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Top Forums Shell Programming and Scripting Perl - Use of *? in Matching Pattern Post 302945220 by jnrohit2k on Wednesday 27th of May 2015 10:44:01 AM
Old 05-27-2015
Perl - Use of *? in Matching Pattern

I am using Perl version 5.8.4 and trying to understand the use of regular expression. Following is my code and output.

Code:
 
 $string = "Perl is a\nScripting language";
 ($start) = ($string =~ /\A(.*?) /);
 @lines = ($string =~ /^(.*?) /gm);
 print "First Word (using \\A): $start\n","Line Starts (using ^): @lines\n";

Output:-
First Word (using \A): Perl
Line Starts (using ^): Perl Scripting

I know
* (star) is used to 'Matches 0 or more occurrence of preceding expression'.
? (question mark) is used to 'Matches 0 or 1 occurrence of preceding expression'.

But I did not understand how both (*?) are working together in above piece of code.

Thanks!
 

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PPI::Token::Word(3)					User Contributed Perl Documentation				       PPI::Token::Word(3)

NAME
PPI::Token::Word - The generic "word" Token INHERITANCE
PPI::Token::Word isa PPI::Token isa PPI::Element DESCRIPTION
A "PPI::Token::Word" object is a PPI-specific representation of several different types of word-like things, and is one of the most common Token classes found in typical documents. Specifically, it includes not only barewords, but also any other valid Perl identifier including non-operator keywords and core functions, and any include "::" separators inside it, as long as it fits the format of a class, function, etc. METHODS
There are no methods available for "PPI::Token::Word" beyond those provided by its PPI::Token and PPI::Element parent classes. We expect to add additional methods to help further resolve a Word as a function, method, etc over time. If you need such a thing right now, look at Perl::Critic::Utils. literal Returns the value of the Word as a string. This assumes (often incorrectly) that the Word is a bareword and not a function, method, keyword, etc. This differs from "content" because "Foo'Bar" expands to "Foo::Bar". method_call Answers whether this is the name of a method in a method call. Returns true if yes, false if no, and nothing if unknown. TO DO
- Add "function", "method" etc detector methods SUPPORT
See the support section in the main module. AUTHOR
Adam Kennedy <adamk@cpan.org> COPYRIGHT
Copyright 2001 - 2011 Adam Kennedy. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of the license can be found in the LICENSE file included with this module. perl v5.16.3 2011-02-26 PPI::Token::Word(3)
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