You will probably need to explain what you mean by "hourglass".

Something like this?

#!/usr/bin/perl -w
use strict;

$|=1;
{
    my @chars = qw(/ - \ | / - \ |);
    my $count;
    sub hourglass {
        print "\r$chars[$count++]";
        $count = 0 if $count == @chars;
    }

}

for (1 .. 100) {
    hourglass();
    sleep 1;
}
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