Smartest way to read a number?

[Kai Meyer]

I don't get the exception on Linux after a new line, I have to wait 
until EOF, which is typically the end of the program if reading from 
STDIN. Not very useful.

import std.stdio;

T readNumber(T)()
{
     T result;
     stdin.readf("%s", &result);
     return result;
}
void main()
{
     try
     {
         int n = readNumber!int();
         writeln(n);

         float f = readNumber!float();;
         writeln(f);
     }
     catch(Exception e)
     {
         writeln(e.msg);
     }
}


Sample execution:
-----------------------
[kai.meyer at kai-rhel6 D]$ dmd -run readnum.d
a
1
1.2
** I hit Ctrl-D here, so this line isn't part of the output ***
std.conv(1157): Can't convert value `a
1
1.2
' of type LockingTextReader to type int
-----------------------

Or if you prefer with out my terminal echoing my input:
-----------------------
[kai.meyer at kai-rhel6 D]$ echo -e 'a\n1\n1.2\n' | dmd -run readnum.d
std.conv(1157): Can't convert value `a
1
1.2

' of type LockingTextReader to type int
----------------------


On 11/10/2011 02:58 PM, Tobias Brandt wrote:
> import std.stdio;
>
> T readNumber(T)()
> {
>      T result;
>      stdin.readf("%s",&result);
>      return result;
> }
>
> Throws a ConvException if the input string wasn't in the right format.
>
> On 10 November 2011 22:48, Fabian<talk2fab at online.de>  wrote:
>> Hey guys.
>>
>> I just want to write a few console applications. Usualy I have to read numbers
>> to calculate some values. But what's the smartest way to read and convert the
>> input?
>>
>> I've coded these lines:
>>
>> import std.stdio, std.string, std.conv;
>>
>> T readNumber(T)()
>> {
>>         string buffer;
>>         stdin.readln(buffer);
>>         buffer = chomp(buffer);
>>
>>         if(isNumeric(buffer))
>>         {
>>                 return parse!T(buffer);
>>         }
>>         else
>>         {
>>                 throw new Exception("Input is not a number!");
>>         }
>> }
>>
>> void main()
>> {
>>         try
>>         {
>>                 int n = readNumber!int();
>>                 writeln(n);
>>
>>                 float f = readNumber!float();
>>                 writeln(f);
>>         }
>>         catch(Exception e)
>>         {
>>                 writeln(e.msg);
>>         }
>> }
>>
>> Can I use that function or is there a cleaner way to do this job?
>>
>> Greetings
>> Fabian
>>