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

       setlocale - set the current locale.

       #include <locale.h>

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

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

       If locale is not NULL, the program's current locale is modified accord-
       ing  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.

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

              for regular expression matching, character classification,  con-
              version,  case-sensitive  comparison,  and  wide character func-

              for localizable natural-language messages.

              for monetary formatting.

              for number formatting (such as the decimal point and  the  thou-
              sands separator).

              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_MONE-
       TARY,  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  cor-
       responds to the 7-bit ASCII character set.

       A  locale  name  is  typically  of the form language[_territory][.code-
       set][@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 set-
       locale(LC_ALL,  "" ) after program  initialization, by using the values
       returned from a localeconv() call for locale -  dependent  information,
       by  using the multi-byte and wide character functions for text process-
       ing if MB_CUR_MAX > 1, and by using strcoll(), wcscoll() or  strxfrm(),
       wcsxfrm() to compare strings.

       A  successful  call to setlocale() returns an opaque string that corre-
       sponds to the locale set.  This string may be allocated in static stor-
       age.   The  string  returned  is  such that a subsequent call with that
       string and its associated category will restore that part of  the  pro-
       cess's  locale.  The return value is NULL if the request cannot be hon-

       ANSI C, POSIX.1

       Linux (that is,  GNU  libc)  supports  the  portable  locales  "C"  and
       "POSIX".   In  the good old days there used to be support for the Euro-
       pean 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() return the right answer.
       These days non-English speaking Europeans have to work  a  bit  harder,
       and must install actual locale files.

       locale(1),  localedef(1),  strcoll(3), isalpha(3), localeconv(3), strf-
       time(3), charsets(4), locale(7), nl_langinfo(3)

GNU                               1999-07-04                      SETLOCALE(3)