1 #include <string.h>

     2 #include "xmlmime.h"

     3 

     4 static const char *

     5 getTok(const char **pp)

     6 {

     7   /* inComment means one level of nesting; inComment+1 means two levels etc */

     8   enum { inAtom, inString, init, inComment };

     9   int state = init;

    10   const char *tokStart = 0;

    11   for (;;) {

    12     switch (**pp) {

    13     case '\0':

    14       if (state == inAtom)

    15         return tokStart;

    16       return 0;

    17     case ' ':

    18     case '\r':

    19     case '\t':

    20     case '\n':

    21       if (state == inAtom)

    22         return tokStart;

    23       break;

    24     case '(':

    25       if (state == inAtom)

    26         return tokStart;

    27       if (state != inString)

    28         state++;

    29       break;

    30     case ')':

    31       if (state > init)

    32         --state;

    33       else if (state != inString)

    34         return 0;

    35       break;

    36     case ';':

    37     case '/':

    38     case '=':

    39       if (state == inAtom)

    40         return tokStart;

    41       if (state == init)

    42         return (*pp)++;

    43       break;

    44     case '\\':

    45       ++*pp;

    46       if (**pp == '\0')

    47         return 0;

    48       break;

    49     case '"':

    50       switch (state) {

    51       case inString:

    52         ++*pp;

    53         return tokStart;

    54       case inAtom:

    55         return tokStart;

    56       case init:

    57         tokStart = *pp;

    58         state = inString;

    59         break;

    60       }

    61       break;

    62     default:

    63       if (state == init) {

    64         tokStart = *pp;

    65         state = inAtom;

    66       }

    67       break;

    68     }

    69     ++*pp;

    70   }

    71   /* not reached */

    72 }

    73 

    74 /* key must be lowercase ASCII */

    75 

    76 static int

    77 matchkey(const char *start, const char *end, const char *key)

    78 {

    79   if (!start)

    80     return 0;

    81   for (; start != end; start++, key++)

    82     if (*start != *key && *start != 'A' + (*key - 'a'))

    83       return 0;

    84   return *key == '\0';

    85 }

    86 

    87 void

    88 getXMLCharset(const char *buf, char *charset)

    89 {

    90   const char *next, *p;

    91 

    92   charset[0] = '\0';

    93   next = buf;

    94   p = getTok(&next);

    95   if (matchkey(p, next, "text"))

    96     strcpy(charset, "us-ascii");

    97   else if (!matchkey(p, next, "application"))

    98     return;

    99   p = getTok(&next);

   100   if (!p || *p != '/')

   101     return;

   102   p = getTok(&next);

   103 #if 0

   104   if (!matchkey(p, next, "xml") && charset[0] == '\0')

   105     return;

   106 #endif

   107   p = getTok(&next);

   108   while (p) {

   109     if (*p == ';') {

   110       p = getTok(&next);

   111       if (matchkey(p, next, "charset")) {

   112         p = getTok(&next);

   113         if (p && *p == '=') {

   114           p = getTok(&next);

   115           if (p) {

   116             char *s = charset;

   117             if (*p == '"') {

   118               while (++p != next - 1) {

   119                 if (*p == '\\')

   120                   ++p;

   121                 if (s == charset + CHARSET_MAX - 1) {

   122                   charset[0] = '\0';

   123                   break;

   124                 }

   125                 *s++ = *p;

   126               }

   127               *s++ = '\0';

   128             }

   129             else {

   130               if (next - p > CHARSET_MAX - 1)

   131                 break;

   132               while (p != next)

   133                 *s++ = *p++;

   134               *s = 0;

   135               break;

   136             }

   137           }

   138         }

   139         break;

   140       }

   141     }

   142   else

   143     p = getTok(&next);

   144   }

   145 }

   146 

   147 #ifdef TEST

   148 

   149 #include <stdio.h>

   150 

   151 int

   152 main(int argc, char *argv[])

   153 {

   154   char buf[CHARSET_MAX];

   155   if (argc <= 1)

   156     return 1;

   157   printf("%s\n", argv[1]);

   158   getXMLCharset(argv[1], buf);

   159   printf("charset=\"%s\"\n", buf);

   160   return 0;

   161 }

   162 

   163 #endif /* TEST */