pattern from a string

In his reply davido mentions the special arrays @- and @+ which store the start and end character indexes for various matched portions of the string being matched. However, most often those indexes are a means to an end and most often Perl provides better means. It's kind of hard for us to help you find those means however because you've not told us what you want to do. If you take a step back and describe the bigger picture we may be able to offer more help.

True laziness is hard work

Comment on Re: Extract a pattern from a string

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Re^2: Extract a pattern from a string by avim1968 (Acolyte) on Jun 10, 2012 at 09:41 UTC
Hi The BIG picture is very simple i have a list of strings like i showed ME170-5/2/8-ME172-2/2/6-ME4028 ME172-2/1/2-ME196-1/1/3-ME4002 i need to extract from each string the port numbers ie 5/2/8 or 2/2/6 etc.. then according to an index of a number found in the string i need to select the port with the correct index number. for example with the strings above. string 1 = ME170-5/2/8-ME172-2/2/6-ME4028 string 2 = ME172-2/1/2-ME196-1/1/3-ME4002 if my search number is 172 then for string 1 i would get 2/2/6 and for string 2 i would get 2/1/2 thank you Avi	[reply]
Re^3: Extract a pattern from a string by avim1968 (Acolyte) on Jun 10, 2012 at 11:56 UTC
After reading all the answers in this topic i have managed to create my Perl code to do just what i need Thank you ALL :-) Avi	[reply]
Re^3: Extract a pattern from a string by AnomalousMonk (Archbishop) on Jun 10, 2012 at 17:15 UTC
If knowing the position of the port number in the string is necessary in order to be able to work your way back to and extract the index number, there's a more direct way: >perl -wMstrict -le "my $dd = qr{ \d{1,2} }xms; ;; my %indices; for my $s ( 'ME170-5/2/8-ME172-2/2/6-ME4028-FOO172-222/2/666-BAR', 'ME172-2/1/2-ME196-1/1/33-ME4002-11/2/3-ME1-1/22/3-ME22', '1-1/2/3', 'ME-9/9/9-ME', ) { push @{ $indices{$1} }, $2 while $s =~ m{ (\d+) - ($dd (?: / $dd){2}) }xmsg; } ;; for my $i (sort { $a <=> $b } keys %indices) { printf qq{index '$i': port(s) '%s' \n}, join q{' '}, @{ $indices{$i} }; } " index '1': port(s) '1/22/3' '1/2/3' index '170': port(s) '5/2/8' index '172': port(s) '2/2/6' '2/1/2' index '196': port(s) '1/1/33' index '4002': port(s) '11/2/3' [download]	[reply] [d/l]