









	   X11R6 Sample Implementation Frame Work



		       Katsuhisa Yano
		    TOSHIBA Corporation

		      Yoshio Horiuchi
			 IBM Japan






































































Copyright (C) 1994 by TOSHIBA Corporation
Copyright (C) 1994 by IBM Corporation

Permission to use, copy, modify, and distribute this docu-
mentation for any purpose and without fee is hereby granted,
provided that the above copyright notice and this permission
notice appear in all copies.  TOSHIBA Corporation and IBM
Corporation make no representations about the suitability
for any purpose of the information in this document.  This
documentation is provided as is without express or implied
warranty.





Copyright (C) 1994 X Consortium

Permission is hereby granted, free of charge, to any person
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The above copyright notice and this permission notice shall
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1.  Preface

This document proposes to define the structures, methods and
their signatures that are expected to be common to all
locale dependent functions within the Xlib sample implemen-
tation.  The following illustration (Fig.1) is proposed to
outline the separating of the components within the sample
implementation.

    ... 0.237 5.796 5.24 10.14 ... 0.000i 4.344i 5.003i
    0.000i

	      ___________________________________|
	      _____________Application___________|
		  |	    |	    |	      |
		  |	    |	   ||	     ||
		  |	    |	   ||	     ||
       <<  ANSI/MSE API <<  XLib API  >>  <<  ANSI/MSE API >>
	 (X Contrib)	    (X Core)	    (X Contrib)
       _______________	_______________   _______________
       |Locale Library| | Input |Output|  |C Library	 |
       |   non-AnSI impl. Method|Method|  |	 ANSI impl.
       _______________| ________|______|  _______________|
	   |		| <Locl. Serv. API>	     |
	   |		|  X Locale Object	     |
	   |		_______________|	     |
	   |			|		     |
	   |	  ___________	| ___________	     |
	   |	  |		|	      |      |
       ____|______|___	________|______   ____|______|___
       |  ||	  |   | |	|      |  |  ||      |	 |
       |XLC_XLOCALE   | | XLC_FONTSET  |  |localedef DB  |
       |- MB_CUR_MAX  | | - fonset info|  |- MB_CUR_MAX  |
       |- codeset info| | - charset inf|  |- codeset info|
       |o char/charset| | - font/charse|  |o char/charset|
       _______________| _______________|  _______________|

	______________________________	   ____________
	    XLocale Source (X Core)    System LOcale Source


     Fig.1 : Frame Work of Locale Service API Proposal

Generally speaking, the internationalized portion of Xlib
(Locale Dependent X, LDX) consists of three objects; locale
(LC) , input method (IM) and output method (OM).  The LC
provides a set of information that depends on user's lan-
guage environment.  The IM manages text inputing, and the OM
manages text drawing.  Both IM and OM highly depend on LC
data.

In X11R5, there are two sample implementations, Ximp and
Xsi, for Xlib internationalization.  But in both implementa-
tions, IM and OM actually refer the private extension of LC.



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Sample Implementation Frame Work	    X11, Release 6.4


It breaks coexistence of these two sample implementations.
For example, if a user creates a new OM for special purpose
as a part of Ximp, it will not work with Xsi.

As a solution of this problem, we propose to define the
standard APIs between these three objects, and define the
structure that are common to these objects.


2.  Objective


o    Explain the current X11R6 sample implementation

o    Document the common set of locale dependent interfaces

o    Provide more flexible pluggable layer


3.  Locale Object Binding Functions

This chapter describes functions related locale object bind-
ing for implementing the pluggable layer.

A locale loader is an entry point for locale object, which
instantiates XLCd object and binds locale methods with spec-
ified locale name. The behavior of loader is implementation
dependent.  And, what kind of loaders are available is also
implementation dependent.

The loader is called in _XOpenLC, but caller of _XOpenLC
does not need to care about its inside.  For example, if the
loader is implemented with dynamic load functions, and the
dynamic module is expected to be unloaded when the corre-
sponding XLCd is freed, close methods of XLCdMethods should
handle unloading.


Initializing a locale loader list


void _XlcInitLoader()

The _XlcInitLoader function initializes the locale loader
list with vendor specific manner.  Each loader is registered
with calling _XlcAddLoader. The number of loaders and their
order in the loader list is implementation dependent.


