113 rv = 0;
114 *type = "binary";
115 }
116 }
117
118 done:
119 if (nbuf)
120 free(nbuf);
121
122 return rv;
123}
124
125/*
126 * This table reflects a particular philosophy about what constitutes
127 * "text," and there is room for disagreement about it.
128 *
129 * Version 3.31 of the file command considered a file to be ASCII if
130 * each of its characters was approved by either the isascii() or
131 * isalpha() function. On most systems, this would mean that any
132 * file consisting only of characters in the range 0x00 ... 0x7F
133 * would be called ASCII text, but many systems might reasonably
134 * consider some characters outside this range to be alphabetic,
135 * so the file command would call such characters ASCII. It might
136 * have been more accurate to call this "considered textual on the
137 * local system" than "ASCII."
138 *
139 * It considered a file to be "International language text" if each
140 * of its characters was either an ASCII printing character (according
141 * to the real ASCII standard, not the above test), a character in
142 * the range 0x80 ... 0xFF, or one of the following control characters:
143 * backspace, tab, line feed, vertical tab, form feed, carriage return,
144 * escape. No attempt was made to determine the language in which files
145 * of this type were written.
146 *
147 *
148 * The table below considers a file to be ASCII if all of its characters
149 * are either ASCII printing characters (again, according to the X3.4
150 * standard, not isascii()) or any of the following controls: bell,
151 * backspace, tab, line feed, form feed, carriage return, esc, nextline.
152 *
153 * I include bell because some programs (particularly shell scripts)
154 * use it literally, even though it is rare in normal text. I exclude
155 * vertical tab because it never seems to be used in real text. I also
156 * include, with hesitation, the X3.64/ECMA-43 control nextline (0x85),
157 * because that's what the dd EBCDIC->ASCII table maps the EBCDIC newline
158 * character to. It might be more appropriate to include it in the 8859
159 * set instead of the ASCII set, but it's got to be included in *something*
160 * we recognize or EBCDIC files aren't going to be considered textual.
161 * Some old Unix source files use SO/SI (^N/^O) to shift between Greek
162 * and Latin characters, so these should possibly be allowed. But they
163 * make a real mess on VT100-style displays if they're not paired properly,
164 * so we are probably better off not calling them text.
165 *
166 * A file is considered to be ISO-8859 text if its characters are all
167 * either ASCII, according to the above definition, or printing characters
168 * from the ISO-8859 8-bit extension, characters 0xA0 ... 0xFF.
169 *
170 * Finally, a file is considered to be international text from some other
171 * character code if its characters are all either ISO-8859 (according to
172 * the above definition) or characters in the range 0x80 ... 0x9F, which
173 * ISO-8859 considers to be control characters but the IBM PC and Macintosh
174 * consider to be printing characters.
175 */
176
177#define F 0 /* character never appears in text */
178#define T 1 /* character appears in plain ASCII text */
179#define I 2 /* character appears in ISO-8859 text */
180#define X 3 /* character appears in non-ISO extended ASCII (Mac, IBM PC) */
181
182private char text_chars[256] = {
183 /* BEL BS HT LF FF CR */
184 F, F, F, F, F, F, F, T, T, T, T, F, T, T, F, F, /* 0x0X */
185 /* ESC */
186 F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F, /* 0x1X */
187 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x2X */
188 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x3X */
189 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x4X */
190 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x5X */
191 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x6X */
192 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, /* 0x7X */
193 /* NEL */
194 X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X, /* 0x8X */
195 X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, /* 0x9X */
196 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xaX */
197 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xbX */
198 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xcX */
199 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xdX */
200 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xeX */
201 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I /* 0xfX */
202};
203
204private int
205looks_ascii(const unsigned char *buf, size_t nbytes, unichar *ubuf,
206 size_t *ulen)
207{
208 size_t i;
209
210 *ulen = 0;
211
212 for (i = 0; i < nbytes; i++) {
213 int t = text_chars[buf[i]];
214
215 if (t != T)
216 return 0;
217
218 ubuf[(*ulen)++] = buf[i];
219 }
220
221 return 1;
222}
223
224private int
225looks_latin1(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
226{
227 size_t i;
228
229 *ulen = 0;
230
231 for (i = 0; i < nbytes; i++) {
232 int t = text_chars[buf[i]];
233
234 if (t != T && t != I)
235 return 0;
236
237 ubuf[(*ulen)++] = buf[i];
238 }
239
240 return 1;
241}
242
243private int
244looks_extended(const unsigned char *buf, size_t nbytes, unichar *ubuf,
245 size_t *ulen)
246{
247 size_t i;
248
249 *ulen = 0;
250
251 for (i = 0; i < nbytes; i++) {
252 int t = text_chars[buf[i]];
253
254 if (t != T && t != I && t != X)
255 return 0;
256
257 ubuf[(*ulen)++] = buf[i];
258 }
259
260 return 1;
261}
262
263/*
264 * Decide whether some text looks like UTF-8. Returns:
265 *
266 * -1: invalid UTF-8
267 * 0: uses odd control characters, so doesn't look like text
268 * 1: 7-bit text
269 * 2: definitely UTF-8 text (valid high-bit set bytes)
270 *
271 * If ubuf is non-NULL on entry, text is decoded into ubuf, *ulen;
272 * ubuf must be big enough!
