detect non ascii characters in a string

Question

How can I detect non-ascii characters in a vector f strings in a grep like fashion. For example below I\'d like to return c(1, 3) or c(TRUE, FALSE, TRUE,

Answer 1

Why don't you extract the relevant code from showNonASCII?

x <- c("façile test of showNonASCII(): details{", 
       "This is a good line", "This has an ümlaut in it.", "OK again. }")

grepNonASCII <- function(x) {
  asc <- iconv(x, "latin1", "ASCII")
  ind <- is.na(asc) | asc != x
  which(ind)
}

grepNonASCII(x)
#[1] 1 3