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system76-edk2/StdLib/LibC/Locale/multibyte_Utf8.c
Daryl McDaniel 450ea6d5b6 StdLib: Clarify and improve comments. 
Indentation has been corrected in all of the files.

LibC/Locale/multibyte_Utf8.c
LibC/Uefi/SysCalls.c
  Clarify and improve comments.

Include/sys/termios.h
  Add parameter names to function prototypes as referenced in the comments.

StdLibPrivateInternalFiles\Include\kfile.h
  Add comment for the fo_close fileop.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Daryl McDaniel <edk2-lists@mc2research.org>
Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19588 6f19259b-4bc3-4df7-8a09-765794883524
2016-01-06 00:31:42 +00:00

1011 lines
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/** @file
Copyright (c) 2016, Daryl McDaniel. All rights reserved.<BR>
Copyright (c) 2012, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <assert.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <wchar.h>
#include <sys/types.h>
#include <limits.h>
typedef int ch_UCS4;
static mbstate_t LocalConvState = {0};
/** Map a UTF-8 encoded prefix byte to a sequence length.
Zero means illegal prefix, but valid surrogate if < 0xC0.
One indicates an ASCII-7 equivalent character.
Two, three, and four are the first byte for 2, 3, and 4 byte sequences, respectively.
See RFC 3629 for details.
TABLE ENCODING:
Low Nibble decodes the first byte into the number of bytes in the sequence.
A value of zero indicates an invalid byte.
The High Nibble encodes a bit mask to be used to match against the high nibble of the second byte.
example:
SequenceLength = code[c0] & 0x0F;
Mask = 0x80 | code[c0];
Surrogate bytes are valid if: code[cX] & Mask > 0x80;
*/
static
UINT8 utf8_code_length[256] = {
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, /* 00-0F */
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, /* 70-7F */
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, /* 80-8F */
0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, /* 90-9F */
0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, /* A0-AF */
0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, 0xC0, /* B0-BF */
0x00, 0x00, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, /* C0-C1 + C2-CF */
0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, /* D0-DF */
0x43, 0x73, 0x73, 0x73, 0x73, 0x73, 0x73, 0x73, 0x73, 0x73, 0x73, 0x73, 0x73, 0x33, 0x73, 0x73, /* E0-EF */
0x64, 0x74, 0x74, 0x74, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 /* F0-F4 + F5-FF */
};
/** Process one byte of a multibyte character.
@param[in] ch One byte of a multibyte character.
@param[in,out] ps Pointer to a conversion state object.
@retval -2 ch is an incomplete but potentially valid character.
@retval -1 ch is not valid in this context.
@retval 1:4 The length, in bytes, of the character ch just completed.
**/
static
int
ProcessOneByte(unsigned char ch, mbstate_t *ps)
{
UINT32 Mask;
UINT32 Length;
int RetVal = 0;
if(ps->A > 3) {
// We are in an invalid state
ps->A = 0; // Initial State
}
ps->C[ps->A] = ch; // Save the current byte
Mask = utf8_code_length[ch];
if(ps->A == 0) { // Initial State. First byte of sequence.
ps->E = Mask | 0x80;
Length = Mask & 0xF;
switch(Length) {
case 0: // State 0, Code 0
errno = EILSEQ;
RetVal = -1;
ps->E = 1; // Consume this byte
break;
case 1: // State 0, Code 1
// ASCII-7 Character
ps->B = ps->D[0] = ch;
RetVal = 1;
break;
default: // State 0, Code 2, 3, 4
ps->A = 1; // Next state is State-1
RetVal = -2; // Incomplete but potentially valid character
break;
}
}
else {
// We are in state 1, 2, or 3 and processing a surrogate byte
Length = ps->E & 0xF;
if((Mask & ps->E) > 0x80) {
// This byte is valid
switch(ps->A) { // Process based upon our current state
case 1: // Second byte of the sequence.
