Annotation of XML/encoding.c, revision 1.7
1.1 daniel 1: /*
2: * encoding.c : implements the encoding conversion functions needed for XML
3: *
4: * Related specs:
5: * rfc2044 (UTF-8 and UTF-16) F. Yergeau Alis Technologies
6: * [ISO-10646] UTF-8 and UTF-16 in Annexes
7: * [ISO-8859-1] ISO Latin-1 characters codes.
8: * [UNICODE] The Unicode Consortium, "The Unicode Standard --
9: * Worldwide Character Encoding -- Version 1.0", Addison-
10: * Wesley, Volume 1, 1991, Volume 2, 1992. UTF-8 is
11: * described in Unicode Technical Report #4.
12: * [US-ASCII] Coded Character Set--7-bit American Standard Code for
13: * Information Interchange, ANSI X3.4-1986.
14: *
15: * Original code from "Martin J. Duerst" <duerst@w3.org>
16: *
17: * See Copyright for the status of this software.
18: *
19: * Daniel.Veillard@w3.org
20: */
21:
1.7 ! daniel 22: #include <ctype.h>
1.1 daniel 23: #include "encoding.h"
1.3 daniel 24:
25: /*
26: * From rfc2044: encoding of the Unicode values on UTF-8:
27: *
28: * UCS-4 range (hex.) UTF-8 octet sequence (binary)
29: * 0000 0000-0000 007F 0xxxxxxx
30: * 0000 0080-0000 07FF 110xxxxx 10xxxxxx
31: * 0000 0800-0000 FFFF 1110xxxx 10xxxxxx 10xxxxxx
32: *
33: * I hope we won't use values > 0xFFFF anytime soon !
34: */
1.1 daniel 35:
36: /**
37: * isolat1ToUTF8:
38: * @out: a pointer ot an array of bytes to store the result
39: * @outlen: the lenght of @out
40: * @in: a pointer ot an array of ISO Latin 1 chars
41: * @inlen: the lenght of @in
42: *
43: * Take a block of ISO Latin 1 chars in and try to convert it to an UTF-8
44: * block of chars out.
1.6 daniel 45: * Returns the number of byte written, or -1 by lack of space.
1.1 daniel 46: */
47: int
48: isolat1ToUTF8(unsigned char* out, int outlen, unsigned char* in, int inlen)
49: {
50: unsigned char* outstart= out;
51: unsigned char* outend= out+outlen;
52: unsigned char* inend= in+inlen;
53: unsigned char c;
54:
55: while (in < inend) {
56: c= *in++;
57: if (c < 0x80) {
58: if (out >= outend) return -1;
59: *out++ = c;
60: }
61: else {
62: if (out >= outend) return -1;
63: *out++ = 0xC0 | (c >> 6);
64: if (out >= outend) return -1;
65: *out++ = 0x80 | (0x3F & c);
66: }
67: }
68: return out-outstart;
69: }
70:
71: /**
72: * UTF8Toisolat1:
73: * @out: a pointer ot an array of bytes to store the result
74: * @outlen: the lenght of @out
75: * @in: a pointer ot an array of UTF-8 chars
76: * @inlen: the lenght of @in
77: *
78: * Take a block of UTF-8 chars in and try to convert it to an ISO Latin 1
79: * block of chars out.
80: * TODO: need a fallback mechanism ...
1.6 daniel 81: * Returns the number of byte written, or -1 by lack of space, or -2
1.1 daniel 82: * if the transcoding failed.
83: */
84: int
85: UTF8Toisolat1(unsigned char* out, int outlen, unsigned char* in, int inlen)
86: {
87: unsigned char* outstart= out;
88: unsigned char* outend= out+outlen;
89: unsigned char* inend= in+inlen;
90: unsigned char c;
91:
92: while (in < inend) {
93: c= *in++;
94: if (c < 0x80) {
95: if (out >= outend) return -1;
96: *out++= c;
97: }
98: else if (((c & 0xFE) == 0xC2) && in<inend) {
99: if (out >= outend) return -1;
100: *out++= ((c & 0x03) << 6) | (*in++ & 0x3F);
101: }
102: else return -2;
103: }
104: return out-outstart;
105: }
106:
107: /**
108: * UTF16ToUTF8:
109: * @out: a pointer ot an array of bytes to store the result
110: * @outlen: the lenght of @out
111: * @in: a pointer ot an array of UTF-16 chars (array of unsigned shorts)
112: * @inlen: the lenght of @in
113: *
114: * Take a block of UTF-16 ushorts in and try to convert it to an UTF-8
115: * block of chars out.
1.6 daniel 116: * Returns the number of byte written, or -1 by lack of space.
