Hi Jeroen, I think `pipe` might just be returning the status code of the underlying command executed; for example, I get a status code of '0' when I test a pipe on `ls`:
conn <- pipe("ls") stream <- readLines(conn) print(close(conn)) Similarly, I get an error code if I try to `ls` a non-existent directory (512 in my case), e.g. conn <- pipe("ls /no/path/here/sir") stream <- readLines(conn) print(close(conn)) So maybe `cat` just doesn't set a status code, and so there's nothing for R to forward back (ergo -- NULL)? Kevin On Wed, May 13, 2015 at 5:24 PM, Jeroen Ooms <jeroen.o...@stat.ucla.edu> wrote: > Is there a way to get the status code of a pipe() command? The > documentation suggests that it might be returned by close, however > this does not seem to be the case. > > con <- pipe("cat /etc/passwd", "r") > stream <- readLines(con, n = 10) > err <- close(con) > print(err) > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel