sink diverts R output to a connection. sink.number() reports how many diversions are in use.
sink.number(type = "message") reports the number of the
connection currently being used for error messages.
sink(file = NULL, append = FALSE, type = c("output", "message"), split = FALSE)
sink.number(type = c("output", "message"))NULL to stop sink-ing.TRUE, output will be appended to
file; otherwise, it will overwrite the contents of
file.TRUE, output will be sent to the new
sink and to the current output stream, like the Unix program tee.sink returns NULL.For sink.number() the number (0, 1, 2, ...) of diversions of
output in place.For sink.number("message") the connection number used for
messages, 2 if no diversion has been used.
sink for any other
purpose. The software will stop you closing one such inadvertently. Do not sink the messages stream unless you understand the source code
implementing it and hence the pitfalls.sink diverts R output to a connection. If file is a
character string, a file connection with that name will be established
for the duration of the diversion. Normal R output (to connection stdout) is diverted by
the default type = "output". Only prompts and (most)
messages continue to appear on the console. Messages sent to
stderr() (including those from message,
warning and stop) can be diverted by
sink(type = "message") (see below).
sink() or sink(file = NULL) ends the last diversion (of
the specified type). There is a stack of diversions for normal
output, so output reverts to the previous diversion (if there was
one). The stack is of up to 21 connections (20 diversions).
If file is a connection it will be opened if necessary (in
"wt" mode) and closed once it is removed from the stack of
diversions.
split = TRUE only splits R output (via Rvprintf) and
the default output from writeLines: it does not split
all output that might be sent to stdout().
Sink-ing the messages stream should be done only with great care.
For that stream file must be an already open connection, and
there is no stack of connections.
If file is a character string, the file will be opened using
the current encoding. If you want a different encoding (e.g. to
represent strings which have been stored in UTF-8), use a
file connection --- but some ways to produce R output
will already have converted such strings to the current encoding.
Chambers, J. M. (1998) Programming with Data. A Guide to the S Language. Springer.
capture.outputsink("sink-examp.txt")
i <- 1:10
outer(i, i, "*")
sink()
unlink("sink-examp.txt")
## capture all the output to a file.
zz <- file("all.Rout", open = "wt")
sink(zz)
sink(zz, type = "message")
try(log("a"))
## back to the console
sink(type = "message")
sink()
file.show("all.Rout")
Run the code above in your browser using DataLab