1 /* Copyright (c) 1998, 1999 Thai Open Source Software Center Ltd

     2    See the file COPYING for copying permission.

     3 */

     4 #define CHARSET_MAX 41

     5 

     6 static const char *

     7 getTok(const char **pp)

     8 {

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

    10   int state = init;

    11   const char *tokStart = 0;

    12   for (;;) {

    13     switch (**pp) {

    14     case '\0':

    15       return 0;

    16     case ' ':

    17     case '\r':

    18     case '\t':

    19     case '\n':

    20       if (state == inAtom)

    21         return tokStart;

    22       break;

    23     case '(':

    24       if (state == inAtom)

    25         return tokStart;

    26       if (state != inString)

    27         state++;

    28       break;

    29     case ')':

    30       if (state > init)

    31         --state;

    32       else if (state != inString)

    33         return 0;

    34       break;

    35     case ';':

    36     case '/':

    37     case '=':

    38       if (state == inAtom)

    39         return tokStart;

    40       if (state == init)

    41         return (*pp)++;

    42       break;

    43     case '\\':

    44       ++*pp;

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

    46         return 0;

    47       break;

    48     case '"':

    49       switch (state) {

    50       case inString:

    51         ++*pp;

    52         return tokStart;

    53       case inAtom:

    54         return tokStart;

    55       case init:

    56         tokStart = *pp;

    57         state = inString;

    58         break;

    59       }

    60       break;

    61     default:

    62       if (state == init) {

    63         tokStart = *pp;

    64         state = inAtom;

    65       }

    66       break;

    67     }

    68     ++*pp;

    69   }

    70   /* not reached */

    71 }

    72 

    73 /* key must be lowercase ASCII */

    74 

    75 static int

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

    77 {

    78   if (!start)

    79     return 0;

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

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

    82       return 0;

    83   return *key == '\0';

    84 }

    85 

    86 void

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

    88 {

    89   const char *next, *p;

    90 

    91   charset[0] = '\0';

    92   next = buf;

    93   p = getTok(&next);

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

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

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

    97     return;

    98   p = getTok(&next);

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

   100     return;

   101   p = getTok(&next);

   102   if (matchkey(p, next, "xml"))

   103     isXml = 1;

   104   p = getTok(&next);

   105   while (p) {

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

   107       p = getTok(&next);

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

   109         p = getTok(&next);

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

   111           p = getTok(&next);

   112           if (p) {

   113             char *s = charset;

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

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

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

   117                   ++p;

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

   119                   charset[0] = '\0';

   120                   break;

   121                 }

   122                 *s++ = *p;

   123               }

   124               *s++ = '\0';

   125             }

   126             else {

   127               if (next - p > CHARSET_MAX - 1)

   128                 break;

   129               while (p != next)

   130                 *s++ = *p++;

   131               *s = 0;

   132               break;

   133             }

   134           }

   135         }

   136       }

   137     }

   138   else

   139     p = getTok(&next);

   140   }

   141 }

   142 

   143 int

   144 main(int argc, char **argv)

   145 {

   146   char buf[CHARSET_MAX];

   147   getXMLCharset(argv[1], buf);

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

   149   return 0;

   150 }