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`setlocale', `localeconv'--select or query locale

     #include <locale.h>
     char *setlocale(int CATEGORY, const char *LOCALE);
     lconv *localeconv(void);
     char *_setlocale_r(void *REENT,
         int CATEGORY, const char *LOCALE);
     lconv *_localeconv_r(void *REENT);
`setlocale' is the facility defined by ANSI C to condition the
execution environment for international collating and formatting
information; `localeconv' reports on the settings of the current locale.
   This is a minimal implementation, supporting only the required
```C''' value for LOCALE; strings representing other locales are not
honored unless MB_CAPABLE is defined in which case three new extensions
are allowed for LC_CTYPE or LC_MESSAGES only: `''C-JIS''',
`''C-EUCJP''', `''C-SJIS''', or `''C-ISO-8859-1'''.  (```''' is also
accepted; it represents the default locale for an implementation, here
equivalent to ```C'''.)
   If you use `NULL' as the LOCALE argument, `setlocale' returns a
pointer to the string representing the current locale (always ```C'''
in this implementation).  The acceptable values for CATEGORY are
defined in ``locale.h'' as macros beginning with `"LC_"', but this
implementation does not check the values you pass in the CATEGORY
   `localeconv' returns a pointer to a structure (also defined in
``locale.h'') describing the locale-specific conventions currently in
   `_localeconv_r' and `_setlocale_r' are reentrant versions of
`localeconv' and `setlocale' respectively.  The extra argument REENT is
a pointer to a reentrancy structure.
`setlocale' returns either a pointer to a string naming the locale
currently in effect (always ```C''' for this implementation, or, if the
locale request cannot be honored, `NULL'.
   `localeconv' returns a pointer to a structure of type `lconv', which
describes the formatting and collating conventions in effect (in this
implementation, always those of the C locale).
ANSI C requires `setlocale', but the only locale required across all
implementations is the C locale.
   No supporting OS subroutines are required.