NAME

setlocale — natural language formatting for C

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <locale.h>

char *
setlocale(int category, const char *locale);

DESCRIPTION

The setlocale() function sets the C library's notion of natural language formatting style for particular sets of routines. Each such style is called a ‘locale’ and is invoked using an appropriate name passed as a C string.

The setlocale() function recognizes several categories of routines. These are the categories and the sets of routines they select:

LC_ALL

Set the entire locale generically.

LC_COLLATE

Set a locale for string collation routines. This controls alphabetic ordering in strcoll() and strxfrm().

LC_CTYPE

Set a locale for the ctype(3) and multibyte(3) functions. This controls recognition of upper and lower case, alphabetic or non-alphabetic characters, and so on.

LC_MESSAGES

Set a locale for message catalogs, see catopen(3) function.

LC_MONETARY

Set a locale for formatting monetary values; this affects the localeconv() function.

LC_NUMERIC

Set a locale for formatting numbers. This controls the formatting of decimal points in input and output of floating point numbers in functions such as printf() and scanf(), as well as values returned by localeconv().

LC_TIME

Set a locale for formatting dates and times using the strftime() function.

Only three locales are defined by default: the empty string "" (which denotes the native environment) and the "C" and "POSIX" locales (which denote the C language environment). A locale argument of NULL causes setlocale() to return the current locale. An argument of "" will determine the name of the new locale taking into account the environment variables LANG and LC_*. If these environment variables yield a locale that is invalid, NULL will be returned and the current locale will remain unchanged. By default, C programs start in the "C" locale. The only function in the library that sets the locale is setlocale(); the locale is never changed as a side effect of some other routine.

RETURN VALUES

Upon successful completion, setlocale() returns the string associated with the specified category for the requested locale. The setlocale() function returns NULL and fails to change the locale if the given combination of category and locale makes no sense.

FILES

$PATH_LOCALE/locale/category

 

/usr/share/locale/locale/category

locale file for the locale locale and the category category.

/usr/local/share/locale/locale/category

locale file for the locale locale and the category category.

ERRORS

No errors are defined.

SEE ALSO

colldef(1), mklocale(1), catopen(3), ctype(3), localeconv(3), multibyte(3), strcoll(3), strxfrm(3), euc(5), utf8(5), environ(7)

STANDARDS

The setlocale() function conforms to ISO/IEC 9899:1999 (“ISO C99”).

HISTORY

The setlocale() function first appeared in 4.4BSD.