message
Diagnostic Messages
Generate a diagnostic message from its arguments.
- Keywords
- programming
Usage
message(…, domain = NULL, appendLF = TRUE)
suppressMessages(expr)packageStartupMessage(…, domain = NULL, appendLF = TRUE)
suppressPackageStartupMessages(expr)
.makeMessage(…, domain = NULL, appendLF = FALSE)
Arguments
- …
zero or more objects which can be coerced to character (and which are pasted together with no separator) or (for
messageonly) a single condition object.- domain
see
gettext. IfNA, messages will not be translated, see also the note instop.- appendLF
logical: should messages given as a character string have a newline appended?
- expr
expression to evaluate.
Details
message is used for generating ‘simple’ diagnostic
messages which are neither warnings nor errors, but nevertheless
represented as conditions. Unlike warnings and errors, a final
newline is regarded as part of the message, and is optional.
The default handler sends the message to the
stderr() connection.
If a condition object is supplied to message it should be
the only argument, and further arguments will be ignored, with a warning.
While the message is being processed, a muffleMessage restart
is available.
suppressMessages evaluates its expression in a context that
ignores all ‘simple’ diagnostic messages.
packageStartupMessage is a variant whose messages can be
suppressed separately by suppressPackageStartupMessages. (They
are still messages, so can be suppressed by suppressMessages.)
.makeMessage is a utility used by message, warning
and stop to generate a text message from the …
arguments by possible translation (see gettext) and
concatenation (with no separator).
See Also
warning and stop for generating warnings
and errors; conditions for condition handling and
recovery.
gettext for the mechanisms for the automated translation
of text.
Examples
library(base)
# NOT RUN {
message("ABC", "DEF")
suppressMessages(message("ABC"))
testit <- function() {
message("testing package startup messages")
packageStartupMessage("initializing ...", appendLF = FALSE)
Sys.sleep(1)
packageStartupMessage(" done")
}
testit()
suppressPackageStartupMessages(testit())
suppressMessages(testit())
# }