capabilities: Report Capabilities of this Build of R

Description

Report on the optional features which have been compiled into this build of R.

Usage

capabilities(what = NULL)

Arguments

what

character vector or NULL, specifying required components. NULL implies that all are required.

Value

A named logical vector. Current components are

jpeg

is the jpeg function operational?

png

is the png function operational?

tiff

is the tiff function operational?

tcltk

is the tcltk package operational? Note that to make use of Tk you will almost always need to check that "X11" is also available.

X11

are the X11 graphics device and the X11-based data editor available? This loads the X11 module if not already loaded, and checks that the default display can be contacted unless a X11 device has already been used.

aqua

is the quartz function operational? Only on some macOS builds, including CRAN binary distributions of R.

Note that this is distinct from .Platform$GUI == "AQUA", which is true only when using the Mac R.app GUI console.

X11

always FALSE on Windows.

aqua

FALSE except on macOS.

http/ftp

does the internal method for url and download.file support http:// and ftp:// URLs? Always TRUE as from R 3.3.0.

sockets

are make.socket and related functions available? Always TRUE as from R 3.3.0.

libxml

is there support for integrating libxml with the R event loop? Always TRUE as from R 3.3.0.

fifo

are FIFO connections supported?

cledit

is command-line editing available in the current R session? This is false in non-interactive sessions. It will be true for the command-line interface if readline support has been compiled in and --no-readline was not used when R was invoked. (If --interactive was used, command-line editing will not actually be available.)

iconv

is internationalization conversion via iconv supported? Always true in current R.

NLS

is there Natural Language Support (for message translations)?

profmem

is there support for memory profiling? See tracemem.

cairo

is there support for the svg, cairo_pdf and cairo_ps devices, and for type = "cairo" in the X11, bmp, jpeg, png, and tiff devices?

ICU

is ICU available for collation? See the help on Comparison and icuSetCollate: it is never used for a C locale.

long.double

does this build use a C long double type which is longer than double? Some platforms do not have such a type, and on others its use can be suppressed by the configure option --disable-long-double.

Although not guaranteed, it is a reasonable assumption that if present long doubles will have at least as much range and accuracy as the ISO/IEC 60559 80-bit ‘extended precision’ format.

libcurl

is libcurl available in this build? Used by function curlGetHeaders and optionally by download.file and url. As from R 3.3.0 always true for Unix-alikes, and true for CRAN Windows builds.

Note to macOS users

Capabilities "jpeg", "png" and "tiff" refer to the X11-based versions of these devices. If capabilities("aqua") is true, then these devices with type = "quartz" will be available, and out-of-the-box will be the default type. Thus for example the tiff device will be available if capabilities("aqua") || capabilities("tiff") if the defaults are unchanged.

Examples

Run this code

# NOT RUN {
capabilities()

if(!capabilities("ICU"))
   warning("ICU is not available")

## See also the examples for 'connections'.
# }