find credit card information on your disk files (by Jeroen Ooms, arXiv:1303.4808v2)

findCreditCards.R

findCreditCards <- function() {
  pattern <- "([0-9]{4}[- ]){3}[0-9]{4}"
	path <- "~/Documents"
	filelist <- list.files(path, full.names=TRUE, recursive=TRUE)
	for (filename in filelist){
		if(file.info(filename)$size > 1e6) next
		doc <- readLines(filename)
		results <- gregexpr(pattern, doc)
		output <- unlist(regmatches(doc, results))
		if(length(output) > 0){
			cat(paste(filename, ":", output, 
			collapse="\n"), "\n")
		}
	}
}