Capturing warnings with capture.output

Something like this which displays the warnings and also writes
them to out so that they are captured:

out <- capture.output(
   withCallingHandlers({
        print(1)
        warning("A warning.")
        print(2)
        warning("Another warning.")
        print(3)
   }, warning = function(x) cat(x$message, "\n"))
)

print(out)


On 8/29/06, hadley wickham <h.wickham at gmail.com> wrote:

Is there any way to include warnings in the output from capture.output?  eg:

a <- capture.output(warning("test"))
all.equal(a, "Warning message: \n test ")

Conceptually, this seems like redirecting stderr to stdout, or somehow
changing warning to simple print it's output.  I've had a look at
tryCatch and using a warning handler, but this terminates execution at
the warning.

Thanks,

Hadley