1 /*
2  * Summary: interface for the encoding conversion functions
3  * Description: interface for the encoding conversion functions needed for
4  *              XML basic encoding and iconv() support.
5  *
6  * Related specs are
7  * rfc2044        (UTF-8 and UTF-16) F. Yergeau Alis Technologies
8  * [ISO-10646]    UTF-8 and UTF-16 in Annexes
9  * [ISO-8859-1]   ISO Latin-1 characters codes.
10  * [UNICODE]      The Unicode Consortium, "The Unicode Standard --
11  *                Worldwide Character Encoding -- Version 1.0", Addison-
12  *                Wesley, Volume 1, 1991, Volume 2, 1992.  UTF-8 is
13  *                described in Unicode Technical Report #4.
14  * [US-ASCII]     Coded Character Set--7-bit American Standard Code for
15  *                Information Interchange, ANSI X3.4-1986.
16  *
17  * Copy: See Copyright for the status of this software.
18  *
19  * Author: Daniel Veillard
20  */
21 
22 #ifndef __XML_CHAR_ENCODING_H__
23 #define __XML_CHAR_ENCODING_H__
24 
25 #include <libxml/xmlversion.h>
26 
27 #ifdef LIBXML_ICONV_ENABLED
28 #include <iconv.h>
29 #endif
30 
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34 
35 /*
36  * xmlCharEncoding:
37  *
38  * Predefined values for some standard encodings.
39  * Libxml does not do beforehand translation on UTF8 and ISOLatinX.
40  * It also supports ASCII, ISO-8859-1, and UTF16 (LE and BE) by default.
41  *
42  * Anything else would have to be translated to UTF8 before being
43  * given to the parser itself. The BOM for UTF16 and the encoding
44  * declaration are looked at and a converter is looked for at that
45  * point. If not found the parser stops here as asked by the XML REC. A
46  * converter can be registered by the user using xmlRegisterCharEncodingHandler
47  * but the current form doesn't allow stateful transcoding (a serious
48  * problem agreed !). If iconv has been found it will be used
49  * automatically and allow stateful transcoding, the simplest is then
50  * to be sure to enable iconv and to provide iconv libs for the encoding
51  * support needed.
52  *
53  * Note that the generic "UTF-16" is not a predefined value.  Instead, only
54  * the specific UTF-16LE and UTF-16BE are present.
55  */
56 typedef enum {
57     XML_CHAR_ENCODING_ERROR=   -1, /* No char encoding detected */
58     XML_CHAR_ENCODING_NONE=	0, /* No char encoding detected */
59     XML_CHAR_ENCODING_UTF8=	1, /* UTF-8 */
60     XML_CHAR_ENCODING_UTF16LE=	2, /* UTF-16 little endian */
61     XML_CHAR_ENCODING_UTF16BE=	3, /* UTF-16 big endian */
62     XML_CHAR_ENCODING_UCS4LE=	4, /* UCS-4 little endian */
63     XML_CHAR_ENCODING_UCS4BE=	5, /* UCS-4 big endian */
64     XML_CHAR_ENCODING_EBCDIC=	6, /* EBCDIC uh! */
65     XML_CHAR_ENCODING_UCS4_2143=7, /* UCS-4 unusual ordering */
66     XML_CHAR_ENCODING_UCS4_3412=8, /* UCS-4 unusual ordering */
67     XML_CHAR_ENCODING_UCS2=	9, /* UCS-2 */
68     XML_CHAR_ENCODING_8859_1=	10,/* ISO-8859-1 ISO Latin 1 */
69     XML_CHAR_ENCODING_8859_2=	11,/* ISO-8859-2 ISO Latin 2 */
70     XML_CHAR_ENCODING_8859_3=	12,/* ISO-8859-3 */
71     XML_CHAR_ENCODING_8859_4=	13,/* ISO-8859-4 */
72     XML_CHAR_ENCODING_8859_5=	14,/* ISO-8859-5 */
73     XML_CHAR_ENCODING_8859_6=	15,/* ISO-8859-6 */
74     XML_CHAR_ENCODING_8859_7=	16,/* ISO-8859-7 */
75     XML_CHAR_ENCODING_8859_8=	17,/* ISO-8859-8 */
76     XML_CHAR_ENCODING_8859_9=	18,/* ISO-8859-9 */
77     XML_CHAR_ENCODING_2022_JP=  19,/* ISO-2022-JP */
78     XML_CHAR_ENCODING_SHIFT_JIS=20,/* Shift_JIS */
79     XML_CHAR_ENCODING_EUC_JP=   21,/* EUC-JP */
80     XML_CHAR_ENCODING_ASCII=    22 /* pure ASCII */
81 } xmlCharEncoding;
82 
83 /**
84  * xmlCharEncodingInputFunc:
85  * @out:  a pointer to an array of bytes to store the UTF-8 result
86  * @outlen:  the length of @out
87  * @in:  a pointer to an array of chars in the original encoding
88  * @inlen:  the length of @in
89  *
90  * Take a block of chars in the original encoding and try to convert
91  * it to an UTF-8 block of chars out.
92  *
93  * Returns the number of bytes written, -1 if lack of space, or -2
94  *     if the transcoding failed.
95  * The value of @inlen after return is the number of octets consumed
96  *     if the return value is positive, else unpredictiable.
97  * The value of @outlen after return is the number of octets consumed.
