Re: [R] handling a cancelled file.choose()

From: Deepayan Sarkar <>
Date: Wed, 06 Jun 2007 12:09:52 -0700

On 6/6/07, Ben Tupper <> wrote:
> Hello,
> I have a file reading function that prompts the user with a file dialog
> if a filename is not provided in the argument list. It is desirable to
> return gracefully if the user selects "Cancel", but file.choose() throws
> an error instead of returning something like a character.
> > file.choose()
> [1] "/Users/ben/ben_idl.pref"
> > file.choose()
> Error in file.choose() : file choice cancelled
> I naively planned to use nchar() to test the length, assuming
> cancellation would return a zero-length character. That appears to be
> out of the question. [...]

Not really, errors can be caught and handled. This seems to give the behaviour you want:

tryCatch(file.choose(), error = function(e) "")

-Deepayan mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Wed 06 Jun 2007 - 19:43:35 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Wed 06 Jun 2007 - 20:33:33 GMT.

Mailing list information is available at Please read the posting guide before posting to the list.