Perl程式碼片段-Regex測試程式

參考《Perl語言入門》的一個Regex簡單測試程式：

 1 #!/usr/bin/perl 2 use warnings; 3 use strict; 4  5 my $pattern=$ARGV[0]; 6 if(not $pattern){ 7     print "Usage: ./ret.pl PATTERN\n"; 8     exit; 9 }10 print "The pattern is m{$pattern}.\n";11 print "Ctrl + D to exit.\n";12 print ">";13 while(<STDIN>){14     chomp(my $line = $_);15     if($line =~ m{$pattern}){16         print "matched: '$`<$&>$''.\n";17     } else {18         print "not matched.\n";19     }20     print ">";21 }