98  */
99 typedef int (* xmlCharEncodingInputFunc)(unsigned char *out, int *outlen,
100                                          const unsigned char *in, int *inlen);
101 
102 
103 /**
104  * xmlCharEncodingOutputFunc:
105  * @out:  a pointer to an array of bytes to store the result
106  * @outlen:  the length of @out
107  * @in:  a pointer to an array of UTF-8 chars
108  * @inlen:  the length of @in
109  *
110  * Take a block of UTF-8 chars in and try to convert it to another
111  * encoding.
112  * Note: a first call designed to produce heading info is called with
113  * in = NULL. If stateful this should also initialize the encoder state.
114  *
115  * Returns the number of bytes written, -1 if lack of space, or -2
116  *     if the transcoding failed.
117  * The value of @inlen after return is the number of octets consumed
118  *     if the return value is positive, else unpredictiable.
119  * The value of @outlen after return is the number of octets produced.
120  */
121 typedef int (* xmlCharEncodingOutputFunc)(unsigned char *out, int *outlen,
122                                           const unsigned char *in, int *inlen);
123 
124 
125 /*
126  * Block defining the handlers for non UTF-8 encodings.
127  * If iconv is supported, there are two extra fields.
128  */
129 typedef struct _xmlCharEncodingHandler xmlCharEncodingHandler;
130 typedef xmlCharEncodingHandler *xmlCharEncodingHandlerPtr;
131 struct _xmlCharEncodingHandler {
132     char                       *name;
133     xmlCharEncodingInputFunc   input;
134     xmlCharEncodingOutputFunc  output;
135 #ifdef LIBXML_ICONV_ENABLED
136     iconv_t                    iconv_in;
137     iconv_t                    iconv_out;
138 #endif /* LIBXML_ICONV_ENABLED */
139 #ifdef LIBXML_ICU_ENABLED
140     struct _uconv_t            *uconv_in;
141     struct _uconv_t            *uconv_out;
142 #endif /* LIBXML_ICU_ENABLED */
143 };
144 
145 #ifdef __cplusplus
146 }
147 #endif
148 #include <libxml/tree.h>
149 #ifdef __cplusplus
150 extern "C" {
151 #endif
152 
153 /*
154  * Interfaces for encoding handlers.
155  */
156 XML_DEPRECATED
157 XMLPUBFUN void XMLCALL
158 	xmlInitCharEncodingHandlers	(void);
159 XML_DEPRECATED
160 XMLPUBFUN void XMLCALL
161 	xmlCleanupCharEncodingHandlers	(void);
162 XMLPUBFUN void XMLCALL
163 	xmlRegisterCharEncodingHandler	(xmlCharEncodingHandlerPtr handler);
164 XMLPUBFUN xmlCharEncodingHandlerPtr XMLCALL
165 	xmlGetCharEncodingHandler	(xmlCharEncoding enc);
166 XMLPUBFUN xmlCharEncodingHandlerPtr XMLCALL
167 	xmlFindCharEncodingHandler	(const char *name);
168 XMLPUBFUN xmlCharEncodingHandlerPtr XMLCALL
169 	xmlNewCharEncodingHandler	(const char *name,
170 					 xmlCharEncodingInputFunc input,
171 					 xmlCharEncodingOutputFunc output);
172 
173 /*
174  * Interfaces for encoding names and aliases.
175  */
176 XMLPUBFUN int XMLCALL
177 	xmlAddEncodingAlias		(const char *name,
178 					 const char *alias);
179 XMLPUBFUN int XMLCALL
180 	xmlDelEncodingAlias		(const char *alias);
181 XMLPUBFUN const char * XMLCALL
182 	xmlGetEncodingAlias		(const char *alias);
183 XMLPUBFUN void XMLCALL
184 	xmlCleanupEncodingAliases	(void);
185 XMLPUBFUN xmlCharEncoding XMLCALL
186 	xmlParseCharEncoding		(const char *name);
187 XMLPUBFUN const char * XMLCALL
188 	xmlGetCharEncodingName		(xmlCharEncoding enc);
189 
190 /*
191  * Interfaces directly used by the parsers.
192  */
193 XMLPUBFUN xmlCharEncoding XMLCALL
194 	xmlDetectCharEncoding		(const unsigned char *in,
195 					 int len);
196 
197 XMLPUBFUN int XMLCALL
198 	xmlCharEncOutFunc		(xmlCharEncodingHandler *handler,
199 					 xmlBufferPtr out,
200 					 xmlBufferPtr in);
201 
202 XMLPUBFUN int XMLCALL
203 	xmlCharEncInFunc		(xmlCharEncodingHandler *handler,
204 					 xmlBufferPtr out,
205 					 xmlBufferPtr in);
206 XMLPUBFUN int XMLCALL
207 	xmlCharEncFirstLine		(xmlCharEncodingHandler *handler,
208 					 xmlBufferPtr out,
209 					 xmlBufferPtr in);
210 XMLPUBFUN int XMLCALL
211 	xmlCharEncCloseFunc		(xmlCharEncodingHandler *handler);
212 
213 /*
214  * Export a few useful functions
215  */
216 #ifdef LIBXML_OUTPUT_ENABLED
217 XMLPUBFUN int XMLCALL
218 	UTF8Toisolat1			(unsigned char *out,
219 					 int *outlen,
220 					 const unsigned char *in,
221 					 int *inlen);
222 #endif /* LIBXML_OUTPUT_ENABLED */
223 XMLPUBFUN int XMLCALL
224 	isolat1ToUTF8			(unsigned char *out,
225 					 int *outlen,
226 					 const unsigned char *in,
227 					 int *inlen);
228 #ifdef __cplusplus
229 }
230 #endif
231 
232 #endif /* __XML_CHAR_ENCODING_H__ */
233