Function call on every prompt

On 19/11/2010 10:31 AM, Marc Schwartz wrote:

On Nov 19, 2010, at 9:23 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?

Barry was probably remembering SweaveHook.

 Barry

Baz,

What's wrong with:

 options(prompt = paste(format(Sys.time(), "%a %b %d %X %Y %Z"), ">"))

Fri Nov 19 09:30:53 2010 CST>
Fri Nov 19 09:30:53 2010 CST>
Fri Nov 19 09:30:53 2010 CST>

That one doesn't get updated with every prompt.

Duncan Murdoch