[Rd] Spurious output white line in R script (PR#8631)

[Simon Urbanek]

On Feb 23, 2006, at 11:14 AM, Thomas Lumley wrote:

> On Thu, 23 Feb 2006, Prof Brian Ripley wrote:
>
>> On Wed, 22 Feb 2006, François Pinard wrote:
> [...]
>>> So, I was not expecting R, running with that option activated, to
>>> "volunteer" white lines. :-)
>>
>> But Simon said `with the documentation'.  Not doing what you  
>> expected is
>> not a bug.  Can you please point us to documentation which says that
>> end-of-file produces no output?
>>
>> This does appear to be deliberate behaviour from
>>
>> void end_Rmainloop(void)
>> {
>>    Rprintf("\n");
>>    /* run the .Last function. If it gives an error, will drop back  
>> to main
>>       loop. */
>>    R_CleanUp(SA_DEFAULT, 0, 1);
>> }
>>
>> and I think it is necessary, as R might well have a partial line  
>> of output queued up for the console.  So this is probably `as  
>> quietly as possible'.
>
> (While agreeing entirely on the "bug" issue), couldn't we have  
> fflush() instead of sending a newline?
>

It's not really about fflush - the rationale is to not leave non- 
terminated lines on the output before quitting via EOF, which has its  
merits. If you remove it, you get this:
...
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

 > caladan:Rdev$

instead of

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

 >
caladan:Rdev$

fflush won't change this.

Cheers,
Simon