if(Length == 2) { // State 1, Code 2
Length = ((ps->C[0] & 0x1f) << 6) + (ps->C[1] & 0x3f);
assert ((Length > 0x007F) && (Length <= 0x07FF));
ps->B = ps->D[0] = (UINT16)Length;
ps->A = 0; // Next state is State-0
RetVal = 2;
}
else { // This isn't the last byte, get more. State 1, Code 3 or 4
ps->A = 2;
RetVal = -2;
}
break;
case 2: // Third byte of the sequence
if(Length == 3) {
Length = ((ps->C[0] & 0x0f) << 12) + ((ps->C[1] & 0x3f) << 6) + (ps->C[2] & 0x3f);
assert ((Length > 0x07FF) && (Length <= 0xFFFF));
ps->B = ps->D[0] = (UINT16)Length;
ps->A = 0; // Next state is State-0
RetVal = 3;
}
else {
ps->A = 3;
RetVal = -2;
}
break;
case 3: // Fourth byte of the sequence
if(Length == 4) {
Length = ((ps->C[0] & 0x7) << 18) + ((ps->C[1] & 0x3f) << 12) +
((ps->C[2] & 0x3f) << 6) + (ps->C[3] & 0x3f);
ps->B = Length;
assert ((Length > 0xFFFF) && (Length <= 0x10ffff));
/* compute and append the two surrogates: */
/* translate from 10000..10FFFF to 0..FFFF */
Length -= 0x10000;
/* high surrogate = top 10 bits added to D800 */
ps->D[0] = (UINT16)(0xD800 + (Length >> 10));
/* low surrogate = bottom 10 bits added to DC00 */
ps->D[1] = (UINT16)(0xDC00 + (Length & 0x03FF));
ps->A = 0; // Next state is State-0
RetVal = 4;
}
else {
errno = EILSEQ;
ps->A = 0;
RetVal = -1;
ps->E = 4; // Can't happen, but consume this byte anyway
}
break;
}
}
else { // Invalid surrogate byte
errno = EILSEQ;
ps->A = 0; // Next is State-0
RetVal = -1;
ps->E = 0; // Don't Consume, it may be an initial byte
}
}
return RetVal;
}
/** Convert one Multibyte sequence.
@param[out] Dest Pointer to output location, or NULL
@param[in] Src Multibyte Source (UTF8)
@param[in] Len Max Number of bytes to convert
@param[in] pS Pointer to State struct., or NULL
@retval -2 Bytes processed comprise an incomplete, but potentially valid, character.
@retval -1 An encoding error was encountered. ps->E indicates the number of bytes consumed.
@retval 0 Either Src is NULL or it points to a NUL character.
@retval 1:N N bytes were consumed producing a valid wide character.
**/
int
DecodeOneStateful(
wchar_t *Dest, // Pointer to output location, or NULL
const char *Src, // Multibyte Source (UTF8)
ssize_t Len, // Max Number of bytes to convert
mbstate_t *pS // Pointer to State struct., or NULL
)
{
const char *SrcEnd;
int NumConv;
unsigned char ch;
if(pS == NULL) {
pS = &LocalConvState;
}
NumConv = 0;
if(Src != NULL) {
if(*Src != 0) {
SrcEnd = Src + Len;
while(Src < SrcEnd) {
ch = (unsigned char)*Src++;
NumConv = ProcessOneByte(ch, pS);
if(NumConv != -2) {
break;
}
}
}
else if(Dest != NULL) {
*Dest = 0;
}
}
if((NumConv > 0) && (Dest != NULL)) {
Dest[0] = pS->D[0];
if(NumConv == 4) {
Dest[1] = pS->D[1];
}
}
return NumConv;
}
/* Determine the number of bytes needed to represent a Wide character
as a MBCS character.
A single wide character may convert into a one, two, three, or four byte
narrow (MBCS or UTF-8) character. The number of MBCS bytes can be determined
as follows.
