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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | NOTES | SEE ALSO | COLOPHONThe Linux Programming Interface

SETLOCALE(3)              Linux Programmer's Manual             SETLOCALE(3)

NAME         top

       setlocale - set the current locale

SYNOPSIS         top

       #include <locale.h>

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

DESCRIPTION         top

       The setlocale() function is used to set or query the program's
       current locale.

       If locale is not NULL, the program's current locale is modified
       according to the arguments.  The argument category determines which
       parts of the program's current locale should be modified.

       LC_ALL for all of the locale.

       LC_COLLATE
              for regular expression matching (it determines the meaning of
              range expressions and equivalence classes) and string
              collation.

       LC_CTYPE
              for regular expression matching, character classification,
              conversion, case-sensitive comparison, and wide character
              functions.

       LC_MESSAGES
              for localizable natural-language messages.

       LC_MONETARY
              for monetary formatting.

       LC_NUMERIC
              for number formatting (such as the decimal point and the
              thousands separator).

       LC_TIME
              for time and date formatting.

       The argument locale is a pointer to a character string containing the
       required setting of category.  Such a string is either a well-known
       constant like "C" or "da_DK" (see below), or an opaque string that
       was returned by another call of setlocale().

       If locale is "", each part of the locale that should be modified is
       set according to the environment variables.  The details are
       implementation-dependent.  For glibc, first (regardless of category),
       the environment variable LC_ALL is inspected, next the environment
       variable with the same name as the category (LC_COLLATE, LC_CTYPE,
       LC_MESSAGES, LC_MONETARY, LC_NUMERIC, LC_TIME) and finally the
       environment variable LANG.  The first existing environment variable
       is used.  If its value is not a valid locale specification, the
       locale is unchanged, and setlocale() returns NULL.

       The locale "C" or "POSIX" is a portable locale; its LC_CTYPE part
       corresponds to the 7-bit ASCII character set.

       A locale name is typically of the form
       language[_territory][.codeset][@modifier], where language is an ISO
       639 language code, territory is an ISO 3166 country code, and codeset
       is a character set or encoding identifier like ISO-8859-1 or UTF-8.
       For a list of all supported locales, try "locale -a", cf. locale(1).

       If locale is NULL, the current locale is only queried, not modified.

       On startup of the main program, the portable "C" locale is selected
       as default.  A program may be made portable to all locales by
       calling:

           setlocale(LC_ALL, "");

       after program initialization, by using the values returned from a
       localeconv(3) call for locale-dependent information, by using the
       multibyte and wide character functions for text processing if
       MB_CUR_MAX > 1, and by using strcoll(3), wcscoll(3) or strxfrm(3),
       wcsxfrm(3) to compare strings.

RETURN VALUE         top

       A successful call to setlocale() returns an opaque string that
       corresponds to the locale set.  This string may be allocated in
       static storage.  The string returned is such that a subsequent call
       with that string and its associated category will restore that part
       of the process's locale.  The return value is NULL if the request
       cannot be honored.

CONFORMING TO         top

       C89, C99, POSIX.1-2001.

NOTES         top

       Linux (that is, glibc) supports the portable locales "C" and "POSIX".
       In the good old days there used to be support for the European
       Latin-1 "ISO-8859-1" locale (e.g., in libc-4.5.21 and libc-4.6.27),
       and the Russian "KOI-8" (more precisely, "koi-8r") locale (e.g., in
       libc-4.6.27), so that having an environment variable
       LC_CTYPE=ISO-8859-1 sufficed to make isprint(3) return the right
       answer.  These days non-English speaking Europeans have to work a bit
       harder, and must install actual locale files.

SEE ALSO         top

       locale(1), localedef(1), isalpha(3), localeconv(3), nl_langinfo(3),
       rpmatch(3), strcoll(3), strftime(3), charsets(7), locale(7)

COLOPHON         top

       This page is part of release 3.51 of the Linux man-pages project.  A
       description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU                              2008-12-05                     SETLOCALE(3)

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