273 */
274protected int
275file_looks_utf8(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
276{
277 size_t i;
278 int n;
279 unichar c;
280 int gotone = 0, ctrl = 0;
281
282 if (ubuf)
283 *ulen = 0;
284
285 for (i = 0; i < nbytes; i++) {
286 if ((buf[i] & 0x80) == 0) { /* 0xxxxxxx is plain ASCII */
287 /*
288 * Even if the whole file is valid UTF-8 sequences,
289 * still reject it if it uses weird control characters.
290 */
291
292 if (text_chars[buf[i]] != T)
293 ctrl = 1;
294
295 if (ubuf)
296 ubuf[(*ulen)++] = buf[i];
297 } else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */
298 return -1;
299 } else { /* 11xxxxxx begins UTF-8 */
300 int following;
301
302 if ((buf[i] & 0x20) == 0) { /* 110xxxxx */
303 c = buf[i] & 0x1f;
304 following = 1;
305 } else if ((buf[i] & 0x10) == 0) { /* 1110xxxx */
306 c = buf[i] & 0x0f;
307 following = 2;
308 } else if ((buf[i] & 0x08) == 0) { /* 11110xxx */
309 c = buf[i] & 0x07;
310 following = 3;
311 } else if ((buf[i] & 0x04) == 0) { /* 111110xx */
312 c = buf[i] & 0x03;
313 following = 4;
314 } else if ((buf[i] & 0x02) == 0) { /* 1111110x */
315 c = buf[i] & 0x01;
316 following = 5;
317 } else
318 return -1;
319
320 for (n = 0; n < following; n++) {
321 i++;
322 if (i >= nbytes)
323 goto done;
324
325 if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40))
326 return -1;
327
328 c = (c << 6) + (buf[i] & 0x3f);
329 }
330
331 if (ubuf)
332 ubuf[(*ulen)++] = c;
333 gotone = 1;
334 }
335 }
336done:
337 return ctrl ? 0 : (gotone ? 2 : 1);
338}
339
340/*
341 * Decide whether some text looks like UTF-8 with BOM. If there is no
342 * BOM, return -1; otherwise return the result of looks_utf8 on the
343 * rest of the text.
