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      1 /*
      2  * string.c : an XML string utilities module
      3  *
      4  * This module provides various utility functions for manipulating
      5  * the xmlChar* type. All functions named xmlStr* have been moved here
      6  * from the parser.c file (their original home).
      7  *
      8  * See Copyright for the status of this software.
      9  *
     10  * UTF8 string routines from:
     11  * William Brack <wbrack (at) mmm.com.hk>
     12  *
     13  * daniel (at) veillard.com
     14  */
     15 
     16 #define IN_LIBXML
     17 #include "libxml.h"
     18 
     19 #include <stdlib.h>
     20 #include <string.h>
     21 #include <libxml/xmlmemory.h>
     22 #include <libxml/parserInternals.h>
     23 #include <libxml/xmlstring.h>
     24 
     25 /************************************************************************
     26  *                                                                      *
     27  *                Commodity functions to handle xmlChars                *
     28  *                                                                      *
     29  ************************************************************************/
     30 
     31 /**
     32  * xmlStrndup:
     33  * @cur:  the input xmlChar *
     34  * @len:  the len of @cur
     35  *
     36  * a strndup for array of xmlChar's
     37  *
     38  * Returns a new xmlChar * or NULL
     39  */
     40 xmlChar *
     41 xmlStrndup(const xmlChar *cur, int len) {
     42     xmlChar *ret;
     43 
     44     if ((cur == NULL) || (len < 0)) return(NULL);
     45     ret = (xmlChar *) xmlMallocAtomic((len + 1) * sizeof(xmlChar));
     46     if (ret == NULL) {
     47         xmlErrMemory(NULL, NULL);
     48         return(NULL);
     49     }
     50     memcpy(ret, cur, len * sizeof(xmlChar));
     51     ret[len] = 0;
     52     return(ret);
     53 }
     54 
     55 /**
     56  * xmlStrdup:
     57  * @cur:  the input xmlChar *
     58  *
     59  * a strdup for array of xmlChar's. Since they are supposed to be
     60  * encoded in UTF-8 or an encoding with 8bit based chars, we assume
     61  * a termination mark of '0'.
     62  *
     63  * Returns a new xmlChar * or NULL
     64  */
     65 xmlChar *
     66 xmlStrdup(const xmlChar *cur) {
     67     const xmlChar *p = cur;
     68 
     69     if (cur == NULL) return(NULL);
     70     while (*p != 0) p++; /* non input consuming */
     71     return(xmlStrndup(cur, p - cur));
     72 }
     73 
     74 /**
     75  * xmlCharStrndup:
     76  * @cur:  the input char *
     77  * @len:  the len of @cur
     78  *
     79  * a strndup for char's to xmlChar's
     80  *
     81  * Returns a new xmlChar * or NULL
     82  */
     83 
     84 xmlChar *
     85 xmlCharStrndup(const char *cur, int len) {
     86     int i;
     87     xmlChar *ret;
     88 
     89     if ((cur == NULL) || (len < 0)) return(NULL);
     90     ret = (xmlChar *) xmlMallocAtomic((len + 1) * sizeof(xmlChar));
     91     if (ret == NULL) {
     92         xmlErrMemory(NULL, NULL);
     93         return(NULL);
     94     }
     95     for (i = 0;i < len;i++) {
     96         ret[i] = (xmlChar) cur[i];
     97         if (ret[i] == 0) return(ret);
     98     }
     99     ret[len] = 0;
    100     return(ret);
    101 }
    102 
    103 /**
    104  * xmlCharStrdup:
    105  * @cur:  the input char *
    106  *
    107  * a strdup for char's to xmlChar's
    108  *
    109  * Returns a new xmlChar * or NULL
    110  */
    111 
    112 xmlChar *
    113 xmlCharStrdup(const char *cur) {
    114     const char *p = cur;
    115 
    116     if (cur == NULL) return(NULL);
    117     while (*p != '\0') p++; /* non input consuming */
    118     return(xmlCharStrndup(cur, p - cur));
    119 }
    120 
    121 /**
    122  * xmlStrcmp:
    123  * @str1:  the first xmlChar *
    124  * @str2:  the second xmlChar *
    125  *
    126  * a strcmp for xmlChar's
    127  *
    128  * Returns the integer result of the comparison
    129  */
    130 
    131 int
    132 xmlStrcmp(const xmlChar *str1, const xmlChar *str2) {
    133     register int tmp;
    134 
    135     if (str1 == str2) return(0);
    136     if (str1 == NULL) return(-1);
    137     if (str2 == NULL) return(1);
    138     do {
    139         tmp = *str1++ - *str2;
    140         if (tmp != 0) return(tmp);
    141     } while (*str2++ != 0);
    142     return 0;
    143 }
    144 
    145 /**
    146  * xmlStrEqual:
    147  * @str1:  the first xmlChar *
    148  * @str2:  the second xmlChar *
    149  *
    150  * Check if both strings are equal of have same content.
