1 #!/usr/bin/perl
 2 use 5.018;
 3 
 4 my @word;
 5 my @sentence;
 6 
 7 my $pattern = "[A-Za-z\-]";
 8 
 9 say "Input the file name:";
10 chomp (my $fileName = <STDIN>);
11 open FIN, $fileName;
12 
13 while (<FIN>)
14 {
15     chomp;
16     if (/ \[ (${pattern}+) \] /x)
17     {
18         my $curWord = $1;
19         my $underline = ($curWord =~ s/$pattern/_/rg);
20         push @word, $curWord;
21         push @sentence, (s/ \[ $curWord \] /$underline/rx);
22     }
23 }
24 close FIN;
25 
26 my $id;
27 my ($rightCnt, $wrongCnt);
28 say "\nGuess the word according to context.";
29 say "Hint: Case of letters does not matter.";
30 say "Hint: you can input a question mark to give up.";
31 &getNext;
32 
33 while (1)
34 {
35     chomp (my $ans = <STDIN>);
36     if ($ans =~ /\b $word[$id] \b/xi) 
37     {
38         printf "Right! Right/Wrong = %d/%d\n", ++$rightCnt, $wrongCnt;
39         &getNext;
40     }
41     elsif ($ans eq "?")
42     {
43         printf "Give up. Right/Wrong = %d/%d\n", --$rightCnt, ++$wrongCnt;
44         say "The answer is: $word[$id]";
45         &getNext;
46     }
47     else
48     {
49         say "Wrong!";
50         ++$wrongCnt;
51         redo;
52     }
53 }
54 
55 sub getNext
56 {
57     state $N = 0;
58     $id = int (rand @word);
59     printf "Problem #%d: %s (%d words)\n", ++$N, $sentence[$id], length $word[$id];
60 }