344 */
345private int
346looks_utf8_with_BOM(const unsigned char *buf, size_t nbytes, unichar *ubuf,
347 size_t *ulen)
348{
349 if (nbytes > 3 && buf[0] == 0xef && buf[1] == 0xbb && buf[2] == 0xbf)
350 return file_looks_utf8(buf + 3, nbytes - 3, ubuf, ulen);
351 else
352 return -1;
353}
354
355private int
356looks_ucs16(const unsigned char *buf, size_t nbytes, unichar *ubuf,
357 size_t *ulen)
358{
359 int bigend;
360 size_t i;
361
362 if (nbytes < 2)
363 return 0;
364
365 if (buf[0] == 0xff && buf[1] == 0xfe)
366 bigend = 0;
367 else if (buf[0] == 0xfe && buf[1] == 0xff)
368 bigend = 1;
369 else
370 return 0;
371
372 *ulen = 0;
373
374 for (i = 2; i + 1 < nbytes; i += 2) {
375 /* XXX fix to properly handle chars > 65536 */
376
377 if (bigend)
378 ubuf[(*ulen)++] = buf[i + 1] + 256 * buf[i];
379 else
380 ubuf[(*ulen)++] = buf[i] + 256 * buf[i + 1];
381
382 if (ubuf[*ulen - 1] == 0xfffe)
383 return 0;
384 if (ubuf[*ulen - 1] < 128 &&
385 text_chars[(size_t)ubuf[*ulen - 1]] != T)
386 return 0;
387 }
388
389 return 1 + bigend;
390}
391
392#undef F
393#undef T
394#undef I
395#undef X
396
397/*
398 * This table maps each EBCDIC character to an (8-bit extended) ASCII
399 * character, as specified in the rationale for the dd(1) command in
400 * draft 11.2 (September, 1991) of the POSIX P1003.2 standard.
401 *
402 * Unfortunately it does not seem to correspond exactly to any of the
403 * five variants of EBCDIC documented in IBM's _Enterprise Systems
404 * Architecture/390: Principles of Operation_, SA22-7201-06, Seventh
405 * Edition, July, 1999, pp. I-1 - I-4.
406 *
407 * Fortunately, though, all versions of EBCDIC, including this one, agree
408 * on most of the printing characters that also appear in (7-bit) ASCII.
409 * Of these, only '|', '!', '~', '^', '[', and ']' are in question at all.
410 *
411 * Fortunately too, there is general agreement that codes 0x00 through
412 * 0x3F represent control characters, 0x41 a nonbreaking space, and the
413 * remainder printing characters.
414 *
415 * This is sufficient to allow us to identify EBCDIC text and to distinguish
416 * between old-style and internationalized examples of text.
417 */
418
419private unsigned char ebcdic_to_ascii[] = {
420 0, 1, 2, 3, 156, 9, 134, 127, 151, 141, 142, 11, 12, 13, 14, 15,
421 16, 17, 18, 19, 157, 133, 8, 135, 24, 25, 146, 143, 28, 29, 30, 31,
422128, 129, 130, 131, 132, 10, 23, 27, 136, 137, 138, 139, 140, 5, 6, 7,
423144, 145, 22, 147, 148, 149, 150, 4, 152, 153, 154, 155, 20, 21, 158, 26,
424' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|',
425'&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~',
426'-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?',
427186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"',
428195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201,
429202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208,
430209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215,
431216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231,
432'{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237,
433'}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243,
434'\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249,
435'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255
436};
437
438#ifdef notdef
439/*
440 * The following EBCDIC-to-ASCII table may relate more closely to reality,
441 * or at least to modern reality. It comes from
442 *
443 * http://ftp.s390.ibm.com/products/oe/bpxqp9.html
444 *
445 * and maps the characters of EBCDIC code page 1047 (the code used for
446 * Unix-derived software on IBM's 390 systems) to the corresponding
447 * characters from ISO 8859-1.
448 *
449 * If this table is used instead of the above one, some of the special
450 * cases for the NEL character can be taken out of the code.
451 */
452
453private unsigned char ebcdic_1047_to_8859[] = {
4540x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F,
4550x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F,
4560x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07,
4570x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A,
4580x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C,
4590x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E,
4600x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F,
4610xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22,
4620xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1,
4630xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4,
4640xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE,
4650xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7,
4660x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5,
4670x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF,
4680x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5,
4690x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F
470};
471#endif
472
473/*
474 * Copy buf[0 ... nbytes-1] into out[], translating EBCDIC to ASCII.
