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capabilities: Report Capabilities of this Build of R

capabilities

R Documentation

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,
             Xchk = any(nas %in% c("X11", "jpeg", "png", "tiff")))

Arguments

`what`	character vector or `NULL`, specifying required components. `NULL` implies that all are required.
`Xchk`	`logical` with a smart default, indicating if X11-related capabilities should be fully checked, notably on macOS. If set to false, may avoid a warning “No protocol specified” and e.g., the "X11" capability may be returned as `NA`.

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.

`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)?
`Rprof`	is there support for `Rprof()` profiling? This is true if R was configured (before compilation) with default settings which include `--enable-R-profiling`.
`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 `bmp`, `jpeg`, `png` and `tiff` devices? Prior to R 4.1.0 this also indicated Cairo support in the `X11` device, but it is now possible to build R with Cairo support for the bitmap devices without support for the `X11` device (usually when that is not supported at all).
`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. Since R 4.0.0 `.Machine` gives information on the long-double type (if present).
`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

capabilities()

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

## Does not call the internal X11-checking function:
capabilities(Xchk = FALSE)

## See also the examples for 'connections'.