# As suggested by toolic above
use strict;
use warnings;



print "Please enter the file name you want the word count\n\n";
my $file= <STDIN>;

chomp $file;


# Lexical file handles (my $fh) are better than file globs.
# Also, three-argument open() is better than two-argument open().
open(my $fh, "<", $file) or die $!;

my %u_wc;
my $words = 0;             # Don't forget to declare $word!
while (<$fh>){
        my @words = split;
        $words += @words;
        $u_wc{$_}++ for @words;
}

# print ("The number of words in the file is $words\n\n");
# The parens are useless here, and also inconsistent with the print statement
# that prompted us for a file name.
print "The number of words in the file is $words\n\n";

# print ("this are the unique words $u_wc\n\n");
# $u_wc isn't a variable. We do have %u_wc though.

print "These are the unique words: ", join(" ", keys %u_wc), "\n\n";