475 */
476private void
477from_ebcdic(const unsigned char *buf, size_t nbytes, unsigned char *out)
478{
479 size_t i;
480
481 for (i = 0; i < nbytes; i++) {
482 out[i] = ebcdic_to_ascii[buf[i]];
483 }
484}
| 130 rv = 0;
131 *type = "binary";
132 }
133 }
134
135 done:
136 if (nbuf)
137 free(nbuf);
138
139 return rv;
140}
141
142/*
143 * This table reflects a particular philosophy about what constitutes
144 * "text," and there is room for disagreement about it.
145 *
146 * Version 3.31 of the file command considered a file to be ASCII if
147 * each of its characters was approved by either the isascii() or
148 * isalpha() function. On most systems, this would mean that any
149 * file consisting only of characters in the range 0x00 ... 0x7F
150 * would be called ASCII text, but many systems might reasonably
151 * consider some characters outside this range to be alphabetic,
152 * so the file command would call such characters ASCII. It might
153 * have been more accurate to call this "considered textual on the
154 * local system" than "ASCII."
155 *
156 * It considered a file to be "International language text" if each
157 * of its characters was either an ASCII printing character (according
158 * to the real ASCII standard, not the above test), a character in
159 * the range 0x80 ... 0xFF, or one of the following control characters:
160 * backspace, tab, line feed, vertical tab, form feed, carriage return,
161 * escape. No attempt was made to determine the language in which files
162 * of this type were written.
163 *
164 *
165 * The table below considers a file to be ASCII if all of its characters
166 * are either ASCII printing characters (again, according to the X3.4
167 * standard, not isascii()) or any of the following controls: bell,
168 * backspace, tab, line feed, form feed, carriage return, esc, nextline.
169 *
170 * I include bell because some programs (particularly shell scripts)
171 * use it literally, even though it is rare in normal text. I exclude
172 * vertical tab because it never seems to be used in real text. I also
173 * include, with hesitation, the X3.64/ECMA-43 control nextline (0x85),
174 * because that's what the dd EBCDIC->ASCII table maps the EBCDIC newline
175 * character to. It might be more appropriate to include it in the 8859
176 * set instead of the ASCII set, but it's got to be included in *something*
177 * we recognize or EBCDIC files aren't going to be considered textual.
178 * Some old Unix source files use SO/SI (^N/^O) to shift between Greek
179 * and Latin characters, so these should possibly be allowed. But they
180 * make a real mess on VT100-style displays if they're not paired properly,
181 * so we are probably better off not calling them text.
182 *
183 * A file is considered to be ISO-8859 text if its characters are all
184 * either ASCII, according to the above definition, or printing characters
185 * from the ISO-8859 8-bit extension, characters 0xA0 ... 0xFF.
186 *
187 * Finally, a file is considered to be international text from some other
188 * character code if its characters are all either ISO-8859 (according to
189 * the above definition) or characters in the range 0x80 ... 0x9F, which
190 * ISO-8859 considers to be control characters but the IBM PC and Macintosh
191 * consider to be printing characters.
192 */
193
194#define F 0 /* character never appears in text */
195#define T 1 /* character appears in plain ASCII text */
196#define I 2 /* character appears in ISO-8859 text */
197#define X 3 /* character appears in non-ISO extended ASCII (Mac, IBM PC) */
198
199private char text_chars[256] = {
200 /* BEL BS HT LF FF CR */
201 F, F, F, F, F, F, F, T, T, T, T, F, T, T, F, F, /* 0x0X */
202 /* ESC */
203 F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F, /* 0x1X */
204 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x2X */
205 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x3X */
206 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x4X */
207 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x5X */
208 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x6X */
209 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, /* 0x7X */
210 /* NEL */
211 X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X, /* 0x8X */
212 X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, /* 0x9X */
213 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xaX */
214 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xbX */
215 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xcX */
216 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xdX */
217 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xeX */
218 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I /* 0xfX */
219};
220
221private int
222looks_ascii(const unsigned char *buf, size_t nbytes, unichar *ubuf,
223 size_t *ulen)
224{
225 size_t i;
226
227 *ulen = 0;
228
229 for (i = 0; i < nbytes; i++) {
230 int t = text_chars[buf[i]];
231
232 if (t != T)
233 return 0;
234
235 ubuf[(*ulen)++] = buf[i];
236 }
237
238 return 1;
239}
240
241private int
242looks_latin1(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
243{
244 size_t i;
245
246 *ulen = 0;
247
248 for (i = 0; i < nbytes; i++) {
249 int t = text_chars[buf[i]];
250
251 if (t != T && t != I)
252 return 0;
253
254 ubuf[(*ulen)++] = buf[i];
255 }
256
257 return 1;
258}
259
260private int
261looks_extended(const unsigned char *buf, size_t nbytes, unichar *ubuf,
262 size_t *ulen)
263{
264 size_t i;
265
266 *ulen = 0;
267
268 for (i = 0; i < nbytes; i++) {
269 int t = text_chars[buf[i]];
270
271 if (t != T && t != I && t != X)
272 return 0;
273
274 ubuf[(*ulen)++] = buf[i];
275 }
276
277 return 1;
278}
279
280/*
281 * Decide whether some text looks like UTF-8. Returns:
282 *
283 * -1: invalid UTF-8
284 * 0: uses odd control characters, so doesn't look like text
285 * 1: 7-bit text
286 * 2: definitely UTF-8 text (valid high-bit set bytes)
287 *
288 * If ubuf is non-NULL on entry, text is decoded into ubuf, *ulen;
289 * ubuf must be big enough!
