xref: /freebsd/contrib/expat/xmlwf/ct.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
1 /*
2                             __  __            _
3                          ___\ \/ /_ __   __ _| |_
4                         / _ \\  /| '_ \ / _` | __|
5                        |  __//  \| |_) | (_| | |_
6                         \___/_/\_\ .__/ \__,_|\__|
7                                  |_| XML parser
8 
9    Copyright (c) 1997-2000 Thai Open Source Software Center Ltd
10    Copyright (c) 2002      Fred L. Drake, Jr. <fdrake@users.sourceforge.net>
11    Copyright (c) 2016-2017 Sebastian Pipping <sebastian@pipping.org>
12    Licensed under the MIT license:
13 
14    Permission is  hereby granted,  free of charge,  to any  person obtaining
15    a  copy  of  this  software   and  associated  documentation  files  (the
16    "Software"),  to  deal in  the  Software  without restriction,  including
17    without  limitation the  rights  to use,  copy,  modify, merge,  publish,
18    distribute, sublicense, and/or sell copies of the Software, and to permit
19    persons  to whom  the Software  is  furnished to  do so,  subject to  the
20    following conditions:
21 
22    The above copyright  notice and this permission notice  shall be included
23    in all copies or substantial portions of the Software.
24 
25    THE  SOFTWARE  IS  PROVIDED  "AS  IS",  WITHOUT  WARRANTY  OF  ANY  KIND,
26    EXPRESS  OR IMPLIED,  INCLUDING  BUT  NOT LIMITED  TO  THE WARRANTIES  OF
27    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
28    NO EVENT SHALL THE AUTHORS OR  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
29    DAMAGES OR  OTHER LIABILITY, WHETHER  IN AN  ACTION OF CONTRACT,  TORT OR
30    OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
31    USE OR OTHER DEALINGS IN THE SOFTWARE.
32 */
33 
34 #define CHARSET_MAX 41
35 
36 static const char *
37 getTok(const char **pp) {
38   enum { inAtom, inString, init, inComment };
39   int state = init;
40   const char *tokStart = 0;
41   for (;;) {
42     switch (**pp) {
43     case '\0':
44       return 0;
45     case ' ':
46     case '\r':
47     case '\t':
48     case '\n':
49       if (state == inAtom)
50         return tokStart;
51       break;
52     case '(':
53       if (state == inAtom)
54         return tokStart;
55       if (state != inString)
56         state++;
57       break;
58     case ')':
59       if (state > init)
60         --state;
61       else if (state != inString)
62         return 0;
63       break;
64     case ';':
65     case '/':
66     case '=':
67       if (state == inAtom)
68         return tokStart;
69       if (state == init)
70         return (*pp)++;
71       break;
72     case '\\':
73       ++*pp;
74       if (**pp == '\0')
75         return 0;
76       break;
77     case '"':
78       switch (state) {
79       case inString:
80         ++*pp;
81         return tokStart;
82       case inAtom:
83         return tokStart;
84       case init:
85         tokStart = *pp;
86         state = inString;
87         break;
88       }
89       break;
90     default:
91       if (state == init) {
92         tokStart = *pp;
93         state = inAtom;
94       }
95       break;
96     }
97     ++*pp;
98   }
99   /* not reached */
100 }
101 
102 /* key must be lowercase ASCII */
103 
104 static int
105 matchkey(const char *start, const char *end, const char *key) {
106   if (! start)
107     return 0;
108   for (; start != end; start++, key++)
109     if (*start != *key && *start != 'A' + (*key - 'a'))
110       return 0;
111   return *key == '\0';
112 }
113 
114 void
115 getXMLCharset(const char *buf, char *charset) {
116   const char *next, *p;
117 
118   charset[0] = '\0';
119   next = buf;
120   p = getTok(&next);
121   if (matchkey(p, next, "text"))
122     strcpy(charset, "us-ascii");
123   else if (! matchkey(p, next, "application"))
124     return;
125   p = getTok(&next);
126   if (! p || *p != '/')
127     return;
128   p = getTok(&next);
129   if (matchkey(p, next, "xml"))
130     isXml = 1;
131   p = getTok(&next);
132   while (p) {
133     if (*p == ';') {
134       p = getTok(&next);
135       if (matchkey(p, next, "charset")) {
136         p = getTok(&next);
137         if (p && *p == '=') {
138           p = getTok(&next);
139           if (p) {
140             char *s = charset;
141             if (*p == '"') {
142               while (++p != next - 1) {
143                 if (*p == '\\')
144                   ++p;
145                 if (s == charset + CHARSET_MAX - 1) {
146                   charset[0] = '\0';
147                   break;
148                 }
149                 *s++ = *p;
150               }
151               *s++ = '\0';
152             } else {
153               if (next - p > CHARSET_MAX - 1)
154                 break;
155               while (p != next)
156                 *s++ = *p++;
157               *s = 0;
158               break;
159             }
160           }
161         }
162       }
163     } else
164       p = getTok(&next);
165   }
166 }
167 
168 int
169 main(int argc, char **argv) {
170   char buf[CHARSET_MAX];
171   getXMLCharset(argv[1], buf);
172   printf("charset = \"%s\"\n", buf);
173   return 0;
174 }
175