utf8.h

/*
  Basic UTF-8 manipulation routines
  by Jeff Bezanson
  placed in the public domain Fall 2005
 
  This code is designed to provide the utilities you need to manipulate
  UTF-8 as an internal string encoding. These functions do not perform the
  error checking normally needed when handling UTF-8 data, so if you happen
  to be from the Unicode Consortium you will want to flay me alive.
  I do this because error checking can be performed at the boundaries (I/O),
  with these routines reserved for higher performance on data known to be
  valid.
  A UTF-8 validation routine is included.
*/
 
#ifndef UTF8_H
#define UTF8_H
 
#include <stdio.h>
#include <stdarg.h>
#include <wchar.h>
#include <wctype.h>
#include <stdarg.h>
 
#include <das3/defs.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
extern int locale_is_utf8;
 
/* is c the start of a utf8 sequence? */
#define isutf(c) (((c)&0xC0)!=0x80)
 
#define UEOF ((uint32_t)-1)
 
/* convert UTF-8 data to wide character */
DAS_API size_t u8_toucs(uint32_t *dest, size_t sz, const char *src, size_t srcsz);
 
/* the opposite conversion */
DAS_API size_t u8_toutf8(char *dest, size_t sz, const uint32_t *src, size_t srcsz);
 
/* single character to UTF-8, returns # bytes written */
DAS_API size_t u8_wc_toutf8(char *dest, uint32_t ch);
 
/* character number to byte offset */
DAS_API size_t u8_offset(const char *str, size_t charnum);
 
/* byte offset to character number */
DAS_API size_t u8_charnum(const char *s, size_t offset);
 
/* return next character, updating an index variable */
DAS_API uint32_t u8_nextchar(const char *s, size_t *i);
 
/* next character without NUL character terminator */
DAS_API uint32_t u8_nextmemchar(const char *s, size_t *i);
 
/* move to next character */
DAS_API void u8_inc(const char *s, size_t *i);
 
/* move to previous character */
DAS_API void u8_dec(const char *s, size_t *i);
 
/* returns length of next utf-8 sequence */
DAS_API size_t u8_seqlen(const char *s);
 
/* returns the # of bytes needed to encode a certain character */
DAS_API size_t u8_charlen(uint32_t ch);
 
/* computes the # of bytes needed to encode a WC string as UTF-8 */
DAS_API size_t u8_codingsize(uint32_t *wcstr, size_t n);
 
DAS_API char read_escape_control_char(char c);
 
/* assuming src points to the character after a backslash, read an
   escape sequence, storing the result in dest and returning the number of
   input characters processed */
DAS_API size_t u8_read_escape_sequence(const char *src, size_t ssz, uint32_t *dest);
 
/* given a wide character, convert it to an ASCII escape sequence stored in
   buf, where buf is "sz" bytes. returns the number of characters output.
   sz must be at least 3. */
DAS_API int u8_escape_wchar(char *buf, size_t sz, uint32_t ch);
 
/* convert a string "src" containing escape sequences to UTF-8 */
DAS_API size_t u8_unescape(char *buf, size_t sz, const char *src);
 
/* convert UTF-8 "src" to escape sequences.
 
   sz is buf size in bytes. must be at least 12.
 
   if escape_quotes is nonzero, quote characters will be escaped.
 
   if ascii is nonzero, the output is 7-bit ASCII, no UTF-8 survives.
 
   starts at src[*pi], updates *pi to point to the first unprocessed
   byte of the input.
 
   end is one more than the last allowable value of *pi.
 
   returns number of bytes placed in buf, including a NUL terminator.
*/
DAS_API size_t u8_escape(char *buf, size_t sz, const char *src, size_t *pi, size_t end,
                 int escape_quotes, int ascii);
 
/* utility predicates used by the above */
int octal_digit(char c);
int hex_digit(char c);
 
/* return a pointer to the first occurrence of ch in s, or NULL if not
   found. character index of found character returned in *charn. */
DAS_API char *u8_strchr(const char *s, uint32_t ch, size_t *charn);
 
/* same as the above, but searches a buffer of a given size instead of
   a NUL-terminated string. */
DAS_API char *u8_memchr(const char *s, uint32_t ch, size_t sz, size_t *charn);
 
DAS_API char *u8_memrchr(const char *s, uint32_t ch, size_t sz);
 
/* count the number of characters in a UTF-8 string */
DAS_API size_t u8_strlen(const char *s);
 
/* number of columns occupied by a string */
DAS_API size_t u8_strwidth(const char *s);
 
/* Only works on Linux.
 * TODO: Update this function to pickup Windows Code-page 65001, which is
 * a UTF-8 implementation 
 */
DAS_API int u8_is_locale_utf8(const char *locale);
 
/* printf where the format string and arguments may be in UTF-8.
   you can avoid this function and just use ordinary printf() if the current
   locale is UTF-8. */
DAS_API size_t u8_vprintf(const char *fmt, va_list ap);
DAS_API size_t u8_printf(const char *fmt, ...);
 
/* determine whether a sequence of bytes is valid UTF-8. length is in bytes */
DAS_API int u8_isvalid(const char *str, size_t length);
 
/* reverse a UTF-8 string. len is length in bytes. dest and src must both
   be allocated to at least len+1 bytes. returns 1 for error, 0 otherwise */
DAS_API int u8_reverse(char *dest, char *src, size_t len);
 
DAS_API char* u8_strncpy(char* dest, const char* src, size_t len);
 
#ifdef __cplusplus
}
#endif
 
 
#endif