This doesn't work for me, perl 5.8.6 on OS X, however with a little change it does: 
for ( -0.1, -0.01, -0.001, -0.0001, -0.00001, -10, ) {
    my $num = sprintf "%0.1f", $_;
    $num = abs( $num ) if $num == 0;
    printf "%s --> %0.1f\n", $_, $num;
}

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In reply to Re^2: Negative zero? There's gotta be a sprintf that undoes that, right? by duckyd
in thread Negative zero? There's gotta be a sprintf that undoes that, right? by rgiskard

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