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			311 lines
		
	
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			311 lines
		
	
	
	
		
			8.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*   Some conversion functions for handling UTF-8
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|  *
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|  *   copyright Marcoen Hirschberg (2004,2005)
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|  *
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|  *   I got all the info from:
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|  *   http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
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|  *   and
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|  *   http://en.wikipedia.org/wiki/Unicode
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|  */
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| 
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| #include <stdio.h>
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| #include "file.h"
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| #include "debug.h"
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| #include "rbunicode.h"
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| 
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| #ifndef O_BINARY
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| #define O_BINARY 0
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| #endif
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| 
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| #define NUM_TABLES 5
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| #define NUM_CODEPAGES 13
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| 
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| static int default_codepage = 0;
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| static unsigned short codepage_table[MAX_CP_TABLE_SIZE];
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| static int loaded_cp_table = 0;
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| 
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| 
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| static const unsigned char utf8comp[6] = 
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| {
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|     0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC
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| };
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| 
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| static const char *filename[NUM_TABLES] =
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| {
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|     CODEPAGE_DIR"/iso.cp",
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|     CODEPAGE_DIR"/932.cp",  /* SJIS    */
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|     CODEPAGE_DIR"/936.cp",  /* GB2312  */
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|     CODEPAGE_DIR"/949.cp",  /* KSX1001 */
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|     CODEPAGE_DIR"/950.cp"   /* BIG5    */
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| };
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| 
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| static const char cp_2_table[NUM_CODEPAGES] =
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| {
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|     0, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 0
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| };
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| 
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| /* Load codepage file into memory */
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| int load_cp_table(int cp)
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| {
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|     int i=0;
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|     int table = cp_2_table[cp];
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|     int file, tablesize;
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|     unsigned char tmp[2];
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| 
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|     if (table == 0 || table == loaded_cp_table)
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|         return 1;
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| 
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|     file = open(filename[table-1], O_RDONLY|O_BINARY);
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| 
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|     if (file < 0) {
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|         DEBUGF("Can't open codepage file: %s.cp\n", filename[table-1]);
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|         return 0;
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|     }
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| 
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|     tablesize = filesize(file) / 2;
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| 
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|     if (tablesize > MAX_CP_TABLE_SIZE) {
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|         DEBUGF("Invalid codepage file: %s.cp\n", filename[table-1]);
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|         close(file);
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|         return 0;
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|     }
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| 
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|     while (i < tablesize) {
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|         if (!read(file, tmp, 2)) {
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|             DEBUGF("Can't read from codepage file: %s.cp\n", 
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|                     filename[table-1]);
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|             loaded_cp_table = 0;
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|             return 0;
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|         }
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|         codepage_table[i++] = (tmp[1] << 8) | tmp[0];
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|     }
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| 
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|     loaded_cp_table = table;
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|     close(file);
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|     return 1;
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| }
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| 
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| /* Encode a UCS value as UTF-8 and return a pointer after this UTF-8 char. */
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| unsigned char* utf8encode(unsigned long ucs, unsigned char *utf8)
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| {
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|     int tail = 0;
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| 
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|     if (ucs > 0x7F)
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|         while (ucs >> (5*tail + 6))
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|             tail++;
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| 
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|     *utf8++ = (ucs >> (6*tail)) | utf8comp[tail];
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|     while (tail--)
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|         *utf8++ = ((ucs >> (6*tail)) & (MASK ^ 0xFF)) | COMP;
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| 
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|     return utf8;
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| }
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| 
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| /* Recode an iso encoded string to UTF-8 */
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| unsigned char* iso_decode(const unsigned char *iso, unsigned char *utf8,
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|                           int cp, int count)
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| {
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|     unsigned short ucs, tmp;
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| 
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|     if (cp == -1) /* use default codepage */
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|         cp = default_codepage;
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| 
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|     if (!load_cp_table(cp)) cp = 0;
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| 
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|     while (count--) {
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|         if (*iso < 128 || cp == 0x0C) /* Already UTF-8 */
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|             *utf8++ = *iso++;
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| 
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|         else {
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| 
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|             /* cp tells us which codepage to convert from */
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|             switch (cp) {
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|                 case 0x01: /* Greek (ISO-8859-7) */
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|                 case 0x02: /* Hebrew (ISO-8859-8) */
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|                 case 0x03: /* Cyrillic (CP1251) */
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|                 case 0x04: /* Thai (ISO-8859-11) */
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|                 case 0x05: /* Arabic (CP1256) */
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|                 case 0x06: /* Turkish (ISO-8859-9) */
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|                 case 0x07: /* Latin Extended (ISO-8859-2) */
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|                     tmp = ((cp-1)*128) + (*iso++ - 128);
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|                     ucs = codepage_table[tmp];
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|                     break;
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| 
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|                 case 0x08: /* Japanese (SJIS) */
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|                     if (*iso > 0xA0 && *iso < 0xE0) {
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|                         tmp = *iso++ | (0xA100 - 0x8000);
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|                         ucs = codepage_table[tmp];
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|                         break;
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|                     }
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| 
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|                 case 0x09: /* Simplified Chinese (GB2312) */
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|                 case 0x0A: /* Korean (KSX1001) */
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|                 case 0x0B: /* Traditional Chinese (BIG5) */
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|                     if (count < 1 || !iso[1]) {
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|                         ucs = *iso++;
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|                         break;
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|                     }
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| 
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|                     /* we assume all cjk strings are written
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|                        in big endian order */
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|                     tmp = *iso++ << 8;
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|                     tmp |= *iso++;
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|                     tmp -= 0x8000;
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|                     ucs = codepage_table[tmp];
