NAME
setlocale —
natural language formatting for
C
LIBRARY
library “libc”
SYNOPSIS
#include
<locale.h>
char *
setlocale(int
category, const char
*locale);
DESCRIPTION
Thesetlocale()
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() andstrxfrm(). 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() andscanf(), as well as values returned bylocaleconv(). LC_TIME- Set a locale for formatting dates and times using the
strftime() function. LANG- Sets the generic locale category for native language, local customs and coded character set in the absence of more specific locale variables.
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.
The option -a to the
locale(1) command can be used to display all further possible names
for the locale argument that are recognized.
Specifying any unrecognized value for locale makes
setlocale()
fail.
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.
EXAMPLES
The following code illustrates how a program can initialize the international environment for one language, while selectively modifying the program's locale such that regular expressions and string operations can be applied to text recorded in a different language:
setlocale(LC_ALL, "de");
setlocale(LC_COLLATE, "fr");
When a process is started, its current locale is set to the C or POSIX locale. An internationalized program that depends on locale data not defined in the C or POSIX locale must invoke the setlocale subroutine in the following manner before using any of the locale-specific information:
setlocale(LC_ALL, "");
ERRORS
No errors are defined.
SEE ALSO
locale(1), localedef(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.