    151  * Should be a bit more readable and faster than xmlStrcmp()
    152  *
    153  * Returns 1 if they are equal, 0 if they are different
    154  */
    155 
    156 int
    157 xmlStrEqual(const xmlChar *str1, const xmlChar *str2) {
    158     if (str1 == str2) return(1);
    159     if (str1 == NULL) return(0);
    160     if (str2 == NULL) return(0);
    161     do {
    162         if (*str1++ != *str2) return(0);
    163     } while (*str2++);
    164     return(1);
    165 }
    166 
    167 /**
    168  * xmlStrQEqual:
    169  * @pref:  the prefix of the QName
    170  * @name:  the localname of the QName
    171  * @str:  the second xmlChar *
    172  *
    173  * Check if a QName is Equal to a given string
    174  *
    175  * Returns 1 if they are equal, 0 if they are different
    176  */
    177 
    178 int
    179 xmlStrQEqual(const xmlChar *pref, const xmlChar *name, const xmlChar *str) {
    180     if (pref == NULL) return(xmlStrEqual(name, str));
    181     if (name == NULL) return(0);
    182     if (str == NULL) return(0);
    183 
    184     do {
    185         if (*pref++ != *str) return(0);
    186     } while ((*str++) && (*pref));
    187     if (*str++ != ':') return(0);
    188     do {
    189         if (*name++ != *str) return(0);
    190     } while (*str++);
    191     return(1);
    192 }
    193 
    194 /**
    195  * xmlStrncmp:
    196  * @str1:  the first xmlChar *
    197  * @str2:  the second xmlChar *
    198  * @len:  the max comparison length
    199  *
    200  * a strncmp for xmlChar's
    201  *
    202  * Returns the integer result of the comparison
    203  */
    204 
    205 int
    206 xmlStrncmp(const xmlChar *str1, const xmlChar *str2, int len) {
    207     register int tmp;
    208 
    209     if (len <= 0) return(0);
    210     if (str1 == str2) return(0);
    211     if (str1 == NULL) return(-1);
    212     if (str2 == NULL) return(1);
    213 #ifdef __GNUC__
    214     tmp = strncmp((const char *)str1, (const char *)str2, len);
    215     return tmp;
    216 #else
    217     do {
    218         tmp = *str1++ - *str2;
    219         if (tmp != 0 || --len == 0) return(tmp);
    220     } while (*str2++ != 0);
    221     return 0;
    222 #endif
    223 }
    224 
    225 static const xmlChar casemap[256] = {
    226     0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
    227     0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
    228     0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
    229     0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
    230     0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,
    231     0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,
    232     0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,
    233     0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,
    234     0x40,0x61,0x62,0x63,0x64,0x65,0x66,0x67,
    235     0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
    236     0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,
    237     0x78,0x79,0x7A,0x7B,0x5C,0x5D,0x5E,0x5F,
    238     0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,
    239     0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
    240     0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,
    241     0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,
    242     0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,
    243     0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,
    244     0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,
    245     0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,
    246     0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,
    247     0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,
    248     0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,
    249     0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,
    250     0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,
    251     0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF,
    252     0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,
    253     0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
    254     0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,
    255     0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
    256     0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,
    257     0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
    258 };
    259 
    260 /**
    261  * xmlStrcasecmp:
    262  * @str1:  the first xmlChar *
    263  * @str2:  the second xmlChar *
    264  *
    265  * a strcasecmp for xmlChar's
    266  *
    267  * Returns the integer result of the comparison
    268  */
    269 
    270 int
    271 xmlStrcasecmp(const xmlChar *str1, const xmlChar *str2) {
    272     register int tmp;
    273 
    274     if (str1 == str2) return(0);
    275     if (str1 == NULL) return(-1);
    276     if (str2 == NULL) return(1);
    277     do {
    278         tmp = casemap[*str1++] - casemap[*str2];
    279         if (tmp != 0) return(tmp);
    280     } while (*str2++ != 0);
    281     return 0;
    282 }
    283 
    284 /**
    285  * xmlStrncasecmp:
    286  * @str1:  the first xmlChar *
    287  * @str2:  the second xmlChar *
    288  * @len:  the max comparison length
    289  *
    290  * a strncasecmp for xmlChar's
    291  *
    292  * Returns the integer result of the comparison
    293  */
    294 
    295 int
    296 xmlStrncasecmp(const xmlChar *str1, const xmlChar *str2, int len) {
    297     register int tmp;
    298 
    299     if (len <= 0) return(0);
    300     if (str1 == str2) return(0);
    301     if (str1 == NULL) return(-1);
    302     if (str2 == NULL) return(1);
    303     do {
    304         tmp = casemap[*str1++] - casemap[*str2];
    305         if (tmp != 0 || --len == 0) return(tmp);
    306     } while (*str2++ != 0);
    307     return 0;
    308 }
    309 
    310 /**
    311  * xmlStrchr:
    312  * @str:  the xmlChar * array
    313  * @val:  the xmlChar to search
    314  *
    315  * a strchr for xmlChar's
    316  *
    317  * Returns the xmlChar * for the first occurrence or NULL.
