setlocale

lucid  ( 3 )  setlocale.3.gz
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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
       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
       multi-byte  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

       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

       C89, C99, POSIX.1-2001.

NOTES

       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

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

COLOPHON

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       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.