If WCS char < 0x00000080 One Byte
Else if WCS char < 0x0000D800 Two Bytes
Else Three Bytes
Since UEFI only supports the Unicode Base Multilingual Plane (BMP),
Four-byte characters are not supported.
@param[in] InCh Wide character to test.
@retval -1 Improperly formed character
@retval 0 InCh is 0x0000
@retval >0 Number of bytes needed for the MBCS character
*/
int
EFIAPI
OneWcToMcLen(const wchar_t InCh)
{
ssize_t NumBytes;
if(InCh == 0) { // Is this a NUL, 0x0000 ?
NumBytes = 0;
}
else if(InCh < 0x0080) { // Is this a 1-byte character?
NumBytes = 1;
}
else if(InCh < 0x0800) { // Is this a 2-byte character?
NumBytes = 2;
}
else if((InCh >= 0xD800) && (InCh < 0xE000)) { // Is this a surrogate?
NumBytes = -1;
}
else {
NumBytes = 3; // Otherwise, it must be a 3-byte character.
}
return (int)NumBytes; // Return extimate of required bytes.
}
/* Determine the number of bytes needed to represent a Wide character string
as a MBCS string of given maximum length. Will optionally return the number
of wide characters that would be consumed.
A single wide character may convert into a one, two, three, or four byte
narrow (MBCS or UTF-8) character. The number of MBCS bytes can be determined
as follows.
If WCS char < 0x00000080 One Byte
Else if WCS char < 0x00000800 Two Bytes
Else if WCS char < 0x00010000 Three Bytes
Else Four Bytes
Since UEFI only supports the Unicode Base Multilingual Plane (BMP),
Four-byte characters should not be encountered.
@param[in] Src Pointer to a wide character string.
@param[in] Limit Maximum number of bytes the converted string may occupy.
@param[out] NumChar Pointer to where to store the number of wide characters
consumed, or NULL.
@return The number of bytes required to convert Src to MBCS,
not including the terminating NUL. If NumChar is not NULL, the number
of characters represented by the return value will be written to
where it points.
*/
size_t
EFIAPI
EstimateWtoM(const wchar_t * Src, size_t Limit, size_t *NumChar)
{
ssize_t Estimate;
size_t CharCount;
ssize_t NumBytes;
wchar_t EChar;
Estimate = 0;
CharCount = 0;
EChar = *Src++; // Get the initial character and point to next
while(((NumBytes = OneWcToMcLen(EChar)) > 0) &&
((size_t)(Estimate + NumBytes) < Limit))
{ // Until one of the source characters is NUL
++CharCount; // Count this character.
Estimate += NumBytes; // Count the Bytes for this character
EChar = *Src++; // Get the next source character and point to the next.
}
if(NumChar != NULL) {
*NumChar = CharCount;
}
return (size_t)Estimate; // Return esimate of required bytes.
}
/* Determine the number of characters in a MBCS string.
MBCS characters are one to four bytes long. By examining the first byte
of a MBCS character, one can determine the number of bytes comprising the
character.
0x00 - 0x7F One
0xC0 - 0xDF Two
0xE0 - 0xEF Three
0xF0 - 0xF7 Four
Since UEFI only supports the Unicode Base Multilingual Plane (BMP),
Four-byte characters should not be encountered.
@param[in] Src The string to examine
@return The number of characters represented by the MBCS string.
**/
size_t
EFIAPI
CountMbcsChars(const char *Src)
{
size_t Count;
char EChar;
Count = 0;
EChar = *Src++;
while(EChar != 0) {
if(EChar < 0x80) {
++Count;
}
else if(EChar < 0xE0) {
Count += 2;
++Src;
}
else if(EChar < 0xF0) {
Count += 3;
Src += 2;
}
else {
// Ill-formed character
break;
}
}
return Count;
}
/** Convert a wide character (UTF16) into a multibyte character (UTF8)
Converts a wide character into a corresponding multibyte character that
begins in the conversion state described by the object pointed to by ps.