    318  */
    319 
    320 const xmlChar *
    321 xmlStrchr(const xmlChar *str, xmlChar val) {
    322     if (str == NULL) return(NULL);
    323     while (*str != 0) { /* non input consuming */
    324         if (*str == val) return((xmlChar *) str);
    325         str++;
    326     }
    327     return(NULL);
    328 }
    329 
    330 /**
    331  * xmlStrstr:
    332  * @str:  the xmlChar * array (haystack)
    333  * @val:  the xmlChar to search (needle)
    334  *
    335  * a strstr for xmlChar's
    336  *
    337  * Returns the xmlChar * for the first occurrence or NULL.
    338  */
    339 
    340 const xmlChar *
    341 xmlStrstr(const xmlChar *str, const xmlChar *val) {
    342     int n;
    343 
    344     if (str == NULL) return(NULL);
    345     if (val == NULL) return(NULL);
    346     n = xmlStrlen(val);
    347 
    348     if (n == 0) return(str);
    349     while (*str != 0) { /* non input consuming */
    350         if (*str == *val) {
    351             if (!xmlStrncmp(str, val, n)) return((const xmlChar *) str);
    352         }
    353         str++;
    354     }
    355     return(NULL);
    356 }
    357 
    358 /**
    359  * xmlStrcasestr:
    360  * @str:  the xmlChar * array (haystack)
    361  * @val:  the xmlChar to search (needle)
    362  *
    363  * a case-ignoring strstr for xmlChar's
    364  *
    365  * Returns the xmlChar * for the first occurrence or NULL.
    366  */
    367 
    368 const xmlChar *
    369 xmlStrcasestr(const xmlChar *str, const xmlChar *val) {
    370     int n;
    371 
    372     if (str == NULL) return(NULL);
    373     if (val == NULL) return(NULL);
    374     n = xmlStrlen(val);
    375 
    376     if (n == 0) return(str);
    377     while (*str != 0) { /* non input consuming */
    378         if (casemap[*str] == casemap[*val])
    379             if (!xmlStrncasecmp(str, val, n)) return(str);
    380         str++;
    381     }
    382     return(NULL);
    383 }
    384 
    385 /**
    386  * xmlStrsub:
    387  * @str:  the xmlChar * array (haystack)
    388  * @start:  the index of the first char (zero based)
    389  * @len:  the length of the substring
    390  *
    391  * Extract a substring of a given string
    392  *
    393  * Returns the xmlChar * for the first occurrence or NULL.
    394  */
    395 
    396 xmlChar *
    397 xmlStrsub(const xmlChar *str, int start, int len) {
    398     int i;
    399 
    400     if (str == NULL) return(NULL);
    401     if (start < 0) return(NULL);
    402     if (len < 0) return(NULL);
    403 
    404     for (i = 0;i < start;i++) {
    405         if (*str == 0) return(NULL);
    406         str++;
    407     }
    408     if (*str == 0) return(NULL);
    409     return(xmlStrndup(str, len));
    410 }
    411 
    412 /**
    413  * xmlStrlen:
    414  * @str:  the xmlChar * array
    415  *
    416  * length of a xmlChar's string
    417  *
    418  * Returns the number of xmlChar contained in the ARRAY.
