[R] repeat { readline() }

[Henrik Bengtsson]

Prof Brian Ripley wrote:
> On Sun, 8 Jan 2006, Prof Brian Ripley wrote:
> 
>> Ctrl-Break works: see the rw-FAQ and README.rterm.  (You'll need a return
>> to see a new prompt.)
>>
>> It is related to your reading directly from the console, so Ctrl-C is
>> getting sent to the wrong place, I believe.  (There's a comment from 
>> Guido
>> somewhere in the sources about this, and this seems corroborated by the
>> fact that Ctrl-C will interrupt under Rterm --ess.)
> 
> 
> Although the comment is there (in psignal.c), on closer examination the 
> cause is a change Guido made to getline.c, so Ctrl-C is treated as a 
> character during keyboard input.  I doubt if that was intentional (0 is 
> not the default state) and I have changed it for R-devel.\

Thank you very much this.

Henrik

>>
>> On Sun, 8 Jan 2006, Henrik Bengtsson wrote:
>>
>>> Hi.
>>>
>>> Using Rterm v2.2.1 on WinXP, is there a way to interrupt a call like
>>>
>>>  repeat { readline() }
>>>
>>> without killing the Command window?  Ctrl+C is not interrupting the 
>>> loop:
>>>
>>> R : Copyright 2006, The R Foundation for Statistical Computing
>>> Version 2.2.1 Patched (2006-01-01 r36947)
>>> <snip></snip>
>>>
>>>> repeat { readline() }
>>>
>>> ^C
>>> ^C
>>> ^C
>>> ^C
>>>
>>> On Unix it works.  The problem seems to get the interrupt signal to
>>> "occur" outside the readline() call so that "repeat" is interrupted. 
>>> Doing
>>>
>>> repeat { readline(); Sys.sleep(3) }
>>>
>>> and it is likely that can generate an interrupt signal outside 
>>> readline().
>>>
>>> It seem like readline()/readLines(n=1) or an underlying method catches
>>> the interrupt signal quietly and just waits for a symbol to come
>>> through.  Try readline() by itself and press Ctrl+C.  Maybe this is a
>>> property of the Windows Command terminal, I don't know, but is it a
>>> wanted feature and are R core aware of it?  Note that, in Rgui it is
>>> possible to interrupting such a loop by pressing ESC.
>>>
>>> Cheers
>>>
>>> Henrik
>>>
>>> ______________________________________________
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>>
>> -- 
>> Brian D. Ripley,                  ripley at stats.ox.ac.uk
>> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
>> University of Oxford,             Tel:  +44 1865 272861 (self)
>> 1 South Parks Road,                     +44 1865 272866 (PA)
>> Oxford OX1 3TG, UK                Fax:  +44 1865 272595
>>
>> ______________________________________________
>> R-help at stat.math.ethz.ch mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide! 
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>>
>