base (version 3.5.0)

message: Diagnostic Messages

Description

Generate a diagnostic message from its arguments.

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 message only) a single condition object.

domain

see gettext. If NA, messages will not be translated, see also the note in stop.

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

# 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())
# }