    419  */
    420 
    421 int
    422 xmlStrlen(const xmlChar *str) {
    423     int len = 0;
    424 
    425     if (str == NULL) return(0);
    426     while (*str != 0) { /* non input consuming */
    427         str++;
    428         len++;
    429     }
    430     return(len);
    431 }
    432 
    433 /**
    434  * xmlStrncat:
    435  * @cur:  the original xmlChar * array
    436  * @add:  the xmlChar * array added
    437  * @len:  the length of @add
    438  *
    439  * a strncat for array of xmlChar's, it will extend @cur with the len
    440  * first bytes of @add. Note that if @len < 0 then this is an API error
    441  * and NULL will be returned.
    442  *
    443  * Returns a new xmlChar *, the original @cur is reallocated if needed
    444  * and should not be freed
    445  */
    446 
    447 xmlChar *
    448 xmlStrncat(xmlChar *cur, const xmlChar *add, int len) {
    449     int size;
    450     xmlChar *ret;
    451 
    452     if ((add == NULL) || (len == 0))
    453         return(cur);
    454     if (len < 0)
    455 	return(NULL);
    456     if (cur == NULL)
    457         return(xmlStrndup(add, len));
    458 
    459     size = xmlStrlen(cur);
    460     if (size < 0)
    461         return(NULL);
    462     ret = (xmlChar *) xmlRealloc(cur, (size + len + 1) * sizeof(xmlChar));
    463     if (ret == NULL) {
    464         xmlErrMemory(NULL, NULL);
    465         return(cur);
    466     }
    467     memcpy(&ret[size], add, len * sizeof(xmlChar));
    468     ret[size + len] = 0;
    469     return(ret);
    470 }
    471 
    472 /**
    473  * xmlStrncatNew:
    474  * @str1:  first xmlChar string
    475  * @str2:  second xmlChar string
    476  * @len:  the len of @str2 or < 0
    477  *
    478  * same as xmlStrncat, but creates a new string.  The original
    479  * two strings are not freed. If @len is < 0 then the length
    480  * will be calculated automatically.
    481  *
    482  * Returns a new xmlChar * or NULL
    483  */
    484 xmlChar *
    485 xmlStrncatNew(const xmlChar *str1, const xmlChar *str2, int len) {
    486     int size;
    487     xmlChar *ret;
    488 
    489     if (len < 0) {
    490         len = xmlStrlen(str2);
    491         if (len < 0)
    492             return(NULL);
    493     }
    494     if ((str2 == NULL) || (len == 0))
    495         return(xmlStrdup(str1));
    496     if (str1 == NULL)
    497         return(xmlStrndup(str2, len));
    498 
    499     size = xmlStrlen(str1);
    500     if (size < 0)
    501         return(NULL);
    502     ret = (xmlChar *) xmlMalloc((size + len + 1) * sizeof(xmlChar));
    503     if (ret == NULL) {
    504         xmlErrMemory(NULL, NULL);
    505         return(xmlStrndup(str1, size));
    506     }
    507     memcpy(ret, str1, size * sizeof(xmlChar));
    508     memcpy(&ret[size], str2, len * sizeof(xmlChar));
    509     ret[size + len] = 0;
    510     return(ret);
    511 }
    512 
    513 /**
    514  * xmlStrcat:
    515  * @cur:  the original xmlChar * array
    516  * @add:  the xmlChar * array added
    517  *
    518  * a strcat for array of xmlChar's. Since they are supposed to be
    519  * encoded in UTF-8 or an encoding with 8bit based chars, we assume
    520  * a termination mark of '0'.
    521  *
    522  * Returns a new xmlChar * containing the concatenated string.
    523  */
    524 xmlChar *
    525 xmlStrcat(xmlChar *cur, const xmlChar *add) {
    526     const xmlChar *p = add;
    527 
    528     if (add == NULL) return(cur);
    529     if (cur == NULL)
    530         return(xmlStrdup(add));
    531 
    532     while (*p != 0) p++; /* non input consuming */
    533     return(xmlStrncat(cur, add, p - add));
    534 }
    535 
    536 /**
    537  * xmlStrPrintf:
    538  * @buf:   the result buffer.
    539  * @len:   the result buffer length.
    540  * @msg:   the message with printf formatting.
    541  * @...:   extra parameters for the message.
    542  *
    543  * Formats @msg and places result into @buf.
    544  *
    545  * Returns the number of characters written to @buf or -1 if an error occurs.
