[R] Function call on every prompt

David Winsemius dwinsemius at comcast.net
Fri Nov 19 16:41:36 CET 2010

On Nov 19, 2010, at 10:23 AM, Barry Rowlingson wrote:

> Someone on stackoverflow.com was wondering how to display the current
> time in the R prompt. I could have swore there was a mechanism for
> hooking a function into R such that it is was called before the ">"
> prompt was given, but no amount of searching in R's docs, R's source,
> or RSiteSearch can find it.
> I've searched for 'hook', 'event', 'signal', and various combinations
> of those with 'console', 'prompt', 'after' and 'before' with no joy.
> I'm sure other people have asked this on R-help before, but I can't
> find those messages either.
> Have I been hallucinating or is my search-fu week this Friday?

The question on SO as I understood it was how to get the time on the  
prompt to keep changing without hitting the enter key. The questioner  
had already figured out how to use:

options(prompt=paste(format(Sys.time(), "%H:%M:%S"),"> "))


David Winsemius, MD
West Hartford, CT

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