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



NAME
       setlocale - set the current locale

SYNOPSIS
       #include 

       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
       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	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
       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 3.22 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)