If dst is not a null pointer, the converted character is then stored into
the array pointed to by dst.
It is the caller's responsibility to ensure that Dest is large enough to
hold the resulting MBCS sequence.
@param s Pointer to the wide-character string to convert
@param Dest Pointer to the buffer in which to place the converted sequence, or NULL.
@retval -1 An error occurred. The error reason is in errno.
@retval >=0 The number of bytes stored into Dest.
**/
ssize_t
EncodeUtf8(char *Dest, wchar_t ch)
{
char *p; /* next free byte in build buffer */
int NumInBuff; // number of bytes in Buff
char Buff[4]; // Buffer into which each character is built
p = Buff;
NumInBuff = 0;
if (ch < 0x80) {
/* Encode ASCII -- One Byte */
*p++ = (char) ch;
NumInBuff = 1;
}
else if (ch < 0x0800) {
/* Encode Latin-1 -- Two Byte */
*p++ = (char)(0xc0 | (ch >> 6));
*p++ = (char)(0x80 | (ch & 0x3f));
NumInBuff = 2;
}
else {
/* Encode UCS2 Unicode ordinals -- Three Byte */
/* Special case: check for surrogate -- Shouldn't happen in UEFI */
if (0xD800 <= ch && ch < 0xE000) {
errno = EILSEQ;
return -1;
}
else {
*p++ = (char)(0xe0 | (ch >> 12));
*p++ = (char)(0x80 | ((ch >> 6) & 0x3f));
*p++ = (char)(0x80 | (ch & 0x3f));
NumInBuff = 3;
}
}
/* At this point, Buff holds the converted character which is NumInBuff bytes long.
NumInBuff is the value 1, 2, 3, or 4
*/
if(Dest != NULL) { // Save character if Dest is not NULL
memcpy(Dest, Buff, NumInBuff);
}
return NumInBuff; // Tell the caller
}
// ######################## Narrow to Wide Conversions #######################
/** If ps is not a null pointer, the mbsinit function determines whether the
pointed-to mbstate_t object describes an initial conversion state.
@param[in] ps Pointer to the conversion state object to test.
@return The mbsinit function returns nonzero if ps is a null pointer
or if the pointed-to object describes an initial conversion
state; otherwise, it returns zero.
Declared in: wchar.h
**/
int
mbsinit(const mbstate_t *ps)
{
if((ps == NULL) || (ps->A == 0)) {
return 1;
}
return 0;
}
/** The mbrlen function is equivalent to the call:<BR>
@verbatim
mbrtowc(NULL, s, n, ps != NULL ? ps : &internal)
@endverbatim
where internal is the mbstate_t object for the mbrlen function, except that
the expression designated by ps is evaluated only once.
@param[in] s Pointer to a multibyte character sequence.
@param[in] n Maximum number of bytes to examine.
@param[in] pS Pointer to the conversion state object.
@retval 0 The next n or fewer characters complete a NUL.
@retval 1..n The number of bytes that complete the multibyte character.
@retval -2 The next n bytes contribute to an incomplete (but potentially valid) multibyte character.
@retval -1 An encoding error occurred.
Declared in: wchar.h
**/
size_t
mbrlen(
const char *s,
size_t n,
mbstate_t *pS
)
{
return mbrtowc(NULL, s, n, pS);
}
/** Determine the number of bytes comprising a multibyte character.
If S is not a null pointer, the mblen function determines the number of bytes
contained in the multibyte character pointed to by S. Except that the
conversion state of the mbtowc function is not affected, it is equivalent to
mbtowc((wchar_t *)0, S, N);
@param[in] S NULL to query whether multibyte characters have
state-dependent encodings. Otherwise, points to a
multibyte character.
@param[in] N The maximum number of bytes in a multibyte character.