Add a loader


typedef XLCd (*XLCdLoadProc)(name);
      char *name;



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typedef int XlcPosition;


#define   XlcHead		  0
#define   XlcTail		 -1



Bool _XlcAddLoader(proc, position)
      XLCdLoadProc proc;
      XlcPosition position;


The _XlcAddLoader function registers the specified locale
loader ``proc'' to the internal loader list.  The position
specifies that the loader ``proc'' should be placed in the
top of the loader list(XlcHead) or last(XlcTail).

The object loader is called from the top of the loader list
in order, when calling time.


Remove a loader


void _XlcRemoveLoader(proc)
      XLCdLoadProc proc;


The _XlcRemoveLoader function removes the locale loader
specified by ``proc'' from the loader list.

Current implementation provides following locale loaders;

     _XlcDefaultLoader
     _XlcGenericLoader
     _XlcEucLoader
     _XlcSjisLoader
     _XlcUtfLoader
     _XaixOsDynamicLoad



4.  Locale Method Interface

This chapter describes the locale method API, which is a set
of accessible functions from both IM and OM parts.  The
locale method API provides the functionalities;  obtaining
locale dependent information, handling charset, converting
text, etc.

As a result of using these APIs instead of accessing vender
private extension of the locale object, we can keep locale,
IM and OM independently each other.



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Sample Implementation Frame Work	    X11, Release 6.4


5.  Locale Method Functions

Open a Locale Method


XLCd _XOpenLC(name)
      char *name;


The _XOpenLC function opens a locale method which corre-
sponds to the specified locale name.  _XOpenLC calls a
locale object loader, which is registered via
_XlcAddLoaderinto is valid and successfully opens a locale,
_XOpenLC returns the XLCd.  If the loader is invalid or
failed to open a locale, _XOpenLC calls the next loader.  If
all registered loaders cannot open a locale, _XOpenLC
returns NULL.


XLCd _XlcCurrentLC()


The _XlcCurrentLC function returns an XLCd that are bound to
current locale.


Close a Locale Method


void _XCloseLC(lcd)
      XLCd lcd;


The _XCloseLC function close a locale method the specified
lcd.


Obtain Locale Method values


char * _XGetLCValues(lcd, ...)
      XLCd lcd;


The _XGetLCValues function returns NULL if no error
occurred; otherwise, it returns the name of the first argu-
ment that could not be obtained.  The following values are
defined as standard arguments. Other values are implementa-
tion dependent.








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Sample Implementation Frame Work	    X11, Release 6.4


------------------------------------------------------------------------
Name			     Type    Description
------------------------------------------------------------------------
XlcNCodeset		     char*   codeset part of locale name
XlcNDefaultString	     char*   XDefaultString()
XlcNEncodingName	     char*   encoding name
XlcNLanguage		     char*   language part of locale name
XlcNMbCurMax		     int     ANSI C MB_CUR_MAX
XlcNStateDependentEncoding   Bool    is state-dependent encoding or not
XlcNTerritory		     char*   territory part of locale name
------------------------------------------------------------------------



6.  Charset functions

The XlcCharSet is an identifier which represents a subset of
characters (character set) in the locale object.


typedef enum {
      XlcUnknown, XlcC0, XlcGL, XlcC1, XlcGR, XlcGLGR, XlcOther
} XlcSide;

typedef struct _XlcCharSetRec *XlcCharSet;

typedef struct {
      char *name;
      XPointer value;
} XlcArg, *XlcArgList;

typedef char* (*XlcGetCSValuesProc)(charset, args, num_args);
      XlcCharSet charset;
      XlcArgList args;
      int num_args;

typedef struct _XlcCharSetRec {
      char *name;
      XrmQuark xrm_name;
      char *encoding_name;
      XrmQuark xrm_encoding_name;
      XlcSide side;
      int char_size;
      int set_size;
      char *ct_sequence;
      XlcGetCSValuesProc get_values;
} XlcCharSetRec;



Get an XlcCharSet






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Sample Implementation Frame Work	    X11, Release 6.4


XlcCharSet _XlcGetCharSet(name)
      char *name;


The _XlcGetCharSet function gets an XlcCharSet which corre-
sponds to the charset name specified by ``name''.
_XlcGetCharSet returns NULL, if no XlcCharSet bound to spec-
ified ``name''.

