The problem is line 17, that "else" at line 17 has nothing to match, all the brackets before that line matched perfectly.

Had you well indented your code, you probably figured out this yourself:

if ( exists $list{$location} ) {
    my $value = $list{$location};
    $value++;

    $list{$location} = $value;
} elsif ( $list{$location} eq "" ) {
    if ( exists $list{Unknown} ) {
        my $value = $list{Unknown};
        $value++;
        $list{Unknown} = $value;
    }
} else {
        $list{Unknown} = "1";
}
=document
    else {
        $list{$location} = "1";
    }
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How to fix? it really depends on what you want, and I don't want to second guess.

By looking at the exsiting code, the logic looks broken. I don't think it will ever run into that elsif branch. If $list{$location} eq "", obviously exists($list{$location}).

my $value = $list{$location};
$value++;
$list{$location} = $value;
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$list{$location}++;
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$list{ $location || 'Unknown' }++;
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I don't understand how you can't figure out what line the error is on. Read the error, it tells you:

tom@wintermute tom $ perl -c t
syntax error at t line 17, near "else"
t had compilation errors.
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perl -cwTM-strict ./yourscript.pl
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You might need XEmacs that points you all the ({[ pairs for easy visualizing them. There are also other editors that do the same. But XEmacs, once you get used to it looks very much more an expert in perl than oneself :) .

By using -w at the starting line:

#!/use/bin/perl -w
##and followed by 
use strict;
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Might help a lot. But remember that you might need to add some more conditionals to your sentences:

if (($location) && exists($list{$location})) {
    my $value = $list{$location};
    $value++;

    $list{$location} = $value if ($value);
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...for example, just to illustrate the use of verified existing variables.

But then, the error messages are very descriptive and easy to track down.