setlocale (3)

NAME

       setlocale - set the current locale.

SYNOPSIS

       #include <locale.h>

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

DESCRIPTION

       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 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.

       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,  con-
              version,  case-sensitive  comparison,  and  wide character func-
              tions.

       LC_MESSAGES
              for localizable natural-language messages.

       LC_MONETARY
              for monetary formatting.

       LC_NUMERIC
              for number formatting (such as the decimal point and  the  thou-
              sands 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_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.

       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.

RETURN VALUE

       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-
       ored.

CONFORMING TO

       ANSI C, POSIX.1

NOTES

       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.

SEE ALSO

       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)