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|                     count--;
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|                     break;
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| 
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|                 default:
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|                     ucs = *iso++;
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|                     break;
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|             }
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| 
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|             if (ucs == 0) /* unknown char, use replacement char */
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|                 ucs = 0xfffd;
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|             utf8 = utf8encode(ucs, utf8);
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|         }
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|     }
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|     return utf8;
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| }
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| 
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| /* Recode a UTF-16 string with little-endian byte ordering to UTF-8 */
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| unsigned char* utf16LEdecode(const unsigned char *utf16, unsigned char *utf8,
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|         int count)
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| {
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|     unsigned long ucs;
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| 
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|     while (count > 0) {
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|         /* Check for a surrogate pair */
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|         if (utf16[1] >= 0xD8 && utf16[1] < 0xE0) {
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|             ucs = 0x10000 + ((utf16[0] << 10) | ((utf16[1] - 0xD8) << 18)
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|                     | utf16[2] | ((utf16[3] - 0xDC) << 8));
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|             utf16 += 4;
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|             count -= 2;
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|         } else {
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|             ucs = (utf16[0] | (utf16[1] << 8));
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|             utf16 += 2;
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|             count -= 1;
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|         }
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|         utf8 = utf8encode(ucs, utf8);
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|     }
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|     return utf8;
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| }
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| 
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| /* Recode a UTF-16 string with big-endian byte ordering to UTF-8 */
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| unsigned char* utf16BEdecode(const unsigned char *utf16, unsigned char *utf8,
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|         int count)
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| {
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|     unsigned long ucs;
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| 
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|     while (count > 0) {
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|         if (*utf16 >= 0xD8 && *utf16 < 0xE0) { /* Check for a surrogate pair */
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|             ucs = 0x10000 + (((utf16[0] - 0xD8) << 18) | (utf16[1] << 10)
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|                     | ((utf16[2] - 0xDC) << 8) | utf16[3]);
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|             utf16 += 4;
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|             count -= 2;
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|         } else {
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|             ucs = (utf16[0] << 8) | utf16[1];
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|             utf16 += 2;
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|             count -= 1;
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|         }
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|         utf8 = utf8encode(ucs, utf8);
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|     }
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|     return utf8;
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| }
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| 
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| /* Recode any UTF-16 string to UTF-8 */
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| unsigned char* utf16decode(const unsigned char *utf16, unsigned char *utf8,
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|         unsigned int count)
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| {
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|     unsigned long ucs;
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| 
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|     ucs = *(utf16++) << 8;
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|     ucs |= *(utf16++);
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| 
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|     if (ucs == 0xFEFF) /* Check for BOM */
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|         return utf16BEdecode(utf16, utf8, count-1);
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|     else if (ucs == 0xFFFE)
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|         return utf16LEdecode(utf16, utf8, count-1);
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|     else { /* ADDME: Should default be LE or BE? */
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|         utf16 -= 2;
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|         return utf16BEdecode(utf16, utf8, count);
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|     }
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| }
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| 
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| /* Return the number of UTF-8 chars in a string */
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| unsigned long utf8length(const unsigned char *utf8)
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| {
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|     unsigned long l = 0;
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| 
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|     while (*utf8 != 0)
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|         if ((*utf8++ & MASK) != COMP)
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|             l++;
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| 
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|     return l;
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| }
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| 
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| /* Decode 1 UTF-8 char and return a pointer to the next char. */
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| const unsigned char* utf8decode(const unsigned char *utf8, unsigned short *ucs)
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| {
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|     unsigned char c = *utf8++;
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|     unsigned long code;
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|     int tail = 0;
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| 
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|     if ((c <= 0x7f) || (c >= 0xc2)) {
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|         /* Start of new character. */
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|         if (c < 0x80) {        /* U-00000000 - U-0000007F, 1 byte */
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|             code = c;
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|         } else if (c < 0xe0) { /* U-00000080 - U-000007FF, 2 bytes */
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|             tail = 1;
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|             code = c & 0x1f;
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|         } else if (c < 0xf0) { /* U-00000800 - U-0000FFFF, 3 bytes */
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|             tail = 2;
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|             code = c & 0x0f;
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|         } else if (c < 0xf5) { /* U-00010000 - U-001FFFFF, 4 bytes */
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|             tail = 3;
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|             code = c & 0x07;
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|         } else {
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|             /* Invalid size. */
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|             code = 0xfffd;
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|         }
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| 
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|         while (tail-- && ((c = *utf8++) != 0)) {
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|             if ((c & 0xc0) == 0x80) {
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|                 /* Valid continuation character. */
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|                 code = (code << 6) | (c & 0x3f);
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| 
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|             } else {
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|                 /* Invalid continuation char */
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|                 code = 0xfffd;
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|                 utf8--;
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|                 break;
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|             }
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|         }
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|     } else {
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|         /* Invalid UTF-8 char */
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|         code = 0xfffd;
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|     }
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|     /* currently we don't support chars above U-FFFF */
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|     *ucs = (code < 0x10000) ? code : 0xfffd;
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|     return utf8;
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| }
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| 
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| void set_codepage(int cp)
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| {
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|     default_codepage = cp;
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|     return;
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| }
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| 
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| /* seek to a given char in a utf8 string and
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|    return its start position in the string */
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| int utf8seek(const unsigned char* utf8, int offset)
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| {
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|     int pos = 0;
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| 
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|     while (offset--) {
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|         pos++;
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|         while ((utf8[pos] & MASK) == COMP)
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|             pos++;
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|     }
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|     return pos;
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| }
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