cat                   package:base                   R Documentation

Concatenate and Print

Description:

     Prints the arguments, coercing them if necessary to character mode
     first.

Usage:

     cat(... , file = "", sep = " ", fill = FALSE, labels = NULL,
         append = FALSE)

Arguments:

     ...: R objects which are coerced to character strings,
          concatenated, and printed, with the remaining arguments
          controlling the output.

    file: A connection, or a character string naming the file to print
          to.  If `""' (the default), `cat' prints to the standard
          output connection, the console unless redirected by `sink'.
          If it is `"|cmd"', the output is piped to the command given
          by `cmd', by opening a pipe connection. 

     sep: character string to insert between the objects to print.

    fill: a logical or numeric controlling how the output is broken
          into successive lines.  If `FALSE' (default), only newlines
          created explicitly by `\n' are printed.  Otherwise, the
          output is broken into lines with print width equal to the
          option `width' if `fill' is `TRUE', or the value of `fill' if
          this is numeric.

  labels: character vector of labels for the lines printed. Ignored if
          `fill' is `FALSE'.

  append: logical. Only used if the argument `file' is the name of file
          (and not a connection or `"|cmd"'). If `TRUE' output will be
          appended to `file'; otherwise, it will overwrite the contents
          of `file'.

Details:

     `cat' converts its arguments to character strings, concatenates
     them, separating them by the given `sep=' string, and then prints
     them.

     No linefeeds are printed unless explicitly requested by `"\n"' or
     if generated by filling (if argument `fill' is `TRUE' or numeric.)

     `cat' is useful for producing output in user-defined functions.

Value:

     None (invisible `NULL').

See Also:

     `print', `format', and `paste' which concatenates into a string.

Examples:

     ## print an informative message
     cat("iteration = ", iter <- iter + 1, "\n")

     ## `fill' and label lines:
     cat(paste(letters, 100* 1:26), fill = TRUE,
         labels = paste("{",1:10,"}:",sep=""))

