参考《Perl语言入门》的一个正则表达式简单测试程序：

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(
     
      ){14     chomp(my $line = $_);15     if($line =~ m{
   $pattern}){16         print "matched: '$`<$&>$''.\n";17     } else {18         print "not matched.\n";19     }20     print ">";21 }