R: Query or Set Aspects of the Locale

locales {base} | R Documentation

## Query or Set Aspects of the Locale

### Description

Get details of or set aspects of the locale for the R process.

### Usage

    Sys.getlocale(category = "LC_ALL")
    Sys.setlocale(category = "LC_ALL", locale = "")

### Arguments

`category` | character string. The following categories should always be supported: `"LC_ALL"`, `"LC_COLLATE"`, `"LC_CTYPE"`, `"LC_MONETARY"`, `"LC_NUMERIC"` and `"LC_TIME"`. Some systems will also support `"LC_MESSAGES"`, `"LC_PAPER"` and `"LC_MEASUREMENT"`.
`locale` | character string. A valid locale name on the system in use. Normally `""` (the default) will pick up the default locale for the system.

### Details

The locale describes aspects of the internationalization of a program. Initially most aspects of the locale of R are set to `"C"` (which is the default for the C language and reflects North-American usage). R sets `"LC_CTYPE"` and `"LC_COLLATE"`, which allow the use of a different character set and alphabetic comparisons in that character set (including the use of `sort`), `"LC_MONETARY"` (for use by `Sys.localeconv`) and `"LC_TIME"` may affect the behaviour of `as.POSIXlt` and `strptime` and functions which use them (but not `date`).

R can be built with no support for locales, but it is normally available on Unix and is available on Windows.

The first seven categories described here are those specified by POSIX. `"LC_MESSAGES"` will be `"C"` on systems that do not support message translation, and is not supported on Windows. Trying to use an unsupported category is an error for `Sys.setlocale`.

Note that setting `"LC_ALL"` sets only `"LC_COLLATE"`, `"LC_CTYPE"`, `"LC_MONETARY"` and `"LC_TIME"`.

Attempts to set an invalid locale are ignored. There may or may not be a warning, depending on the OS.

Attempts to change the character set (by `Sys.setlocale("LC_TYPE", )`, if that implies a different character set) during a session may not work and are likely to lead to some confusion.

### Value

A character string of length one describing the locale in use (after setting for `Sys.setlocale`), or an empty character string if the current locale settings are invalid or `NULL` if locale information is unavailable.
For `category = "LC_ALL"` the details of the string are system-specific: it might be a single locale name or a set of locale names separated by `"/"` (Solaris, Mac OS X) or `";"` (Windows, Linux). For portability, it is best to query categories individually: it is not necessarily the case that the result of `foo <- Sys.getlocale()` can be used in `Sys.setlocale("LC_ALL", locale = foo)`.

### Warning

Setting `"LC_NUMERIC"` may cause R to function anomalously, so gives a warning. As from R 2.7.0 input conversions in R itself are unaffected, but the reading and writing of ASCII `save` files will be, as may packages. Setting it temporarily to produce graphical or text output may work well enough, but `options(OutDec)` is often preferable.

### See Also

`strptime` for uses of `category = "LC_TIME"`. `Sys.localeconv` for details of numerical and monetary representations.

`l10n_info` gives some summary facts about the locale and its encoding.

### Examples

    Sys.getlocale()
    Sys.getlocale("LC_TIME")
    ## Not run:
    Sys.setlocale("LC_TIME", "de")     # Solaris 7: details are OS-dependent
    Sys.setlocale("LC_TIME", "de_DE.utf8")  # Modern Linux etc.
    Sys.setlocale("LC_TIME", "German") # Windows
    ## End(Not run)
    Sys.getlocale("LC_PAPER")          # may or may not be set

    Sys.setlocale("LC_COLLATE", "C")   # turn off locale-specific sorting

[Package base version 2.8.1 Index]