R help - Nov 2001 - Summary --- testing for existence of file.

Many thanks to those who answered my question about how to test
for the existence of a file:  Berwin Turlach, Jari Oksanen, Henrik
Bengtsson, Uwe Ligges, and Joerg Maeder.

The simplest solution is to use the built-in (!!!) function
file.exists() which returns TRUE if the file exists, and FALSE
if it doesn't.  Like, duhhhhhh!!!  It's exactly what I wanted.

Special thanks to Berwin Turlach who explained to me how I might
have found out about file.exists() for my own self ---
> 1.) In R type help.start().
> 2.) Go to browser and select "Search Engine & Keywords".
> 3.) Enter "file" as search keyword and press the search button
> 4.) Peruse the list of hits until something suitable comes up
A couple of suggestions to the developers:

	1) It would nice for us bunnies if, say, help.search() made
	a suggestion to do Berwin's four steps if help.search()
	itself turns up nothing useful.

	2) The ``See also'' for file.access et al. should include
	``files'' which contains the documentation on a whole
	elephantful of useful functions.  The item ``files'' comes
	last in the items of the list turned up by the search wherein
	the word ``file'' actually appears in the link.  The faint
	of heart might well become discouraged before getting there.
        I also think that an explicit link from file.access to
	file.exists (the two are closely related) would be helpful.

Thanks again to all my enlighteners.

					cheers,

						Rolf Turner
						rolf at math.unb.ca
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> 	1) It would nice for us bunnies if, say, help.search() made
> 	a suggestion to do Berwin's four steps if help.search()
> 	itself turns up nothing useful.
As a fellow bunny, I have to add: if Berwin's 4 steps don't turn
up what you want, or give you so many anwers you don't know what to
do, the next (unoffical) step is to go to Jonathan Baron's R
documentation search engine:

http://finzi.psych.upenn.edu/search.html

This has the docs, *and* the archives of the r-help discussion list.
Nice!  (thanks, Jonathan!)  Jonathan has announced it on r-help 
before, but it really needs to be crowed about.  Punching 
"existance file"  into the search came up with 27 hits; item
five was a similar discussion group thread in June 2000 that 
gave the same answer (thread: [R] Checking the existence of a file)

Cheers

Jason
-- 
Indigo Industrial Controls Ltd.
64-21-343-545
jasont at indigoindustrial.co.nz
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