@return If S is a null pointer, the mblen function returns a nonzero or
zero value, if multibyte character encodings, respectively, do
or do not have state-dependent encodings. If S is not a null
pointer, the mblen function either returns 0 (if S points to the
null character), or returns the number of bytes that are contained
in the multibyte character (if the next N or fewer bytes form a
valid multibyte character), or returns -1 (if they do not form a
valid multibyte character).
Declared in: stdlib.h
**/
int
mblen(
const char *s,
size_t n
)
{
return (int)mbrlen(s, n, NULL);
}
/**
If S is a null pointer, the mbrtowc function is equivalent to the call:<BR>
@verbatim
mbrtowc(NULL, "", 1, ps)
@endverbatim
In this case, the values of the parameters pwc and n are ignored.
If S is not a null pointer, the mbrtowc function inspects at most n bytes beginning with
the byte pointed to by S to determine the number of bytes needed to complete the next
multibyte character (including any shift sequences). If the function determines that the
next multibyte character is complete and valid, it determines the value of the
corresponding wide character and then, if pwc is not a null pointer, stores that value in
the object pointed to by pwc. If the corresponding wide character is the null wide
character, the resulting state described is the initial conversion state.
@param[out] pwc Pointer to where the resulting wide character is to be stored.
@param[in] s Pointer to a multibyte character "string".
@param[in] n The maximum number of bytes to inspect.
@param[in] ps Pointer to a conversion state object.
@retval 0 if the next n or fewer bytes complete the multibyte
character that corresponds to the null wide
character (which is the value stored).
@retval between_1_and_n_inclusive if the next n or fewer bytes complete
a valid multibyte character (which is the value
stored); the value returned is the number of bytes
that complete the multibyte character.
@retval (size_t)(-2) if the next n bytes contribute to an incomplete
(but potentially valid) multibyte character, and
all n bytes have been processed (no value is stored).
@retval (size_t)(-1) if an encoding error occurs, in which case the next
n or fewer bytes do not contribute to a complete and
valid multibyte character (no value is stored); the
value of the macro EILSEQ is stored in errno, and
the conversion state is unspecified.
Declared in: wchar.h
**/
size_t
mbrtowc(
wchar_t *pwc,
const char *s,
size_t n,
mbstate_t *ps
)
{
int RetVal;
RetVal = DecodeOneStateful(pwc, s, (ssize_t)n, ps);
return (size_t)RetVal;
}
/** Convert a multibyte character into a wide character.
If S is not a null pointer, the mbtowc function inspects at most N bytes
beginning with the byte pointed to by S to determine the number of bytes
needed to complete the next multibyte character (including any shift
sequences). If the function determines that the next multibyte character
is complete and valid, it determines the value of the corresponding wide
character and then, if Pwc is not a null pointer, stores that value in
the object pointed to by Pwc. If the corresponding wide character is the
null wide character, the function is left in the initial conversion state.
@param[out] Pwc Pointer to a wide-character object to receive the converted character.
@param[in] S Pointer to a multibyte character to convert.
@param[in] N Maximum number of bytes in a multibyte character.
@return If S is a null pointer, the mbtowc function returns a nonzero or
zero value, if multibyte character encodings, respectively, do
or do not have state-dependent encodings. If S is not a null
pointer, the mbtowc function either returns 0 (if S points to
the null character), or returns the number of bytes that are
contained in the converted multibyte character (if the next N or
fewer bytes form a valid multibyte character), or returns -1
(if they do not form a valid multibyte character).
In no case will the value returned be greater than N or the value
of the MB_CUR_MAX macro.
Declared in: stdlib.h
**/
int
mbtowc(
wchar_t *pwc,
const char *s,
size_t n
)
{
return (int)mbrtowc(pwc, s, n, NULL);
}
/**
The mbsrtowcs function converts a sequence of multibyte characters that begins in the
conversion state described by the object pointed to by ps, from the array indirectly
pointed to by src into a sequence of corresponding wide characters. If dst is not a null
pointer, the converted characters are stored into the array pointed to by dst. Conversion
continues up to and including a terminating null character, which is also stored.
