Extract Sub String

gvinu4u has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Extract Sub String by Ratazong (Monsignor) on Jun 21, 2011 at 06:08 UTC
`if ($string =~/(.*?)\"_RVCT"/)` [download] Why do you have the `\"` in your regex? Remove it! And while you are at it, also remove the other `"` in your regex (that is not part of your $string itself, but the delimiter for perl)	[reply] [d/l] [select]
Re^2: Extract Sub String by gvinu4u (Acolyte) on Jun 22, 2011 at 10:54 UTC
Thanks a lot I did exactly what you told	[reply]
Re: Extract Sub String by alfie (Pilgrim) on Jun 21, 2011 at 07:12 UTC
Actually you might want to take a look at Death to Dot Star! why you shouldn't use .* in regexps, not even with ?. Also, there is no " in your screen, so there is no need to match it. Also, " is not a special character inside a regex. As a general advice, you might want to read up the perlre manual again. -- use signature; signature(" So long\nRhonda");	[reply]
Re: Extract Sub String by toolic (Bishop) on Jun 21, 2011 at 15:00 UTC
Tip #9 from the Basic debugging checklist is to use YAPE::Regex::Explain to demystify Perl regular expressions: The regular expression: (?-imsx:(.?)"_RVCT") 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: ---------------------------------------------------------------------- .? any character except \n (0 or more times (matching the least amount possible)) ---------------------------------------------------------------------- ) end of \1 ---------------------------------------------------------------------- "_RVCT" '"_RVCT"' ---------------------------------------------------------------------- ) end of grouping ---------------------------------------------------------------------- [download]	[reply] [d/l]
Re^2: Extract Sub String by gvinu4u (Acolyte) on Jun 22, 2011 at 10:50 UTC
Thanks to all finally I got this working `my ( $filename ) = $line =~ /(.*?)_RVCT/;` [download]	[reply] [d/l]
Re: Extract Sub String by sanku (Beadle) on Jun 21, 2011 at 11:52 UTC
Hi, Try this one... `$string = "Viood_ram_shiva_RVCT22"; if ($string =~/(\w+)(_RVCT)/) { print "The file name is $1. "; }` [download]	[reply] [d/l]
Re^2: Extract Sub String by toolic (Bishop) on Jun 21, 2011 at 12:58 UTC
if ($string =~/(\w+)(_RVCT)/) There is no need for the capturing parentheses around `_RVCT`: `use warnings; use strict; my $string = "Viood_ram_shiva_RVCT22"; if ($string =~ /(\w+)_RVCT/) { print "The file name is $1. "; }` [download]	[reply] [d/l] [select]