#    cls();
[download]

You clear the screen too soon. You should store the results in a variable, then print after the cls.

Also, the game continues even if someone wins. You need an exit condition.

I got a draw with this sequence: 123465798

See also: Basic debugging checklist

Check out Conditional Operator for assigning to $player.

You use a for loop for the moves, which will always execute the contents of the loop 9 times. Most of the time, you don't need that many. There is a way to break out of the loop, but the more conventional method is to have something like:

my $win = 0;
my $i = 0;
do {
     $i += 1;
     printf "Player %d's turn:\n",2-$i%2;
   # game code here
   # when a winning move is detected:
     $win = 1;
} until (($win) || ($i == 9));
printf "%s won\n", $win ? sprintf "Player %d",2-$i%2 : "Nobody";
[download]

Thanks for the help. I did end up getting the program to exit after a winner was declared. However, I couldn't figure out how to get the draw condition working right. I had to work tonight and the assignment was due by midnight so I just went ahead and submitted what I had. GotToBTru I tried what you said but couldn't get it just right but I did take something from your advice. I also took toolic's exit condition advice. It mostly works so I'm happy. Here's what I ended up with. Thanks again.

#!/usr/bin/perl
use strict;
use warnings;

# Create the game board

my @board = qw/_ _ _ _ _ _ _ _ _/;

print "
 _____
|$board[0]|$board[1]|$board[2]|
|$board[3]|$board[4]|$board[5]|
|$board[6]|$board[7]|$board[8]|\n
";

# Create a variable to store who the winner is
my $winner = "Cat";

# A subroutine to clear the screen
sub cls()
{
    system $^O eq 'MSWin32' ? 'cls' : 'clear';
}

# Print directions for the user

print "X plays first. Please type one of the numbers for each of your 
+moves.\n";
print " 1 2 3
 4 5 6
 7 8 9.\n";

# Use a for loop, and loop through 9 moves for the game

for (my $i = 0; $i < 9; $i++)
{
        
    
 #create a player variable, and using % 2, assign it as X or O
 
 my $player = "";
 
 if ($i % 2)
     {
         $player = "O";
     }
     
     else 
     {
         $player = "X";
     }

    # Using a while loop, get the player's move and make sure it is va
+lid
    my $input = 0;
    my $error = "";
    my $win = 0;

    while ($input < 1 || $input > 9)
    {
        print  $error;
        print "Enter your play.\n";
        $input = <STDIN>;
        chomp $input;
        $error = "Invalid move.\n";
    }
    
    $input = $input -1;
    if ($board[$input] ne 'X' and $board[$input] ne 'O')
    {
        $board[$input] = $player;
    } 
    else 
    {
        $i--;
        print "Play is already selected.";
    }
        
        
    # If this is move 5+, check for a winner
    if ($i > 4)
    {
        
    }
            
     if ($board[0] ne "_" and $board[1] eq $board[2] and $board[0] eq 
+$board[2])
    {
        $win = 1;
    }
    
    elsif ($board[3] ne "_" and $board[4] eq $board[5] and $board[3] e
+q $board[5])
    {
        $win = 1;
    }
        
    elsif ($board[6] ne "_" and $board[7] eq $board[8] and $board[6] e
+q $board[8])
    {
        $win = 1;
    }
    
    elsif ($board[0] ne "_" and $board[3] eq $board[6] and $board[0] e
+q $board[6])
    {
        $win = 1;
    }
    
    elsif ($board[1] ne "_" and $board[4] eq $board[7] and $board[1] e
+q $board[7])
    {
        $win = 1;
    }
    
    elsif ($board[2] ne "_" and $board[5] eq $board[8] and $board[2] e
+q $board[8])
    {
        $win = 1;
    }
    
    elsif ($board[0] ne "_" and $board[4] eq $board[8] and $board[0] e
+q $board[8])
    {
        $win = 1;
    }
    
    elsif ($board[6] ne "_" and $board[4] eq $board[2] and $board[6] e
+q $board[2])
    {
         $win = 1;
        
    }

    
    
    cls();
    print "
 _____
|$board[0]|$board[1]|$board[2]|
|$board[3]|$board[4]|$board[5]|
|$board[6]|$board[7]|$board[8]|\n
";

if ($win == 1)
    {
    print "$player Wins!\n";
    exit;
    }
}
[download]

While this might be too late for your submission of code, I still would like to propose a slightly different approach. At the center of my proposal is a list of all the possible lines (rows, columns and diagonals) that constitute a potential win. This way you can replace your if, elsif chain with a loop. Secondly, I would count the Xs, Os and blanks for each line and then decide whether or not there is a win or a draw situation. It could look like this:

use strict;
use warnings;

my @board = qw( O X O 
                X X O 
                O O X );

my @tests = ( 
    # rows
    [ 0, 1, 2 ],
    [ 3, 4, 5 ],
    [ 6, 7, 8 ],
    # columns
    [ 0, 3, 6 ],
    [ 1, 4, 7 ],
    [ 2, 5, 8 ],
    # diagonals
    [ 0, 4, 8 ],
    [ 2, 4, 6 ] 
    );

# testing for win and draw
my $win  = 0;
my $draw = 1;
for my $line ( @tests ) {
    my %symbols = ( _ => 0, X => 0, O => 0 );
    # count occurences of each symbol
    $symbols{$board[$_]}++ for @$line;
    # test for winning
    if( $symbols{'X'}==3 or $symbols{'O'}==3 ) {
        $win = 1;
        $draw = 0;
        last;
    }
    # test for "open lines"
    if( $symbols{'X'}==0 or $symbols{'O'}==0 ) {
        $draw = 0;
    }   
}

print "Win: $win, draw: $draw\n";
[download]