Conversion stops earlier in two cases: when a sequence of bytes is encountered that does
not form a valid multibyte character, or (if dst is not a null pointer) when len wide
characters have been stored into the array pointed to by dst. Each conversion takes
place as if by a call to the mbrtowc function.
If dst is not a null pointer, the pointer object pointed to by src is assigned either a null
pointer (if conversion stopped due to reaching a terminating null character) or the address
just past the last multibyte character converted (if any). If conversion stopped due to
reaching a terminating null character and if dst is not a null pointer, the resulting state
described is the initial conversion state.
@param[out] dst Pointer to where the resulting wide character sequence is stored.
@param[in] src Pointer to a pointer to the multibyte character sequence to convert.
@param[in] len Maximum number of wide characters to be stored into dst.
@param[in] ps Pointer to a conversion state object.
@return If the input conversion encounters a sequence of bytes that do
not form a valid multibyte character, an encoding error occurs:
the mbsrtowcs function stores the value of the macro EILSEQ in
errno and returns (size_t)(-1); the conversion state is
unspecified. Otherwise, it returns the number of multibyte
characters successfully converted, not including the terminating
null character (if any).
Declared in: wchar.h
**/
size_t
mbsrtowcs(
wchar_t *dst,
const char **src,
size_t len,
mbstate_t *ps
)
{
int x;
size_t RetVal = 0;
const char *MySrc;
if((src == NULL) || (*src == NULL)) {
return 0;
}
MySrc = *src;
for(x = 1 ; (len != 0) && (x > 0); --len) {
x = DecodeOneStateful(dst, MySrc, MB_LEN_MAX, ps);
switch(x) {
case -2: // Incomplete character
case -1: // Encoding error
RetVal = (size_t)x;
break;
case 0: // Encountered NUL character: done.
if(dst != NULL) {
*dst = 0;
*src = NULL;
}
break;
default: // Successfully decoded a character, continue with next
MySrc += x;
if(dst != NULL) {
++dst;
if(x == 4) {
++dst;
}
*src = MySrc;
}
++RetVal;
break;
}
}
return RetVal;
}
/** Convert a multibyte character string into a wide-character string.
The mbstowcs function converts a sequence of multibyte characters that
begins in the initial shift state from the array pointed to by Src into
a sequence of corresponding wide characters and stores not more than limit
wide characters into the array pointed to by Dest. No multibyte
characters that follow a null character (which is converted into a null
wide character) will be examined or converted. Each multibyte character
is converted as if by a call to the mbtowc function, except that the
conversion state of the mbtowc function is not affected.
No more than Limit elements will be modified in the array pointed to by Dest.
If copying takes place between objects that overlap,
the behavior is undefined.
@param[out] Dest Pointer to the array to receive the converted string.
@param[in] Src Pointer to the string to be converted.
@param[in] Limit Maximum number of elements to be written to Dest.
@return If an invalid multibyte character is encountered, the mbstowcs
function returns (size_t)(-1). Otherwise, the mbstowcs function
returns the number of array elements modified, not including a
terminating null wide character, if any.
Declared in: stdlib.h
**/
size_t
mbstowcs(
wchar_t *Dest,
const char *Src,
size_t Limit
)
{
/* Dest may be NULL */
/* Src may be NULL */
return mbsrtowcs(Dest, &Src, Limit, NULL);
}
/** The btowc function determines whether C constitutes a valid single-byte
character in the initial shift state.
@param[in] C A narrow character to test or convert to wide.
@return The btowc function returns WEOF if c has the value EOF or if
(unsigned char)C does not constitute a valid single-byte
character in the initial shift state. Otherwise, it returns the
wide character representation of that character.