290 */
291protected int
292file_looks_utf8(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
293{
294 size_t i;
295 int n;
296 unichar c;
297 int gotone = 0, ctrl = 0;
298
299 if (ubuf)
300 *ulen = 0;
301
302 for (i = 0; i < nbytes; i++) {
303 if ((buf[i] & 0x80) == 0) { /* 0xxxxxxx is plain ASCII */
304 /*
305 * Even if the whole file is valid UTF-8 sequences,
306 * still reject it if it uses weird control characters.
307 */
308
309 if (text_chars[buf[i]] != T)
310 ctrl = 1;
311
312 if (ubuf)
313 ubuf[(*ulen)++] = buf[i];
314 } else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */
315 return -1;
316 } else { /* 11xxxxxx begins UTF-8 */
317 int following;
318
319 if ((buf[i] & 0x20) == 0) { /* 110xxxxx */
320 c = buf[i] & 0x1f;
321 following = 1;
322 } else if ((buf[i] & 0x10) == 0) { /* 1110xxxx */
323 c = buf[i] & 0x0f;
324 following = 2;
325 } else if ((buf[i] & 0x08) == 0) { /* 11110xxx */
326 c = buf[i] & 0x07;
327 following = 3;
328 } else if ((buf[i] & 0x04) == 0) { /* 111110xx */
329 c = buf[i] & 0x03;
330 following = 4;
331 } else if ((buf[i] & 0x02) == 0) { /* 1111110x */
332 c = buf[i] & 0x01;
333 following = 5;
334 } else
335 return -1;
336
337 for (n = 0; n < following; n++) {
338 i++;
339 if (i >= nbytes)
340 goto done;
341
342 if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40))
343 return -1;
344
345 c = (c << 6) + (buf[i] & 0x3f);
346 }
347
348 if (ubuf)
349 ubuf[(*ulen)++] = c;
350 gotone = 1;
351 }
352 }
353done:
354 return ctrl ? 0 : (gotone ? 2 : 1);
355}
356
357/*
358 * Decide whether some text looks like UTF-8 with BOM. If there is no
359 * BOM, return -1; otherwise return the result of looks_utf8 on the
360 * rest of the text.
