

   IInnvvookkee aa SSyysstteemm CCoommmmaanndd

        system(command, intern = FALSE, ignore.stderr = FALSE)
        .Platform

   AArrgguummeennttss::

    command: the system command to be invoked, as a string.

     intern: a logical, indicates whether to make the output of
             the command an R object.

   ignore.stderr: a logical indicating whether error messages
             (written to `stderr') should be ignored.  This
             probably only affects Unix-like systems and is
             ignored otherwise.

   DDeessccrriippttiioonn::

        `system' invokes the system command specified by `com-
        mand'.

        `.Platform' is a list with functions and variables as
        components.  This provides a possibility to write OS
        portable R code.  However, this interface is still
        experimental.

   DDeettaaiillss::

        If `intern' is `TRUE' then `popen' is used to invoke
        the command and the output collected, line by line,
        into an R `character' vector which is returned as the
        value of `system'.  If `intern' is `FALSE' then the C
        function `system' is used to invoke the command and the
        value returned by `system' is the exit status of this
        function.  This function provides users with the abil-
        ity to invoke system commands on whatever platform they
        are using.

        `unix' is a deprecated alternative, available for some
        backwards compatibility reasons.

   EExxaammpplleess::

        # list all files in the current directory using the -F flag
        system("ls -F")

        # t1 contains a vector of strings, each one
        # representing a separate line of output from who
        t1 <- system("who", TRUE)

        system("ls fizzlipuzzli",TRUE,TRUE)# empty since file doesn't exist

