| sink {base} | R Documentation |
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"))
file |
a connection or a character string naming the
file to write to, or NULL to stop sink-ing. |
append |
logical. If TRUE, output will be appended to
file; otherwise, it will overwrite the contents of
file. |
type |
character. Either the output stream or the messages stream. |
split |
logical: if TRUE, output will be sent to the new
sink and to the current output stream, like the Unix program tee. |
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 is diverted by the default type = "output".
Only prompts and warning/error messages continue to appear on the terminal.
The latter can diverted by 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.
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.
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.
Don't use a connection that is open for 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(split = TRUE) is only available on systems which support
the C99 function va_copy (or under the name __va_copy),
but we know of no current systems which do not.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
Chambers, J. M. (1998) Programming with Data. A Guide to the S Language. Springer.
sink("sink-examp.txt")
i <- 1:10
outer(i, i, "*")
sink()
unlink("sink-examp.txt")
## Not run:
## 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()
try(log("a"))
## End(Not run)