361 */
362private int
363looks_utf8_with_BOM(const unsigned char *buf, size_t nbytes, unichar *ubuf,
364 size_t *ulen)
365{
366 if (nbytes > 3 && buf[0] == 0xef && buf[1] == 0xbb && buf[2] == 0xbf)
367 return file_looks_utf8(buf + 3, nbytes - 3, ubuf, ulen);
368 else
369 return -1;
370}
371
372private int
373looks_ucs16(const unsigned char *buf, size_t nbytes, unichar *ubuf,
374 size_t *ulen)
375{
376 int bigend;
377 size_t i;
378
379 if (nbytes < 2)
380 return 0;
381
382 if (buf[0] == 0xff && buf[1] == 0xfe)
383 bigend = 0;
384 else if (buf[0] == 0xfe && buf[1] == 0xff)
385 bigend = 1;
386 else
387 return 0;
388
389 *ulen = 0;
390
391 for (i = 2; i + 1 < nbytes; i += 2) {
392 /* XXX fix to properly handle chars > 65536 */
393
394 if (bigend)
395 ubuf[(*ulen)++] = buf[i + 1] + 256 * buf[i];
396 else
397 ubuf[(*ulen)++] = buf[i] + 256 * buf[i + 1];
398
399 if (ubuf[*ulen - 1] == 0xfffe)
400 return 0;
401 if (ubuf[*ulen - 1] < 128 &&
402 text_chars[(size_t)ubuf[*ulen - 1]] != T)
403 return 0;
404 }
405
406 return 1 + bigend;
407}
408
409#undef F
410#undef T
411#undef I
412#undef X
413
414/*
415 * This table maps each EBCDIC character to an (8-bit extended) ASCII
416 * character, as specified in the rationale for the dd(1) command in
417 * draft 11.2 (September, 1991) of the POSIX P1003.2 standard.
418 *
419 * Unfortunately it does not seem to correspond exactly to any of the
420 * five variants of EBCDIC documented in IBM's _Enterprise Systems
421 * Architecture/390: Principles of Operation_, SA22-7201-06, Seventh
422 * Edition, July, 1999, pp. I-1 - I-4.
423 *
424 * Fortunately, though, all versions of EBCDIC, including this one, agree
425 * on most of the printing characters that also appear in (7-bit) ASCII.
426 * Of these, only '|', '!', '~', '^', '[', and ']' are in question at all.
427 *
428 * Fortunately too, there is general agreement that codes 0x00 through
429 * 0x3F represent control characters, 0x41 a nonbreaking space, and the
430 * remainder printing characters.
431 *
432 * This is sufficient to allow us to identify EBCDIC text and to distinguish
433 * between old-style and internationalized examples of text.
434 */
435
436private unsigned char ebcdic_to_ascii[] = {
437 0, 1, 2, 3, 156, 9, 134, 127, 151, 141, 142, 11, 12, 13, 14, 15,
438 16, 17, 18, 19, 157, 133, 8, 135, 24, 25, 146, 143, 28, 29, 30, 31,
439128, 129, 130, 131, 132, 10, 23, 27, 136, 137, 138, 139, 140, 5, 6, 7,
440144, 145, 22, 147, 148, 149, 150, 4, 152, 153, 154, 155, 20, 21, 158, 26,
441' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|',
442'&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~',
443'-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?',
444186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"',
445195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201,
446202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208,
447209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215,
448216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231,
449'{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237,
450'}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243,
451'\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249,
452'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255
453};
454
455#ifdef notdef
456/*
457 * The following EBCDIC-to-ASCII table may relate more closely to reality,
458 * or at least to modern reality. It comes from
459 *
460 * http://ftp.s390.ibm.com/products/oe/bpxqp9.html
461 *
462 * and maps the characters of EBCDIC code page 1047 (the code used for
463 * Unix-derived software on IBM's 390 systems) to the corresponding
464 * characters from ISO 8859-1.
465 *
466 * If this table is used instead of the above one, some of the special
467 * cases for the NEL character can be taken out of the code.
468 */
469
470private unsigned char ebcdic_1047_to_8859[] = {
4710x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F,
4720x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F,
4730x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07,
4740x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A,
4750x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C,
4760x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E,
4770x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F,
4780xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22,
4790xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1,
4800xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4,
4810xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE,
4820xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7,
4830x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5,
4840x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF,
4850x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5,
4860x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F
487};
488#endif
489
490/*
491 * Copy buf[0 ... nbytes-1] into out[], translating EBCDIC to ASCII.
492 */
493private void
494from_ebcdic(const unsigned char *buf, size_t nbytes, unsigned char *out)
495{
496 size_t i;
497
498 for (i = 0; i < nbytes; i++) {
499 out[i] = ebcdic_to_ascii[buf[i]];
500 }
501}
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