Declared in: wchar.h
**/
wint_t
btowc(int c)
{
int x;
wchar_t Dest;
wint_t RetVal = WEOF;
if (c == EOF)
return WEOF;
x = DecodeOneStateful(&Dest, (const char *)&c, 1, NULL);
if(x == 0) {
RetVal = 0;
}
else if(x == 1) {
RetVal = (wint_t)Dest;
}
return RetVal;
}
// ######################## Wide to Narrow Conversions #######################
/**
If S is a null pointer, the wcrtomb function is equivalent to the call:<BR>
@verbatim
wcrtomb(buf, L'\0', ps)
@endverbatim
where buf is an internal buffer.
If S is not a null pointer, the wcrtomb function determines the number of bytes needed
to represent the multibyte character that corresponds to the wide character given by wc
(including any shift sequences), and stores the multibyte character representation in the
array whose first element is pointed to by S. At most MB_CUR_MAX bytes are stored. If
wc is a null wide character, a null byte is stored, preceded by any shift sequence needed
to restore the initial shift state; the resulting state described is the initial conversion state.
@param[out] Dest Pointer to the location in which to store the resulting
multibyte character. Otherwise, NULL to reset the
conversion state.
@param[in] wchar The wide character to convert.
@param[in,out] pS Pointer to a conversion state object, or NULL.
@return The wcrtomb function returns the number of bytes stored in the
array object (including any shift sequences). When wc is not a
valid wide character, an encoding error occurs: the function
stores the value of the macro EILSEQ in errno and
returns (size_t)(-1); the conversion state is unspecified.
Declared in: wchar.h
**/
size_t
wcrtomb(
char *Dest,
wchar_t wchar,
mbstate_t *pS
)
{
size_t RetVal;
/* Dest may be NULL */
if (Dest == NULL) {
RetVal = 1;
}
else {
if (wchar == L'\0') {
*Dest = '\0';
RetVal = 1;
}
else {
RetVal = EncodeUtf8(Dest, wchar);
}
}
if(pS == NULL) {
pS = &LocalConvState;
}
pS->A = 0; // Set ps to the initial conversion state
return RetVal;
}
/** Convert a wide character into a multibyte character.
The wctomb function determines the number of bytes needed to represent the
multibyte character corresponding to the wide character given by WC
(including any shift sequences), and stores the multibyte character
representation in the array whose first element is pointed to by S (if S is
not a null pointer). At most MB_CUR_MAX characters are stored. If WC is a
null wide character, a null byte is stored, preceded by any shift sequence
needed to restore the initial shift state, and the function is left in the
initial conversion state.
@param[out] S Pointer to the object to receive the converted multibyte character.
@param[in] WC Wide character to be converted.
@return If S is a null pointer, the wctomb function returns a nonzero or
zero value, if multibyte character encodings, respectively, do or
do not have state-dependent encodings. If S is not a null pointer,
the wctomb function returns -1 if the value of WC does not
correspond to a valid multibyte character, or returns the number
of bytes that are contained in the multibyte character
corresponding to the value of WC.
In no case will the value returned be greater than the value of
the MB_CUR_MAX macro.
Declared in: stdlib.h
**/
int
wctomb(
char *s,
wchar_t wchar
)
{
/*
If s is NULL just return whether MB Characters have state
dependent encodings -- they don't.
*/
if (s == NULL)
return 0;
return (int)wcrtomb(s, wchar, NULL);
}
/** The wcsrtombs function converts a sequence of wide characters from the array
indirectly pointed to by Src into a sequence of corresponding multibyte
characters that begins in the conversion state described by the object
pointed to by ps.
If Dest is not a null pointer, the converted characters are stored into the
array pointed to by Dest. Conversion continues up to and including a
terminating null wide character, which is also stored. Conversion stops
earlier in two cases: when a wide character is reached that does not
correspond to a valid multibyte character, or (if Dest is not a null
pointer) when the next multibyte character would exceed the limit of Limit
total bytes to be stored into the array pointed to by Dest. Each conversion
takes place as if by a call to the wcrtomb function.)