The following character sets are pre-registered.


-----------------------------------------------------------------------
Name		     Description
-----------------------------------------------------------------------
ISO8859-1:GL	     7-bit ASCII graphics (ANSI X3.4-1968),
		     Left half of ISO 8859 sets
JISX0201.1976-0:GL   Left half of JIS X0201-1976 (reaffirmed 1984),
		     8-Bit Alphanumeric-Katakana Code

ISO8859-1:GR	     Right half of ISO 8859-1, Latin alphabet No. 1
ISO8859-2:GR	     Right half of ISO 8859-2, Latin alphabet No. 2
ISO8859-3:GR	     Right half of ISO 8859-3, Latin alphabet No. 3
ISO8859-4:GR	     Right half of ISO 8859-4, Latin alphabet No. 4
ISO8859-7:GR	     Right half of ISO 8859-7, Latin/Greek alphabet
ISO8859-6:GR	     Right half of ISO 8859-6, Latin/Arabic alphabet
ISO8859-8:GR	     Right half of ISO 8859-8, Latin/Hebrew alphabet
ISO8859-5:GR	     Right half of ISO 8859-5, Latin/Cyrillic alphabet
ISO8859-9:GR	     Right half of ISO 8859-9, Latin alphabet No. 5
JISX0201.1976-0:GR   Right half of JIS X0201-1976 (reaffirmed 1984),
		     8-Bit Alphanumeric-Katakana Code

GB2312.1980-0:GL     GB2312-1980, China (PRC) Hanzi defined as GL
GB2312.1980-0:GR     GB2312-1980, China (PRC) Hanzi defined as GR
JISX0208.1983-0:GL   JIS X0208-1983, Japanese Graphic Character Set
		     defined as GL
JISX0208.1983-0:GR   JIS X0208-1983, Japanese Graphic Character Set
		     defined as GR
KSC5601.1987-0:GL    KS C5601-1987, Korean Graphic Character Set
		     defined as GL
KSC5601.1987-0:GR    KS C5601-1987, Korean Graphic Character Set
		     defined as GR
JISX0212.1990-0:GL   JIS X0212-1990, Japanese Graphic Character Set
		     defined as GL
JISX0212.1990-0:GR   JIS X0212-1990, Japanese Graphic Character Set
		     defined as GR
-----------------------------------------------------------------------



Add an XlcCharSet






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Sample Implementation Frame Work	    X11, Release 6.4


Bool _XlcAddCharSet(charset)
      XlcCharSet charset;


The _XlcAddCharSet function registers XlcCharSet specified
by ``charset''.


Obtain Character Set values


char * _XlcGetCSValues(charset, ...)
      XlcCharSet charset;


The _XlcGetCSValues function returns NULL if no error
occurred; otherwise, it returns the name of the first argu-
ment that could not be obtained.  The following values are
defined as standard arguments.	Other values are implementa-
tion dependent.


-------------------------------------------------------------------
Name		      Type	Description
-------------------------------------------------------------------
XlcNName	      char*	charset name
XlcNEncodingName      char*	XLFD CharSet Registry and Encoding
XlcNSide	      XlcSide	charset side (GL, GR, ...)
XlcNCharSize	      int	number of octets per character
XlcNSetSize	      int	number of character sets
XlcNControlSequence   char*	control sequence of Compound Text
-------------------------------------------------------------------



7.  Converter Functions

We provide a set of the common converter APIs, that are
independent from both of source and destination text type.


typedef struct _XlcConvRec *XlcConv;

typedef void (*XlcCloseConverterProc)(conv);
      XlcConv conv;

typedef int (*XlcConvertProc)(conv, from, from_left, to, to_left, args, num_args);
      XlcConv conv;
      XPointer *from;
      int *from_left;
      XPointer *to;
      int *to_left;
      XPointer *args;
      int num_args;



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Sample Implementation Frame Work	    X11, Release 6.4


typedef void (*XlcResetConverterProc)(conv);
      XlcConv conv;

typedef struct _XlcConvMethodsRec {
      XlcCloseConverterProc close;
      XlcConvertProc convert;
      XlcResetConverterProc reset;
} XlcConvMethodsRec, *XlcConvMethods;

typedef struct _XlcConvRec {
    XlcConvMethods methods;
    XPointer state;
} XlcConvRec;



Open a converter


XlcConv _XlcOpenConverter(from_lcd, from_type, to_lcd, to_type)
      XLCd from_lcd;
      char *from_type;
      XLCd to_lcd;
      char *to_type;


_XlcOpenConverter function opens the converter which con-
verts a text from specified ``from_type'' to specified
``to_type'' encoding.  If the function cannot find proper
converter or cannot open a corresponding converter, it
returns NULL.  Otherwise, it returns the conversion descrip-
tor.

