fig08_11.pl

来自「PERL语言资料 可以用于PERL程序设计」· PL 代码 · 共 47 行

#!usr/bin/perl
# Fig 8.11: fig08_11.pl
# Using backreferencing to find palindromes.

use strict;
use warnings;

my $string1 = "madam im adam";
my $string2 = "the motto means something";
my $string3 = "no palindrome here";

findPalindrome( $string1 );
findPalindrome( $string2 );
findPalindrome( $string3 );

sub findPalindrome
{
   my $string = shift();

   if ( $string =~ 
           /(\w)\W*(\w)\W*(\w)\W*(\w)\W*\4\W*\3\W*\2\W*\1/ 
        or $string =~ 
           /(\w)\W*(\w)\W*(\w)\W*(\w)\W*\3\W*\2\W*\1/ ) {
      print "$string - ",
            "has a palindrome of at least 7 characters.\n";
   }
   else {
      print "$string - has no long palindromes.\n";
   }
}

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