我的一毛钱！Perl 数据类型的玩笑！

# perl -e '$num = "147.2"; $num = 100 * (sprintf "%.2f", $num); print sprintf "%d", $num / 10; print "n"'
1471
# perl -e '$num = "147.2"; $num = 100 * (sprintf "%.2f", $num); print sprintf "%.0f", $num / 10; print "n"'
1472