If Dest is not a null pointer, the pointer object pointed to by Src is
assigned either a null pointer (if conversion stopped due to reaching
a terminating null wide character) or the address just past the last wide
character converted (if any). If conversion stopped due to reaching a
terminating null wide character, the resulting state described is the
initial conversion state.
@param[in] Dest
@param[in,out] Src
@param[in] Limit Max number of bytes to store in Dest.
@param[in,out] ps
@return If conversion stops because a wide character is reached that
does not correspond to a valid multibyte character, an
encoding error occurs: the wcsrtombs function stores the
value of the macro EILSEQ in errno and returns (size_t)(-1);
the conversion state is unspecified. Otherwise, it returns
the number of bytes in the resulting multibyte character
sequence, not including the terminating null character (if any).
Declared in: wchar.h
**/
size_t
wcsrtombs(
char *Dest,
const wchar_t **Src,
size_t Limit,
mbstate_t *ps
)
{
size_t NumStored;
ssize_t MaxBytes;
int count;
wchar_t InCh;
NumStored = 0;
MaxBytes = (ssize_t)Limit;
/* Dest may be NULL */
/* Src may be NULL */
/* ps appears to be unused */
if (Src == NULL || *Src == NULL)
return (0);
if (Dest == NULL) {
NumStored = EstimateWtoM(*Src, ASCII_STRING_MAX, NULL);
}
else {
if((MaxBytes < 0) || (MaxBytes > ASCII_STRING_MAX)) {
MaxBytes = ASCII_STRING_MAX;
}
while ((MaxBytes > 0) && (OneWcToMcLen(InCh = *(*Src)++) <= MaxBytes)) {
if(InCh == 0) {
*Src = NULL;
*Dest = 0; // NUL terminate Dest string, but don't count the NUL
break;
}
count = (int)wcrtomb(Dest, InCh, NULL);
if(count >= 0) {
Dest += count;
MaxBytes -= count;
NumStored += count;
}
else {
NumStored = (size_t)(-1);
}
}
}
return NumStored;
}
/** Convert a wide-character string into a multibyte character string.
The wcstombs function converts a sequence of wide characters from the
array pointed to by Src into a sequence of corresponding multibyte
characters that begins in the initial shift state, and stores these
multibyte characters into the array pointed to by Dest, stopping if a
multibyte character would exceed the limit of Limit total bytes or if a
null character is stored. Each wide character is converted as if by
a call to the wctomb function, except that the conversion state of
the wctomb function is not affected.
No more than Limit bytes will be modified in the array pointed to by Dest.
If copying takes place between objects that overlap,
the behavior is undefined.
@param[out] Dest Pointer to the array to receive the converted string.
@param[in] Src Pointer to the string to be converted.
@param[in] Limit Maximum number of elements to be written to Dest.
@return If a wide character is encountered that does not correspond to a
valid multibyte character, the wcstombs function returns
(size_t)(-1). Otherwise, the wcstombs function returns the number
of bytes in the resulting multibyte character sequence,
not including the terminating null character (if any).
Declared in: stdlib.h
**/
size_t
wcstombs(
char *Dest,
const wchar_t *Src,
size_t Limit
)
{
/* Dest may be NULL */
return wcsrtombs(Dest, &Src, Limit, NULL);
}
/** The wctob function determines whether C corresponds to a member of the extended
character set whose multibyte character representation is a single byte when in the initial
shift state.
wctob needs to be consistent with wcrtomb.
If wcrtomb says that a character is representable in 1 byte,
then wctob needs to also represent the character as 1 byte.
@return The wctob function returns EOF if C does not correspond to a multibyte
character with length one in the initial shift state. Otherwise, it
returns the single-byte representation of that character as an
unsigned char converted to an int.
Declared in: wchar.h
**/
int
wctob(wint_t c)
{
int RetVal;
RetVal = EOF;
if(c == 0) {
RetVal = 0;
}
else if (OneWcToMcLen((const wchar_t)c) == 1) {
RetVal = (int)(c & 0xFF);
}
return RetVal;
}
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