Check readline input — readline_check • faux

Check readline input

readline_check(
  prompt,
  type = c("numeric", "integer", "length", "grep"),
  min = -Inf,
  max = Inf,
  warning = NULL,
  default = NULL,
  ...
)

Arguments

prompt: the prompt for readline
type: what type of check to perform, one of c("numeric", "integer", "length", "grep")
min: the minimum value
max: the maximum value
warning: an optional custom warning message
default: the default option to return if the entry is blank, NULL allows no default, the default value will be displayed after the text as [default]
...: other arguments to pass to grep

Value

the validated result of readline

Examples

if(interactive()){
readline_check("Type a number: ", "numeric")
readline_check("Type two characters: ", "length", min = 2, max = 2)
readline_check("Type at least 3 characters: ", "length", min = 3)
readline_check("Type no more than 4 characters: ", "length", max = 44)
readline_check("Type a letter and a number: ", "grep", pattern = "^[a-zA-Z]\\d$")
}