    546  */
    547 int XMLCDECL
    548 xmlStrPrintf(xmlChar *buf, int len, const char *msg, ...) {
    549     va_list args;
    550     int ret;
    551 
    552     if((buf == NULL) || (msg == NULL)) {
    553         return(-1);
    554     }
    555 
    556     va_start(args, msg);
    557     ret = vsnprintf((char *) buf, len, (const char *) msg, args);
    558     va_end(args);
    559     buf[len - 1] = 0; /* be safe ! */
    560 
    561     return(ret);
    562 }
    563 
    564 /**
    565  * xmlStrVPrintf:
    566  * @buf:   the result buffer.
    567  * @len:   the result buffer length.
    568  * @msg:   the message with printf formatting.
    569  * @ap:    extra parameters for the message.
    570  *
    571  * Formats @msg and places result into @buf.
    572  *
    573  * Returns the number of characters written to @buf or -1 if an error occurs.
    574  */
    575 int
    576 xmlStrVPrintf(xmlChar *buf, int len, const char *msg, va_list ap) {
    577     int ret;
    578 
    579     if((buf == NULL) || (msg == NULL)) {
    580         return(-1);
    581     }
    582 
    583     ret = vsnprintf((char *) buf, len, (const char *) msg, ap);
    584     buf[len - 1] = 0; /* be safe ! */
    585 
    586     return(ret);
    587 }
    588 
    589 /************************************************************************
    590  *                                                                      *
    591  *              Generic UTF8 handling routines                          *
    592  *                                                                      *
    593  * From rfc2044: encoding of the Unicode values on UTF-8:               *
    594  *                                                                      *
    595  * UCS-4 range (hex.)           UTF-8 octet sequence (binary)           *
    596  * 0000 0000-0000 007F   0xxxxxxx                                       *
    597  * 0000 0080-0000 07FF   110xxxxx 10xxxxxx                              *
    598  * 0000 0800-0000 FFFF   1110xxxx 10xxxxxx 10xxxxxx                     *
    599  *                                                                      *
    600  * I hope we won't use values > 0xFFFF anytime soon !                   *
    601  *                                                                      *
    602  ************************************************************************/
    603 
    604 
    605 /**
    606  * xmlUTF8Size:
    607  * @utf: pointer to the UTF8 character
    608  *
    609  * calculates the internal size of a UTF8 character
    610  *
    611  * returns the numbers of bytes in the character, -1 on format error
    612  */
    613 int
    614 xmlUTF8Size(const xmlChar *utf) {
    615     xmlChar mask;
    616     int len;
    617 
    618     if (utf == NULL)
    619         return -1;
    620     if (*utf < 0x80)
    621         return 1;
    622     /* check valid UTF8 character */
    623     if (!(*utf & 0x40))
    624         return -1;
    625     /* determine number of bytes in char */
    626     len = 2;
    627     for (mask=0x20; mask != 0; mask>>=1) {
    628         if (!(*utf & mask))
    629             return len;
    630         len++;
    631     }
    632     return -1;
    633 }
    634 
    635 /**
    636  * xmlUTF8Charcmp:
    637  * @utf1: pointer to first UTF8 char
    638  * @utf2: pointer to second UTF8 char
    639  *
    640  * compares the two UCS4 values
    641  *
    642  * returns result of the compare as with xmlStrncmp
    643  */
    644 int
    645 xmlUTF8Charcmp(const xmlChar *utf1, const xmlChar *utf2) {
    646 
    647     if (utf1 == NULL ) {
    648         if (utf2 == NULL)
    649             return 0;
    650         return -1;
    651     }
    652     return xmlStrncmp(utf1, utf2, xmlUTF8Size(utf1));
    653 }
    654 
    655 /**
    656  * xmlUTF8Strlen:
    657  * @utf:  a sequence of UTF-8 encoded bytes
    658  *
    659  * compute the length of an UTF8 string, it doesn't do a full UTF8
    660  * checking of the content of the string.
    661  *
    662  * Returns the number of characters in the string or -1 in case of error
    663  */
    664 int
    665 xmlUTF8Strlen(const xmlChar *utf) {
    666     int ret = 0;
    667 
    668     if (utf == NULL)
    669         return(-1);
    670 
    671     while (*utf != 0) {
    672         if (utf[0] & 0x80) {
    673             if ((utf[1] & 0xc0) != 0x80)
    674                 return(-1);
    675             if ((utf[0] & 0xe0) == 0xe0) {
    676                 if ((utf[2] & 0xc0) != 0x80)
    677                     return(-1);
    678                 if ((utf[0] & 0xf0) == 0xf0) {
    679                     if ((utf[0] & 0xf8) != 0xf0 || (utf[3] & 0xc0) != 0x80)
    680                         return(-1);
    681                     utf += 4;
    682                 } else {
    683                     utf += 3;
    684                 }
    685             } else {
    686                 utf += 2;
    687             }
    688         } else {
    689             utf++;
    690         }
    691         ret++;
    692     }
    693     return(ret);
    694 }
    695 
    696 /**
    697  * xmlGetUTF8Char:
    698  * @utf:  a sequence of UTF-8 encoded bytes
    699  * @len:  a pointer to the minimum number of bytes present in
    700  *        the sequence.  This is used to assure the next character
    701  *        is completely contained within the sequence.