The following types are pre-defined. Other types are imple-
mentation dependent.


-----------------------------------------------------------
Name		   Type        Description	Arguments
-----------------------------------------------------------
XlcNMultiByte	   char *      multibyte	-
XlcNWideChar	   wchar_t *   wide character	-
XlcNCompoundText   char *      COMPOUND_TEXT	-
XlcNString	   char *      STRING		-
XlcNCharSet	   char *      per charset	XlcCharSet
XlcNChar	   char *      per character	XlcCharSet
-----------------------------------------------------------



Close a converter






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Sample Implementation Frame Work	    X11, Release 6.4


void _XlcCloseConverter(conv)
      XlcConv conv;


The _XlcCloseConverter function closes the specified con-
verter ``conv''.


Code conversion


int _XlcConvert(conv, from, from_left, to, to_left, args, num_args)
      XlcConv conv;
      XPointer *from;
      int *from_left;
      XPointer *to;
      int *to_left;
      XPointer *args;
      int num_args;


The _XlcConvert function converts a sequence of characters
from one type, in the array specified by ``from'', into a
sequence of corresponding characters in another type, in the
array specified by ``to''.  The types are those specified in
the _XlcOpenConverter() call that returned the conversion
descriptor, ``conv''.  The arguments ``from'',
``from_left'', ``to'' and ``to_left'' have the same specifi-
cation of XPG4 iconv function.

For state-dependent encodings, the conversion descriptor
``conv'' is placed into its initial shift state by a call
for which ``from'' is a NULL pointer, or for which ``from''
points to a null pointer.

The following 2 converters prepared by locale returns appro-
priate charset (XlcCharSet) in an area pointed by args[0].


---------------------------------------------------------
From		To	      Description
---------------------------------------------------------
XlcNMultiByte	XlcNCharSet   Segmentation (Decomposing)
XlcNWideChar	XlcNCharSet   Segmentation (Decomposing)
---------------------------------------------------------


The conversion, from XlcNMultiByte/XlcNWideChar to XlcN-
CharSet, extracts a segment which has same charset encoding
characters.  More than one segment cannot be converted in a
call.


Reset a converter



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Sample Implementation Frame Work	    X11, Release 6.4


void _XlcResetConverter(conv)
      XlcConv conv;


The _XlcResetConverter function reset the specified con-
verter ``conv''.


Register a converter


typedef XlcConv (*XlcOpenConverterProc)(from_lcd, from_type, to_lcd, to_type);
      XLCd from_lcd;
      char *from_type;
      XLCd to_lcd;
      char *to_type;



Bool _XlcSetConverter(from_lcd, from, to_lcd, to, converter)
      XLCd from_lcd;
      char *from;
      XLCd to_lcd;
      char *to;
      XlcOpenConverterProc converter;


The XlcSetConverter function registers a converter which
convert from ``from_type'' to ``to_type'' into the converter
list (in the specified XLCd).


8.  X Locale Database functions

X Locale Database contains the subset of user's environment
that depends on language.  The following APIs are provided
for accessing X Locale Database and other locale relative
files.

For more detail about  X Locale Database, please refer X
Locale Database Definition document.


Get a resource from database


void _XlcGetResource(lcd, category, class, value, count)
      XLCd lcd;
      char *category;
      char *class;
      char ***value;
      int *count;





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Sample Implementation Frame Work	    X11, Release 6.4


The _XlcGetResource function obtains a locale dependent data
which is associated with the locale of specified ``lcd''.
The locale data is provided by system locale or by X Locale
Database file, and what kind of data is available is imple-
mentation dependent.

The specified ``category'' and ``class'' are used for find-
ing out the objective locale data.

The returned  value is returned in value argument in string
list form, and the returned count shows the number of
strings in the value.

The returned value is owned by locale method, and should not
be modified or freed by caller.


