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SETLOCALE(3)               Linux Programmer's Manual              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  implementa-
       tion-dependent.   For  glibc, first (regardless of category), the envi-
       ronment 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  set-
       locale() 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:
           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
       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
       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
       This page is part of release 3.53 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)