    702  *
    703  * Read the first UTF8 character from @utf
    704  *
    705  * Returns the char value or -1 in case of error, and sets *len to
    706  *        the actual number of bytes consumed (0 in case of error)
    707  */
    708 int
    709 xmlGetUTF8Char(const unsigned char *utf, int *len) {
    710     unsigned int c;
    711 
    712     if (utf == NULL)
    713         goto error;
    714     if (len == NULL)
    715         goto error;
    716     if (*len < 1)
    717         goto error;
    718 
    719     c = utf[0];
    720     if (c & 0x80) {
    721         if (*len < 2)
    722             goto error;
    723         if ((utf[1] & 0xc0) != 0x80)
    724             goto error;
    725         if ((c & 0xe0) == 0xe0) {
    726             if (*len < 3)
    727                 goto error;
    728             if ((utf[2] & 0xc0) != 0x80)
    729                 goto error;
    730             if ((c & 0xf0) == 0xf0) {
    731                 if (*len < 4)
    732                     goto error;
    733                 if ((c & 0xf8) != 0xf0 || (utf[3] & 0xc0) != 0x80)
    734                     goto error;
    735                 *len = 4;
    736                 /* 4-byte code */
    737                 c = (utf[0] & 0x7) << 18;
    738                 c |= (utf[1] & 0x3f) << 12;
    739                 c |= (utf[2] & 0x3f) << 6;
    740                 c |= utf[3] & 0x3f;
    741             } else {
    742               /* 3-byte code */
    743                 *len = 3;
    744                 c = (utf[0] & 0xf) << 12;
    745                 c |= (utf[1] & 0x3f) << 6;
    746                 c |= utf[2] & 0x3f;
    747             }
    748         } else {
    749           /* 2-byte code */
    750             *len = 2;
    751             c = (utf[0] & 0x1f) << 6;
    752             c |= utf[1] & 0x3f;
    753         }
    754     } else {
    755         /* 1-byte code */
    756         *len = 1;
    757     }
    758     return(c);
    759 
    760 error:
    761     if (len != NULL)
    762 	*len = 0;
    763     return(-1);
    764 }
    765 
    766 /**
    767  * xmlCheckUTF8:
    768  * @utf: Pointer to putative UTF-8 encoded string.
    769  *
    770  * Checks @utf for being valid UTF-8. @utf is assumed to be
    771  * null-terminated. This function is not super-strict, as it will
    772  * allow longer UTF-8 sequences than necessary. Note that Java is
    773  * capable of producing these sequences if provoked. Also note, this
    774  * routine checks for the 4-byte maximum size, but does not check for
    775  * 0x10ffff maximum value.
    776  *
    777  * Return value: true if @utf is valid.
