toscutil (version 2.8.0)

logf: logf function

Description

Prints a formatted string with optional prefix and end string. The default prefix is a grey timestamp and the default end is a newline character, which is useful for logging messages. All defaults can be set globally using options(). For details see 'Examples'.

Usage

logf(
  fmt,
  ...,
  file = .Options$toscutil.logf.file %||% "",
  append = .Options$toscutil.logf.append %||% FALSE,
  prefix = .Options$toscutil.logf.prefix %||% function() now_ms(usetz = FALSE, color =
    fg$GREY),
  sep1 = .Options$toscutil.logf.sep1 %||% " ",
  sep2 = .Options$toscutil.logf.sep2 %||% "",
  end = .Options$toscutil.logf.end %||% "\n"
)

Value

No return value. This function is called for its side effect of printing a message.

Arguments

...

Arguments to be passed to sprintf for string formatting.

file

A file() connection object or a string naming the file to print to. If "" (the default), output is printed to STDOUT unless redirected by sink().

append

Logical. If TRUE, the output is appended to the file. If FALSE, the file is overwritten.

prefix

A function returning a string to be used as the prefix.

sep1

A string to be used as the separator between the prefix and the formatted string.

sep2

A string to be used as the separator between the formatted string and the end.

end

A string to be used as the end of the message.

Examples

logf("Hello, %s!", "world")
logf("Goodbye", prefix = function() "", sep1 = "", end = "!\n")
local({
     opts <- options(toscutil.logf.prefix = function() "LOG:", toscutil.logf.end = "\n")
     on.exit(options(opts))
     logf("Hello, %s!", "world")
})