This help topic is for R version 2.9.0. For the current version of R, try https://stat.ethz.ch/R-manual/R-patched/library/base/html/locales.html
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. 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.

Note

Changing the values of locale categories whilst R is running ought to be noticed by the OS services, and usually is: one known exception is collation on Mac OS X which always uses the setting from the start of the session.

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: details are OS-dependent
Sys.setlocale("LC_TIME", "de_DE.utf8")  # Modern Linux etc.
Sys.setlocale("LC_TIME", "de_DE")  # Mac OS X
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 2.9.0 ]