system() and R 1.7 - R-help

Benjamin.STABLER@odot.state.or.us

Fri, Apr 18, 2003 11:04 AM #

I am using the system(command, input=a character vector) command on a
Windows NT machine and I now get the following warning with R 1.7:

Warning message: 
the condition has length > 1 and only the first element will be used in: if
(input != "") { 

I think I am getting this warning because, according to Peter Dalgaard, R
1.7 now gives a warning if if() and while() are called with a vector
condition.  Is there anyway to fix this issue besides options(warn=-1)?
Thanks.

function (command, intern = FALSE, wait = TRUE, input = "",
show.output.on.console = FALSE, 
    minimized = FALSE, invisible = FALSE) 
{
    f <- ""
    if (input != "") {
        f <- tempfile()
        on.exit(unlink(f))
        cat(input, file = f, sep = "\n")
    }
    if (intern) 
        flag <- 3
    else {
        if (wait) 
            flag <- ifelse(show.output.on.console, 2, 1)
        else flag <- 0
    }
    if (invisible) 
        flag <- 20 + flag
    else if (minimized) 
        flag <- 10 + flag
    .Internal(system(command, as.integer(flag), f))
}
<environment: namespace:base>

Benjamin Stabler
Transportation Planning Analysis Unit
Oregon Department of Transportation
555 13th Street NE, Suite 2
Salem, OR 97301  Ph: 503-986-4104

Uwe Ligges

Sat, Apr 19, 2003 4:24 AM #

Benjamin.STABLER at odot.state.or.us wrote:

The fix to system would be as follows (just those two lines):

function (command, intern = FALSE, wait = TRUE, input = NULL,

if(!is.null(input)){

Uwe Ligges

Duncan Murdoch

Sat, Apr 19, 2003 9:07 AM #

On Fri, 18 Apr 2003 11:04:48 -0700, you wrote:

This is a bug, fixed in the current patch version.  To fix your own,
you could edit the file library/base/R/base, as follows:

27878c27879
< system <- function(command, intern = FALSE, wait = TRUE, input = "",
---

27883c27884
<     if (input!="") {
---

The top lines are the released version, the lower lines are the patch.

Duncan Murdoch