1.1 daniel 117: */
118: int
119: UTF16ToUTF8(unsigned char* out, int outlen, unsigned short* in, int inlen)
120: {
121: unsigned char* outstart= out;
122: unsigned char* outend= out+outlen;
123: unsigned short* inend= in+inlen;
124: unsigned int c, d;
125: int bits;
126:
127: while (in < inend) {
128: c= *in++;
129: if ((c & 0xFC00) == 0xD800) { /* surrogates */
130: if ((in<inend) && (((d=*in++) & 0xFC00) == 0xDC00)) {
131: c &= 0x03FF;
132: c <<= 10;
133: c |= d & 0x03FF;
134: c += 0x10000;
135: }
136: else return -1;
137: }
138:
139: /* assertion: c is a single UTF-4 value */
140:
141: if (out >= outend) return -1;
142: if (c < 0x80) { *out++= c; bits= -6; }
143: else if (c < 0x800) { *out++= (c >> 6) | 0xC0; bits= 0; }
144: else if (c < 0x10000) { *out++= (c >> 12) | 0xE0; bits= 6; }
145: else { *out++= (c >> 18) | 0xF0; bits= 12; }
146:
147: for ( ; bits < 0; bits-= 6) {
148: if (out >= outend) return -1;
149: *out++= (c >> bits) & 0x3F;
150: }
151: }
152: return out-outstart;
153: }
154:
155: /**
156: * UTF8ToUTF16:
157: * @out: a pointer ot an array of shorts to store the result
158: * @outlen: the lenght of @out (number of shorts)
159: * @in: a pointer ot an array of UTF-8 chars
160: * @inlen: the lenght of @in
161: *
162: * Take a block of UTF-8 chars in and try to convert it to an UTF-16
163: * block of chars out.
164: * TODO: need a fallback mechanism ...
1.6 daniel 165: * Returns the number of byte written, or -1 by lack of space, or -2
1.1 daniel 166: * if the transcoding failed.
167: */
168: int
169: UTF8ToUTF16(unsigned short* out, int outlen, unsigned char* in, int inlen)
170: {
171: unsigned short* outstart= out;
172: unsigned short* outend= out+outlen;
173: unsigned char* inend= in+inlen;
174: unsigned int c, d, trailing;
175:
176: while (in < inend) {
177: d= *in++;
178: if (d < 0x80) { c= d; trailing= 0; }
179: else if (d < 0xC0) return -2; /* trailing byte in leading position */
180: else if (d < 0xE0) { c= d & 0x1F; trailing= 1; }
181: else if (d < 0xF0) { c= d & 0x0F; trailing= 2; }
182: else if (d < 0xF8) { c= d & 0x07; trailing= 3; }
183: else return -2; /* no chance for this in UTF-16 */
184:
185: for ( ; trailing; trailing--) {
186: if ((in >= inend) || (((d= *in++) & 0xC0) != 0x80)) return -1;
187: c <<= 6;
188: c |= d & 0x3F;
189: }
190:
191: /* assertion: c is a single UTF-4 value */
192: if (c < 0x10000) {
193: if (out >= outend) return -1;
194: *out++ = c;
195: }
196: else if (c < 0x110000) {
197: if (out+1 >= outend) return -1;
198: c -= 0x10000;
199: *out++ = 0xD800 | (c >> 10);
200: *out++ = 0xDC00 | (c & 0x03FF);
201: }
202: else return -1;
203: }
204: return out-outstart;
205: }
206:
207:
1.7 ! daniel 208: /**
! 209: * xmlDetectCharEncoding:
! 210: * @in: a pointer to the first bytes of the XML entity, must be at least
! 211: * 4 bytes long.
! 212: *
! 213: * Guess the encoding of the entity using the first bytes of the entity content
! 214: * accordingly of the non-normative appendix F of the XML-1.0 recommendation.
! 215: *
! 216: * Returns one of the XML_CHAR_ENCODING_... values.
! 217: */
! 218: xmlCharEncoding
! 219: xmlDetectCharEncoding(unsigned char* in)
! 220: {
! 221: if ((in[0] == 0x00) && (in[1] == 0x00) &&
! 222: (in[2] == 0x00) && (in[3] == 0x3C))
! 223: return(XML_CHAR_ENCODING_UCS4BE);
! 224: if ((in[0] == 0x3C) && (in[1] == 0x00) &&
! 225: (in[2] == 0x00) && (in[3] == 0x00))
! 226: return(XML_CHAR_ENCODING_UCS4LE);
! 227: if ((in[0] == 0x00) && (in[1] == 0x00) &&
! 228: (in[2] == 0x3C) && (in[3] == 0x00))
! 229: return(XML_CHAR_ENCODING_UCS4_2143);
! 230: if ((in[0] == 0x00) && (in[1] == 0x3C) &&
! 231: (in[2] == 0x00) && (in[3] == 0x00))
! 232: return(XML_CHAR_ENCODING_UCS4_3412);
! 233: if ((in[0] == 0xFE) && (in[1] == 0xFF))
! 234: return(XML_CHAR_ENCODING_UTF16BE);
! 235: if ((in[0] == 0xFF) && (in[1] == 0xFE))
! 236: return(XML_CHAR_ENCODING_UTF16LE);
! 237: if ((in[0] == 0x4C) && (in[1] == 0x6F) &&
! 238: (in[2] == 0xA7) && (in[3] == 0x94))
! 239: return(XML_CHAR_ENCODING_EBCDIC);
! 240: if ((in[0] == 0x3C) && (in[1] == 0x3F) &&
! 241: (in[2] == 0x78) && (in[3] == 0x6D))
! 242: return(XML_CHAR_ENCODING_UTF8);
! 243: return(XML_CHAR_ENCODING_NONE);
! 244: }
! 245:
! 246: /**
! 247: * xmlParseCharEncoding:
! 248: * @name: the encoding name as parsed, in UTF-8 format (ASCCI actually)
! 249: *
! 250: * Conpare the string to the known encoding schemes already known. Note
! 251: * that the comparison is case insensitive accordingly to the section
! 252: * [XML] 4.3.3 Character Encoding in Entities.
