Nothing
##' Display the contents of a text file to the R console
##'
##' @export
##' @param file Text string giving the file name
##'
##' @param n Integer specifying the maximum number of lines to read from the file. This is passed
##' to the \code{n} argument of \code{\link{readLines}}. The default is \code{-1},
##' which will read all the lines in the file.
##'
##' @param display Text string that uniquely identifies one of \code{"all"}, \code{"head"},
##' or \code{"tail"}. Defaults to \code{"all"}, which causes all lines read from the file
##' to be displayed, \code{"head"} shows the first 6 lines that were read, and \code{"tail"} shows
##' the last 6 lines that were read.
##'
##' @return Returns nothing, but it does display the contents of the file on the R console.
##'
##' @seealso \code{\link{readLines}}
##'
##' @author Landon Sego
##'
##' @examples
##' cat("Here's a file\n", "with a few lines\n",
##' "to read.\n", sep = "", file = "tmpFile.txt")
##' more("tmpFile.txt")
##' unlink("tmpFile.txt")
more <- function(file, n = -1, display = c("all", "head", "tail")) {
# Check inputs
stopifnotMsg(# file
if (is.character(file) & (length(file) == 1)) {
file.exists(file)
} else FALSE,
"'file' must be a character string and the file must exist",
# n
if (is.numeric(n) & (length(n) == 1)) {
(n >= -1) & (n %% 1 == 0)
} else FALSE,
"'n' must be in one of -1, 0, 1, 2, ...")
if (!is.integer(n)) {
n <- as.integer(n)
}
display <- match.arg(display)
# Read the file
fileIn <- readLines(file, n = n)
# Get head or tail if requested
if (display == "head") {
fileIn <- head(fileIn)
}
else if (display == "tail") {
fileIn <- tail(fileIn)
}
# Now send file contents to the screen
cat(paste(fileIn, collapse = "\n"), "\n")
} # more
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.