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

     2    See the file COPYING for copying permission.

     3 */

     4 #include <string.h>

     5 #include "xmlmime.h"

     6 

     7 static const char *

     8 getTok(const char **pp)

     9 {

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

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

    12   int state = init;

    13   const char *tokStart = 0;

    14   for (;;) {

    15     switch (**pp) {

    16     case '\0':

    17       if (state == inAtom)

    18         return tokStart;

    19       return 0;

    20     case ' ':

    21     case '\r':

    22     case '\t':

    23     case '\n':

    24       if (state == inAtom)

    25         return tokStart;

    26       break;

    27     case '(':

    28       if (state == inAtom)

    29         return tokStart;

    30       if (state != inString)

    31         state++;

    32       break;

    33     case ')':

    34       if (state > init)

    35         --state;

    36       else if (state != inString)

    37         return 0;

    38       break;

    39     case ';':

    40     case '/':

    41     case '=':

    42       if (state == inAtom)

    43         return tokStart;

    44       if (state == init)

    45         return (*pp)++;

    46       break;

    47     case '\\':

    48       ++*pp;

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

    50         return 0;

    51       break;

    52     case '"':

    53       switch (state) {

    54       case inString:

    55         ++*pp;

    56         return tokStart;

    57       case inAtom:

    58         return tokStart;

    59       case init:

    60         tokStart = *pp;

    61         state = inString;

    62         break;

    63       }

    64       break;

    65     default:

    66       if (state == init) {

    67         tokStart = *pp;

    68         state = inAtom;

    69       }

    70       break;

    71     }

    72     ++*pp;

    73   }

    74   /* not reached */

    75 }

    76 

    77 /* key must be lowercase ASCII */

    78 

    79 static int

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

    81 {

    82   if (!start)

    83     return 0;

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

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

    86       return 0;

    87   return *key == '\0';

    88 }

    89 

    90 void

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

    92 {

    93   const char *next, *p;

    94 

    95   charset[0] = '\0';

    96   next = buf;

    97   p = getTok(&next);

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

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

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

   101     return;

   102   p = getTok(&next);

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

   104     return;

   105   p = getTok(&next);

   106 #if 0

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

   108     return;

   109 #endif

   110   p = getTok(&next);

   111   while (p) {

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

   113       p = getTok(&next);

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

   115         p = getTok(&next);

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

   117           p = getTok(&next);

   118           if (p) {

   119             char *s = charset;

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

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

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

   123                   ++p;

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

   125                   charset[0] = '\0';

   126                   break;

   127                 }

   128                 *s++ = *p;

   129               }

   130               *s++ = '\0';

   131             }

   132             else {

   133               if (next - p > CHARSET_MAX - 1)

   134                 break;

   135               while (p != next)

   136                 *s++ = *p++;

   137               *s = 0;

   138               break;

   139             }

   140           }

   141         }

   142         break;

   143       }

   144     }

   145   else

   146     p = getTok(&next);

   147   }

   148 }

   149 

   150 #ifdef TEST

   151 

   152 #include <stdio.h>

   153 

   154 int

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

   156 {

   157   char buf[CHARSET_MAX];

   158   if (argc <= 1)

   159     return 1;

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

   161   getXMLCharset(argv[1], buf);

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

   163   return 0;

   164 }

   165 

   166 #endif /* TEST */