Get a locale relative file name


char * _XlcFileName(lcd, category)
      XLCd lcd;
      char *category;


The _XlcFileName functions returns a file name which is
bound to the specified ``lcd'' and ``category'', as a null-
terminated string.  If no file name can be found, or there
is no readable file for the found file name, _XlcFileName
returns NULL.  The returned file name should be freed by
caller.

The rule for searching a file name is implementation depen-
dent.  In current implementation, _XlcFileName uses ``{cate-
gory}.dir'' file as mapping table, which has pairs of
strings, a full locale name and a corresponding file name.


9.  Utility Functions

Compare Latin-1 strings


int _XlcCompareISOLatin1(str1, str2)
      char *str1, *str2;


int _XlcNCompareISOLatin1(str1, str2, len)
      char *str1, *str2;
      int len;


The _XlcCompareIsoLatin1 function to compares two ISO-8859-1
strings.  Bytes representing ASCII lower case letters are



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Sample Implementation Frame Work	    X11, Release 6.4


converted to upper case before making the comparison.  The
value returned is an integer less than, equal to, or greater
than zero, depending on whether ``str1'' is lexicographicly
less than, equal to, or greater than ``str2''.

The _XlcNCompareIsoLatin1 function is identical to _XlcCom-
pareISOLatin1, except that at most ``len'' bytes are com-
pared.


Resource Utility


int XlcNumber(array)
      ArrayType array;


Similar to XtNumber.


void _XlcCopyFromArg(src, dst, size)
      char *src;
      char *dst;
      int size;


void _XlcCopyToArg(src, dst, size)
      char *src;
      char **dst;
      int size;


Similar to _XtCopyFromArg and _XtCopyToArg.


void _XlcCountVaList(var, count_ret)
      va_list var;
      int *count_ret;


Similar to _XtCountVaList.


void _XlcVaToArgList(var, count, args_ret)
      va_list var;
      int count;
      XlcArgList *args_ret;


Similar to _XtVaToArgList.


typedef struct _XlcResource {
      char *name;



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Sample Implementation Frame Work	    X11, Release 6.4


      XrmQuark xrm_name;
      int size;
      int offset;
      unsigned long mask;
} XlcResource, *XlcResourceList;



#define   XlcCreateMask 	 (1L<<0)
#define   XlcDefaultMask	 (1L<<1)
#define   XlcGetMask		 (1L<<2)
#define   XlcSetMask		 (1L<<3)
#define   XlcIgnoreMask 	 (1L<<4)



void _XlcCompileResourceList(resources, num_resources)
      XlcResourceList resources;
      int num_resources;


Similar to _XtCompileResourceList.


char * _XlcGetValues(base, resources, num_resources, args, num_args, mask)
      XPointer base;
      XlcResourceList resources;
      int num_resources;
      XlcArgList args;
      int num_args;
      unsigned long mask;


Similar to XtGetSubvalues.


char * _XlcSetValues(base, resources, num_resources, args, num_args, mask)
      XPointer base;
      XlcResourceList resources;
      int num_resources;
      XlcArgList args;
      int num_args;
      unsigned long mask;


Similar to XtSetSubvalues.


ANSI C Compatible Functions

The following are ANSI C/MSE Compatible Functions for non-
ANSI C environment.





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Sample Implementation Frame Work	    X11, Release 6.4


int _Xmblen(str, len)
      char *str;
      int len;


The _Xmblen function returns the number of characters
pointed to by ``str''.	Only ``len'' bytes in ``str'' are
used in determining the character count returned.  ``Str''
may point at characters from any valid codeset in the cur-
rent locale.

The call _Xmblen is equivalent to
     _Xmbtowc(_Xmbtowc((wchar_t*)NULL, str, len))


int _Xmbtowc(wstr, str, len)
      wchar_t *wstr;
      char *str;
      int len;


The _Xmbtowc function converts the character(s) pointed to
by ``str'' to their wide character representation(s) pointed
to by ``wstr''.  ``Len'' is the number of bytes in ``str''
to be converted.  The return value is the number of charac-
ters converted.