    778  **/
    779 int
    780 xmlCheckUTF8(const unsigned char *utf)
    781 {
    782     int ix;
    783     unsigned char c;
    784 
    785     if (utf == NULL)
    786         return(0);
    787     /*
    788      * utf is a string of 1, 2, 3 or 4 bytes.  The valid strings
    789      * are as follows (in "bit format"):
    790      *    0xxxxxxx                                      valid 1-byte
    791      *    110xxxxx 10xxxxxx                             valid 2-byte
    792      *    1110xxxx 10xxxxxx 10xxxxxx                    valid 3-byte
    793      *    11110xxx 10xxxxxx 10xxxxxx 10xxxxxx           valid 4-byte
    794      */
    795     for (ix = 0; (c = utf[ix]);) {      /* string is 0-terminated */
    796         if ((c & 0x80) == 0x00) {	/* 1-byte code, starts with 10 */
    797             ix++;
    798 	} else if ((c & 0xe0) == 0xc0) {/* 2-byte code, starts with 110 */
    799 	    if ((utf[ix+1] & 0xc0 ) != 0x80)
    800 	        return 0;
    801 	    ix += 2;
    802 	} else if ((c & 0xf0) == 0xe0) {/* 3-byte code, starts with 1110 */
    803 	    if (((utf[ix+1] & 0xc0) != 0x80) ||
    804 	        ((utf[ix+2] & 0xc0) != 0x80))
    805 		    return 0;
    806 	    ix += 3;
    807 	} else if ((c & 0xf8) == 0xf0) {/* 4-byte code, starts with 11110 */
    808 	    if (((utf[ix+1] & 0xc0) != 0x80) ||
    809 	        ((utf[ix+2] & 0xc0) != 0x80) ||
    810 		((utf[ix+3] & 0xc0) != 0x80))
    811 		    return 0;
    812 	    ix += 4;
    813 	} else				/* unknown encoding */
    814 	    return 0;
    815       }
    816       return(1);
    817 }
    818 
    819 /**
    820  * xmlUTF8Strsize:
    821  * @utf:  a sequence of UTF-8 encoded bytes
    822  * @len:  the number of characters in the array
    823  *
    824  * storage size of an UTF8 string
    825  * the behaviour is not garanteed if the input string is not UTF-8
    826  *
    827  * Returns the storage size of
    828  * the first 'len' characters of ARRAY
    829  */
    830 
    831 int
    832 xmlUTF8Strsize(const xmlChar *utf, int len) {
    833     const xmlChar   *ptr=utf;
    834     xmlChar         ch;
    835 
    836     if (utf == NULL)
    837         return(0);
    838 
    839     if (len <= 0)
    840         return(0);
    841 
    842     while ( len-- > 0) {
    843         if ( !*ptr )
    844             break;
    845         if ( (ch = *ptr++) & 0x80)
    846             while ((ch<<=1) & 0x80 ) {
    847 		if (*ptr == 0) break;
    848                 ptr++;
    849 	    }
    850     }
    851     return (ptr - utf);
    852 }
    853 
    854 
    855 /**
    856  * xmlUTF8Strndup:
    857  * @utf:  the input UTF8 *
    858  * @len:  the len of @utf (in chars)
    859  *
    860  * a strndup for array of UTF8's
    861  *
    862  * Returns a new UTF8 * or NULL
    863  */
    864 xmlChar *
    865 xmlUTF8Strndup(const xmlChar *utf, int len) {
    866     xmlChar *ret;
    867     int i;
    868 
    869     if ((utf == NULL) || (len < 0)) return(NULL);
    870     i = xmlUTF8Strsize(utf, len);
    871     ret = (xmlChar *) xmlMallocAtomic((i + 1) * sizeof(xmlChar));
    872     if (ret == NULL) {
    873         xmlGenericError(xmlGenericErrorContext,
    874                 "malloc of %ld byte failed\n",
    875                 (len + 1) * (long)sizeof(xmlChar));
    876         return(NULL);
    877     }
    878     memcpy(ret, utf, i * sizeof(xmlChar));
    879     ret[i] = 0;
    880     return(ret);
    881 }
    882 
    883 /**
    884  * xmlUTF8Strpos:
    885  * @utf:  the input UTF8 *
    886  * @pos:  the position of the desired UTF8 char (in chars)
    887  *
    888  * a function to provide the equivalent of fetching a
    889  * character from a string array
    890  *
    891  * Returns a pointer to the UTF8 character or NULL
    892  */
    893 const xmlChar *
    894 xmlUTF8Strpos(const xmlChar *utf, int pos) {
    895     xmlChar ch;
    896 
    897     if (utf == NULL) return(NULL);
    898     if (pos < 0)
    899         return(NULL);
    900     while (pos--) {
    901         if ((ch=*utf++) == 0) return(NULL);
    902         if ( ch & 0x80 ) {
    903             /* if not simple ascii, verify proper format */
    904             if ( (ch & 0xc0) != 0xc0 )
    905                 return(NULL);
    906             /* then skip over remaining bytes for this char */
    907             while ( (ch <<= 1) & 0x80 )
    908                 if ( (*utf++ & 0xc0) != 0x80 )
    909                     return(NULL);
    910         }
    911     }
