% File src/library/utils/man/askYesNo.Rd | |
% Part of the R package, https://www.R-project.org | |
% Copyright 2017 R Core Team | |
% Distributed under GPL 2 or later | |
\name{askYesNo} | |
\alias{askYesNo} | |
\title{ | |
Ask a Yes/No Question | |
} | |
\description{ | |
\code{askYesNo} provides a standard way to ask the user a yes/no question. | |
It provides a way for front-ends to substitute their own dialogs. | |
} | |
\usage{ | |
askYesNo(msg, default = TRUE, | |
prompts = getOption("askYesNo", gettext(c("Yes", "No", "Cancel"))), | |
...) | |
} | |
\arguments{ | |
\item{msg}{ | |
The prompt message for the user. | |
} | |
\item{default}{ | |
The default response. | |
} | |
\item{prompts}{ | |
Any of: a character vector containing 3 prompts corresponding to | |
return values of \code{TRUE}, \code{FALSE}, or \code{NA}, or | |
a single character value containing the prompts separated by | |
\code{/} characters, or a function to call. | |
} | |
\item{\dots}{ | |
Additional parameters, ignored by the default function. | |
} | |
} | |
\details{ | |
\code{askYesNo} will accept case-independent partial matches to the prompts. | |
If no response | |
is given the value of \code{default} will be returned; if a non-empty | |
string that doesn't match any of the prompts is entered, an error will be | |
raised. | |
If a function or single character string naming a function | |
is given for \code{prompts}, it will be called as | |
\code{fn(msg = msg, default = default, prompts = prompts, ...)}. On | |
Windows, the GUI uses the unexported \code{utils:::askYesNoWinDialog} | |
function for this purpose. | |
If strings (or a string such as \code{"Y/N/C"}) are given as \code{prompts}, | |
the choices will be mapped to lowercase for the non-default choices, and | |
left as-is for the default choice. | |
} | |
\value{ | |
\code{TRUE} for yes, \code{FALSE} for no, and \code{NA} for cancel. | |
} | |
\seealso{ | |
\code{readline} for more general user input. | |
} | |
\examples{ | |
if (interactive()) | |
askYesNo("Do you want to use askYesNo?") | |
} | |
\keyword{utilities} |