! 253: *
! 254: * Returns one of the XML_CHAR_ENCODING_... values or XML_CHAR_ENCODING_NONE
! 255: * if not recognized.
! 256: */
! 257: xmlCharEncoding
! 258: xmlParseCharEncoding(char* name)
! 259: {
! 260: char upper[500];
! 261: int i;
! 262:
! 263: for (i = 0;i < 499;i++) {
! 264: upper[i] = toupper(name[i]);
! 265: if (upper[i] == 0) break;
! 266: }
! 267: upper[i] = 0;
! 268:
! 269: if (!strcmp(upper, "")) return(XML_CHAR_ENCODING_NONE);
! 270: if (!strcmp(upper, "UTF-8")) return(XML_CHAR_ENCODING_UTF8);
! 271: if (!strcmp(upper, "UTF8")) return(XML_CHAR_ENCODING_UTF8);
! 272:
! 273: /*
! 274: * NOTE: if we were able to parse this, the endianness of UTF16 is
! 275: * already found and in use
! 276: */
! 277: if (!strcmp(upper, "UTF-16")) return(XML_CHAR_ENCODING_UTF16LE);
! 278: if (!strcmp(upper, "UTF16")) return(XML_CHAR_ENCODING_UTF16LE);
! 279:
! 280: if (!strcmp(upper, "ISO-10646-UCS-2")) return(XML_CHAR_ENCODING_UCS2);
! 281: if (!strcmp(upper, "UCS-2")) return(XML_CHAR_ENCODING_UCS2);
! 282: if (!strcmp(upper, "UCS2")) return(XML_CHAR_ENCODING_UCS2);
! 283:
! 284: /*
! 285: * NOTE: if we were able to parse this, the endianness of UCS4 is
! 286: * already found and in use
! 287: */
! 288: if (!strcmp(upper, "ISO-10646-UCS-4")) return(XML_CHAR_ENCODING_UCS4LE);
! 289: if (!strcmp(upper, "UCS-4")) return(XML_CHAR_ENCODING_UCS4LE);
! 290: if (!strcmp(upper, "UCS4")) return(XML_CHAR_ENCODING_UCS4LE);
! 291:
! 292:
! 293: if (!strcmp(upper, "ISO-8859-1")) return(XML_CHAR_ENCODING_8859_1);
! 294: if (!strcmp(upper, "ISO-LATIN-1")) return(XML_CHAR_ENCODING_8859_1);
! 295: if (!strcmp(upper, "ISO LATIN 1")) return(XML_CHAR_ENCODING_8859_1);
! 296:
! 297: if (!strcmp(upper, "ISO-8859-2")) return(XML_CHAR_ENCODING_8859_2);
! 298: if (!strcmp(upper, "ISO-LATIN-2")) return(XML_CHAR_ENCODING_8859_2);
! 299: if (!strcmp(upper, "ISO LATIN 2")) return(XML_CHAR_ENCODING_8859_2);
! 300:
! 301: if (!strcmp(upper, "ISO-8859-3")) return(XML_CHAR_ENCODING_8859_3);
! 302: if (!strcmp(upper, "ISO-8859-4")) return(XML_CHAR_ENCODING_8859_4);
! 303: if (!strcmp(upper, "ISO-8859-5")) return(XML_CHAR_ENCODING_8859_5);
! 304: if (!strcmp(upper, "ISO-8859-6")) return(XML_CHAR_ENCODING_8859_6);
! 305: if (!strcmp(upper, "ISO-8859-7")) return(XML_CHAR_ENCODING_8859_7);
! 306: if (!strcmp(upper, "ISO-8859-8")) return(XML_CHAR_ENCODING_8859_8);
! 307: if (!strcmp(upper, "ISO-8859-9")) return(XML_CHAR_ENCODING_8859_9);
! 308:
! 309: if (!strcmp(upper, "ISO-2022-JP")) return(XML_CHAR_ENCODING_2022_JP);
! 310: if (!strcmp(upper, "Shift_JIS")) return(XML_CHAR_ENCODING_SHIFT_JIS);
! 311: if (!strcmp(upper, "EUC-JP")) return(XML_CHAR_ENCODING_EUC_JP);
! 312: return(XML_CHAR_ENCODING_ERROR);
! 313: }
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