    912     return((xmlChar *)utf);
    913 }
    914 
    915 /**
    916  * xmlUTF8Strloc:
    917  * @utf:  the input UTF8 *
    918  * @utfchar:  the UTF8 character to be found
    919  *
    920  * a function to provide the relative location of a UTF8 char
    921  *
    922  * Returns the relative character position of the desired char
    923  * or -1 if not found
    924  */
    925 int
    926 xmlUTF8Strloc(const xmlChar *utf, const xmlChar *utfchar) {
    927     int i, size;
    928     xmlChar ch;
    929 
    930     if (utf==NULL || utfchar==NULL) return -1;
    931     size = xmlUTF8Strsize(utfchar, 1);
    932         for(i=0; (ch=*utf) != 0; i++) {
    933             if (xmlStrncmp(utf, utfchar, size)==0)
    934                 return(i);
    935             utf++;
    936             if ( ch & 0x80 ) {
    937                 /* if not simple ascii, verify proper format */
    938                 if ( (ch & 0xc0) != 0xc0 )
    939                     return(-1);
    940                 /* then skip over remaining bytes for this char */
    941                 while ( (ch <<= 1) & 0x80 )
    942                     if ( (*utf++ & 0xc0) != 0x80 )
    943                         return(-1);
    944             }
    945         }
    946 
    947     return(-1);
    948 }
    949 /**
    950  * xmlUTF8Strsub:
    951  * @utf:  a sequence of UTF-8 encoded bytes
    952  * @start: relative pos of first char
    953  * @len:   total number to copy
    954  *
    955  * Create a substring from a given UTF-8 string
    956  * Note:  positions are given in units of UTF-8 chars
    957  *
    958  * Returns a pointer to a newly created string
    959  * or NULL if any problem
    960  */
    961 
    962 xmlChar *
    963 xmlUTF8Strsub(const xmlChar *utf, int start, int len) {
    964     int            i;
    965     xmlChar ch;
    966 
    967     if (utf == NULL) return(NULL);
    968     if (start < 0) return(NULL);
    969     if (len < 0) return(NULL);
    970 
    971     /*
    972      * Skip over any leading chars
    973      */
    974     for (i = 0;i < start;i++) {
    975         if ((ch=*utf++) == 0) return(NULL);
    976         if ( ch & 0x80 ) {
    977             /* if not simple ascii, verify proper format */
    978             if ( (ch & 0xc0) != 0xc0 )
    979                 return(NULL);
    980             /* then skip over remaining bytes for this char */
    981             while ( (ch <<= 1) & 0x80 )
    982                 if ( (*utf++ & 0xc0) != 0x80 )
    983                     return(NULL);
    984         }
    985     }
    986 
    987     return(xmlUTF8Strndup(utf, len));
    988 }
    989 
    990 /**
    991  * xmlEscapeFormatString:
    992  * @msg:  a pointer to the string in which to escape '%' characters.
    993  * Must be a heap-allocated buffer created by libxml2 that may be
    994  * returned, or that may be freed and replaced.
    995  *
    996  * Replaces the string pointed to by 'msg' with an escaped string.
    997  * Returns the same string with all '%' characters escaped.
    998  */
    999 xmlChar *
   1000 xmlEscapeFormatString(xmlChar **msg)
   1001 {
   1002     xmlChar *msgPtr = NULL;
   1003     xmlChar *result = NULL;
   1004     xmlChar *resultPtr = NULL;
   1005     size_t count = 0;
   1006     size_t msgLen = 0;
   1007     size_t resultLen = 0;
   1008 
   1009     if (!msg || !*msg)
   1010         return(NULL);
   1011 
   1012     for (msgPtr = *msg; *msgPtr != '\0'; ++msgPtr) {
   1013         ++msgLen;
   1014         if (*msgPtr == '%')
   1015             ++count;
   1016     }
   1017 
   1018     if (count == 0)
   1019         return(*msg);
   1020 
   1021     resultLen = msgLen + count + 1;
   1022     result = (xmlChar *) xmlMallocAtomic(resultLen * sizeof(xmlChar));
   1023     if (result == NULL) {
   1024         /* Clear *msg to prevent format string vulnerabilities in
   1025            out-of-memory situations. */
   1026         xmlFree(*msg);
   1027         *msg = NULL;
   1028         xmlErrMemory(NULL, NULL);
   1029         return(NULL);
   1030     }
   1031 
   1032     for (msgPtr = *msg, resultPtr = result; *msgPtr != '\0'; ++msgPtr, ++resultPtr) {
   1033         *resultPtr = *msgPtr;
   1034         if (*msgPtr == '%')
   1035             *(++resultPtr) = '%';
   1036     }
   1037     result[resultLen - 1] = '\0';
   1038 
   1039     xmlFree(*msg);
   1040     *msg = result;
   1041 
   1042     return *msg;
   1043 }
   1044 
   1045 #define bottom_xmlstring
   1046 #include "elfgcchack.h"
   1047