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Full Discussion: Grep and map in perl
Top Forums Shell Programming and Scripting Grep and map in perl Post 302473578 by new bie on Sunday 21st of November 2010 01:04:29 PM
Old 11-21-2010
Grep and map in perl
Hi guys,

I'm trying to learn grep and map and having a little problem.

Let's say I have a file which contains:
Apple: abcdcabdadddbac

I want to replace any combinations of three of abcd, thus when I do this:

Code:
print grep {s/[abcd]{3}/X/g} <F>; # will do the subtitution fine, output XXXX

but what if I want to replace [abcd]{3} by a variable $string and enter it on the command line such this:

Code:
grep {s/$string/X/g} <F>;
and when I run: perl test.pl file "bda" # this will not subtitute any combinations of bda, but this exact order only

Can someone tell me what I did wrong here?

Thanks alot,

new bie,
 

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LEARN ABOUT CENTOS

perl::critic::policy::builtinfunctions::requireblockgrep

Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrepUser Contributed Perl DocumentaPerl::Critic::Policy::BuiltinFunctions::RequireBlockGrep(3)

NAME

       Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep - Write "grep { $_ =~ /$pattern/ } @list" instead of "grep /$pattern/, @list".

AFFILIATION

       This Policy is part of the core Perl::Critic distribution.

DESCRIPTION

       The expression forms of "grep" and "map" are awkward and hard to read.  Use the block forms instead.

	   @matches = grep  /pattern/,	  @list;	#not ok
	   @matches = grep { /pattern/ }  @list;	#ok

	   @mapped = map  transform($_),    @list;	#not ok
	   @mapped = map { transform($_) }  @list;	#ok

CONFIGURATION

       This Policy is not configurable except for the standard options.

SEE ALSO

       Perl::Critic::Policy::BuiltinFunctions::ProhibitStringyEval

       Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap

AUTHOR

       Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>

COPYRIGHT

       Copyright (c) 2005-2011 Imaginative Software Systems.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.  The full text of this license
       can be found in the LICENSE file included with this module.

perl v5.16.3							    2014-06-09	       Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep(3)
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