use strict;

my $info     = "I am a brown icecube";
(my $unknown = $info) =~ tr[a-zA-Z][*];

until($info eq $unknown) {
  print "guess a char: ";

  chomp(my $input = <STDIN>);
  my $c = substr $input => 0, 1;

  next
    if $c !~ /[a-z]/i
       or index($info => $c) == -1;

  substr($unknown => pos($info) - 1, 1) = $c
    while $info =~ /$c/g;

  print $unknown, $/;
}

[download]
So we setup $unknown by assigning $info then replacing all alphabetic characters with asteriks. Then we loop until $info is equal to $unknown i.e when all the characters have been guessed. On every iteration the user is prompted to enter a character, which is read as a line from STDIN and the first character is used. If the given character is not in the alphabet or found in the string, then we reiterate, otherwise we loop through $info looking for $c and replacing the appropriate position in $unknown with $c, then print $unknown.

For more info on the operators and functions used above see. tr, substr, s///, index and pos. If the => is a little confusing it's just the comma in disguise, aka that 'fat comma'.
HTH

_________
broquaint

In reply to Re: string matching/replacing by broquaint
in thread string matching/replacing by Anonymous Monk

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