编辑代码

print "Enter a temperature in Celsius \n";
$celsius = <STDIN>;
chomp($celsius);
if($celsius =~ m/^[0-9]+$/){
  $fahrenheit = ($celsius * 9/5) +32;
  print "$celsius ℃ is $fahrenheit ℉ \n";
} else {print "Excepting a number, so I don't understand \"$celsius\". \n";
}