R help - May 2009 - How could I terminate a script (without leaving R)?

Good morning!
Which is the preferred method to leave a sourced script and returning back to
the '>' prompt?

For example I search for certain files to be processed, but nothing should be
done if they
are not present. Normally I do in my script:
f<-dir(pattern="qq")
if(length(f) > 0) {
    ...process file list...
}
# script end

But I don't like those {} encompassing the whole script so I'm searching
for something to
put in place of the '???' here:
f<-dir(pattern="qq")
if(length(f) == 0) '???'
...process file list...
# script end

Using stop("No file found", call.=F) works, but the Error message is
ugly in this case.

Any suggestion?

Thanks for your help!
			mario

-- 
Ing. Mario Valle
Data Analysis and Visualization Group            | http://www.cscs.ch/~mvalle
Swiss National Supercomputing Centre (CSCS)      | Tel:  +41 (91) 610.82.60
v. Cantonale Galleria 2, 6928 Manno, Switzerland | Fax:  +41 (91) 610.82.82

On 5/28/2009 8:58 AM, Mario Valle wrote:
> Good morning!
> Which is the preferred method to leave a sourced script and returning back
to the '>' prompt?
> 
> For example I search for certain files to be processed, but nothing should
be done if they
> are not present. Normally I do in my script:
> f<-dir(pattern="qq")
> if(length(f) > 0) {
>     ...process file list...
> }
> # script end
> 
> But I don't like those {} encompassing the whole script so I'm
searching for something to
> put in place of the '???' here:
> f<-dir(pattern="qq")
> if(length(f) == 0) '???'
> ...process file list...
> # script end
> 
> Using stop("No file found", call.=F) works, but the Error message
is ugly in this case.
> 
> Any suggestion?
Put the code in a function, call the function as the last line of the 
script, and return from the function when you want to exit the script.

Duncan Murdoch