?try

df <- try(read.table(...))
if (inherits(df, 'try-error')){  what to do if file empty }

On Fri, Jan 1, 2010 at 3:55 PM, Ted Harding <Ted.Harding@manchester.ac.uk>wrote:

> On 01-Jan-10 20:41:52, Peng Yu wrote:
> > read.table terminates the program if the input file is empty. Is there
> > way to let the program continue and return me a NULL instead of
> > terminating the program?
> >
> > $ Rscript read_empty.R
> >> read.table("empty_data.txt")
> > Error in read.table("empty_data.txt") : no lines available in input
> > Execution halted
> > $ cat read_empty.R
> > read.table("empty_data.txt")
> > $ cat empty_data.txt; echo EOF
> > EOF
>
> If I understand the point of your query correctly, the following,
> from "?read.table", would be relevant:
>
> Value:
>  A data frame (?data.frame?) containing a representation of the
>  data in the file.
>
>  Empty input is an error unless "col.names" is specified, when a
>  0-row data frame is returned: similarly giving just a header line
>  if "header = TRUE" results in a 0-row data frame.  Note that in
>  either case the columns will logical unless ?colClasses? was
>  supplied.
>
> The result would not be NULL, but can be tested for zero rows.
>
> Hoping this helps,
> Ted.
>
> --------------------------------------------------------------------
> E-Mail: (Ted Harding) <Ted.Harding@manchester.ac.uk>
> Fax-to-email: +44 (0)870 094 0861
> Date: 01-Jan-10                                       Time: 20:55:35
> ------------------------------ XFMail ------------------------------
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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