The call _Xmbtowc is equivalent to
     _Xlcmbtowc((XLCd)NULL, wstr, str, len)


int _Xlcmbtowc(lcd, wstr, str, len)
      XLCd lcd;
      wchar_t *wstr;
      char *str;
      int len;


The _Xlcmbtowc function is identical to _Xmbtowc, except
that it requires the ``lcd'' argument.	If ``lcd'' is (XLCd)
NULL, _Xlcmbtowc, calls _XlcCurrentLC to determine the cur-
rent locale.


int _Xwctomb(str, wc)
      char *str;
      wchar_t wc;


The _Xwctomb function converts a single wide character
pointed to by ``wc'' to its multibyte representation pointed
to by ``str''.	On success, the return value is 1.





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Sample Implementation Frame Work	    X11, Release 6.4


The call _Xwctomb is equivalent to
     _Xlcwctomb((XLCd)NULL, str, wstr)


int _Xlcwctomb(lcd, str, wc)
      XLCd lcd;
      char *str;
      wchar_t wc;


The _Xlcwctomb function is identical to _Xwctomb, except
that it requires the ``lcd'' argument.	If ``lcd'' is (XLCd)
NULL, _Xlcwctomb, calls _XlcCurrentLC to determine the cur-
rent locale.


int _Xmbstowcs(wstr, str, len)
      wchar_t *wstr;
      char *str;
      int len;


The _Xmbstowcs function converts the NULL-terminated string
pointed to by ``str'' to its wide character string represen-
tation pointed to by ``wstr''.	``Len'' is the number of
characters in ``str'' to be converted.

The call _Xmbstowcs is equivalent to
     _Xlcmbstowcs((XLCd)NULL, wstr, str, len)


int _Xlcmbstowcs(lcd, wstr, str, len)
      XLCd lcd;
      wchar_t *wstr;
      char *str;
      int len;


The _Xlcmbstowcs function is identical to _Xmbstowcs, except
that it requires the ``lcd'' argument.	If ``lcd'' is (XLCd)
NULL, _Xlcmbstowcs, calls _XlcCurrentLC to determine the
current locale.


int _Xwcstombs(str, wstr, len)
      char *str;
      wchar_t *wstr;
      int len;


The _Xwcstombs function converts the (wchar_t) NULL termi-
nated wide character string pointed to by ``wstr'' to the
NULL terminated multibyte string pointed to by ``str''.




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Sample Implementation Frame Work	    X11, Release 6.4


The call _Xwcstombs is equivalent to
     _Xlcwcstombs((XLCd)NULL, str, wstr, len)


int _Xlcwcstombs(lcd, str, wstr, len)
      XLCd lcd;
      char *str;
      wchar_t *wstr;
      int len;


The _Xlcwcstombs function is identical to _Xwcstombs, except
that it requires the ``lcd'' argument.	If ``lcd'' is (XLCd)
NULL, _Xlcwcstombs, calls _XlcCurrentLC to determine the
current locale.


int _Xwcslen(wstr)
      wchar_t *wstr;


The _Xwcslen function returns the count of wide characters
in the (wchar_t) NULL terminated wide character string
pointed to by ``wstr''.


wchar_t * _Xwcscpy(wstr1, wstr2)
      wchar_t *wstr1, *wstr2;


wchar_t * _Xwcsncpy(wstr1, wstr2, len)
      wchar_t *wstr1, *wstr2;
      int len;


The _Xwcscpy function copies the (wchar_t) NULL terminated
wide character string pointed to by ``wstr2'' to the object
pointed at by ``wstr1''.  ``Wstr1'' is (wchar_t) NULL termi-
nated.	The return value is a pointer to ``wstr1''.

The _Xwcsncpy function is identical to _Xwcscpy, except that
it copies ``len'' wide characters from the object pointed to
by ``wstr2'' to the object pointed to ``wstr1''.


int _Xwcscmp(wstr1, wstr2)
      wchar_t *wstr1, *wstr2;


int _Xwcsncmp(wstr1, wstr2, len)
      wchar_t *wstr1, *wstr2;
      int len;





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Sample Implementation Frame Work	    X11, Release 6.4


The _Xwcscmp function  compares two (wchar_t) NULL termi-
nated wide character strings.  The value returned is an
integer less than, equal to, or greater than zero, depending
on whether ``wstr1'' is lexicographicly less then, equal to,
or greater than ``str2''.

The _Xwcsncmp function is identical to _XlcCompareISOLatin1,
except that at most ``len'' wide characters are compared.

















































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