Is R Running Interactively?
TRUE when R is being used interactively and
An interactive R session is one in which it is assumed that there is
a human operator to interact with, so for example R can prompt for
corrections to incorrect input or ask what to do next or if it is OK
to move to the next plot. GUI consoles will arrange to start R in an interactive session. When
R is run in a terminal (via
Rterm.exe on Windows), it
assumes that it is interactive if
stdin is connected to a
(pseudo-)terminal and not if
stdin is redirected to a file or
pipe. Command-line options --interactive (Unix) and
Rterm.exe) override the default
(On a Unix-alike, whether the
readline command-line editor is
used is not overridden by --interactive.) Embedded uses of R can set a session to be interactive or not. Internally, whether a session is interactive determines
- how some errors are handled and reported, e.g. see
- whether one of --save, --no-save or --vanilla is required, and if R ever asks whether to save the workspace.
- the choice of default graphics device launched when needed and
- whether graphics devices ever ask for confirmation of a new page.
interactive(): for example
This is a primitive function.
.First <- function() if(interactive()) x11()