match 3 or more carriage returns... maybe like this? =~ m/\n{3,}/ ... so expanding the script provided from GrandFather 
while (<>) {
        s/\n\n/\n/gs;
        print;
    }

[download]
while (<>) {
next if $_ =~ m/\n{1}/;
if ($_ =~ m/\n{2}){s/\n{2}/\n/gs}
elsif ($_ =~ m/\n{3,}){s/\n{3,}/\n\s/gs}
}

[download]
or something like this...

In reply to Re: Removing double carriage return by pvaldes
in thread Removing double carriage return by dragooneye

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