R: Read R Code from a File or a Connection

source {base}

R Documentation

Read R Code from a File or a Connection

Description

source causes R to accept its input from the named file (the name must be quoted). Input is read from that file until the end of the file is reached. parse is used to scan the expressions in, they are then evaluated sequentially in the chosen environment.

Usage

source(file, local = FALSE, echo = verbose, print.eval = echo,
       verbose = getOption("verbose"),  prompt.echo = getOption("prompt"),
       max.deparse.length = 150, chdir = FALSE)

Arguments

`file`	a connection or a character string giving the name of the file or URL to read from.
`local`	if `local` is `FALSE`, the statements scanned are evaluated in the user's workspace (the global environment), otherwise in the environment calling `source`.
`echo`	logical; if `TRUE`, each expression is printed after parsing, before evaluation.
`print.eval`	logical; if `TRUE`, the result of `eval(i)` is printed for each expression `i`; defaults to `echo`.
`verbose`	if `TRUE`, more diagnostics (than just `echo = TRUE`) are printed during parsing and evaluation of input, including extra info for each expression.
`prompt.echo`	character; gives the prompt to be used if `echo = TRUE`.
`max.deparse.length`	integer; is used only if `echo` is `TRUE` and gives the maximal length of the “echo” of a single expression.
`chdir`	logical; if `TRUE`, the R working directory is changed to the directory containing `file` for evaluating.

Details

All versions of R accept input from a connection with end of line marked by LF (as used on Unix), CRLF (as used on DOS/Windows) or CR (as used on classic MacOS). The final line can be incomplete, that is missing the final EOL marker.

If options("keep.source") is true (the default), the source of functions is kept so they can be listed exactly as input. This imposes a limit of 128K chars on the function size and a nesting limit of 265. Use option(keep.source = FALSE) when these limits might take effect: if exceeded they generate an error.

References