xref: /PHP-7.4/ext/fileinfo/libmagic/encoding.c (revision fa96c7e0)
1 /*
2  * Copyright (c) Ian F. Darwin 1986-1995.
3  * Software written by Ian F. Darwin and others;
4  * maintained 1995-present by Christos Zoulas and others.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice immediately at the beginning of the file, without modification,
11  *    this list of conditions, and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 /*
29  * Encoding -- determine the character encoding of a text file.
30  *
31  * Joerg Wunsch <joerg@freebsd.org> wrote the original support for 8-bit
32  * international characters.
33  */
34 
35 #include "file.h"
36 
37 #ifndef	lint
38 FILE_RCSID("@(#)$File: encoding.c,v 1.20 2019/04/15 16:48:41 christos Exp $")
39 #endif	/* lint */
40 
41 #include "magic.h"
42 #include <string.h>
43 #include <memory.h>
44 #include <stdlib.h>
45 
46 
47 private int looks_ascii(const unsigned char *, size_t, unichar *, size_t *);
48 private int looks_utf8_with_BOM(const unsigned char *, size_t, unichar *,
49     size_t *);
50 private int looks_utf7(const unsigned char *, size_t, unichar *, size_t *);
51 private int looks_ucs16(const unsigned char *, size_t, unichar *, size_t *);
52 private int looks_ucs32(const unsigned char *, size_t, unichar *, size_t *);
53 private int looks_latin1(const unsigned char *, size_t, unichar *, size_t *);
54 private int looks_extended(const unsigned char *, size_t, unichar *, size_t *);
55 private void from_ebcdic(const unsigned char *, size_t, unsigned char *);
56 
57 #ifdef DEBUG_ENCODING
58 #define DPRINTF(a) printf a
59 #else
60 #define DPRINTF(a)
61 #endif
62 
63 /*
64  * Try to determine whether text is in some character code we can
65  * identify.  Each of these tests, if it succeeds, will leave
66  * the text converted into one-unichar-per-character Unicode in
67  * ubuf, and the number of characters converted in ulen.
68  */
69 protected int
file_encoding(struct magic_set * ms,const struct buffer * b,unichar ** ubuf,size_t * ulen,const char ** code,const char ** code_mime,const char ** type)70 file_encoding(struct magic_set *ms, const struct buffer *b, unichar **ubuf,
71     size_t *ulen, const char **code, const char **code_mime, const char **type)
72 {
73 	const unsigned char *buf = CAST(const unsigned char *, b->fbuf);
74 	size_t nbytes = b->flen > 64*1024 ? 64*1024 : b->flen;
75 	size_t mlen;
76 	int rv = 1, ucs_type;
77 	unsigned char *nbuf = NULL;
78 	unichar *udefbuf;
79 	size_t udeflen;
80 
81 	if (ubuf == NULL)
82 		ubuf = &udefbuf;
83 	if (ulen == NULL)
84 		ulen = &udeflen;
85 
86 	*type = "text";
87 	*ulen = 0;
88 	*code = "unknown";
89 	*code_mime = "binary";
90 
91 	mlen = (nbytes + 1) * sizeof((*ubuf)[0]);
92 	if ((*ubuf = CAST(unichar *, ecalloc(CAST(size_t, 1), mlen))) == NULL) {
93 		file_oomem(ms, mlen);
94 		goto done;
95 	}
96 	mlen = (nbytes + 1) * sizeof(nbuf[0]);
97 	if ((nbuf = CAST(unsigned char *,
98 	    ecalloc(CAST(size_t, 1), mlen))) == NULL) {
99 		file_oomem(ms, mlen);
100 		goto done;
101 	}
102 
103 	if (looks_ascii(buf, nbytes, *ubuf, ulen)) {
104 		if (looks_utf7(buf, nbytes, *ubuf, ulen) > 0) {
105 			DPRINTF(("utf-7 %" SIZE_T_FORMAT "u\n", *ulen));
106 			*code = "UTF-7 Unicode";
107 			*code_mime = "utf-7";
108 		} else {
109 			DPRINTF(("ascii %" SIZE_T_FORMAT "u\n", *ulen));
110 			*code = "ASCII";
111 			*code_mime = "us-ascii";
112 		}
113 	} else if (looks_utf8_with_BOM(buf, nbytes, *ubuf, ulen) > 0) {
114 		DPRINTF(("utf8/bom %" SIZE_T_FORMAT "u\n", *ulen));
115 		*code = "UTF-8 Unicode (with BOM)";
116 		*code_mime = "utf-8";
117 	} else if (file_looks_utf8(buf, nbytes, *ubuf, ulen) > 1) {
118 		DPRINTF(("utf8 %" SIZE_T_FORMAT "u\n", *ulen));
119 		*code = "UTF-8 Unicode";
120 		*code_mime = "utf-8";
121 	} else if ((ucs_type = looks_ucs32(buf, nbytes, *ubuf, ulen)) != 0) {
122 		if (ucs_type == 1) {
123 			*code = "Little-endian UTF-32 Unicode";
124 			*code_mime = "utf-32le";
125 		} else {
126 			*code = "Big-endian UTF-32 Unicode";
127 			*code_mime = "utf-32be";
128 		}
129 		DPRINTF(("ucs32 %" SIZE_T_FORMAT "u\n", *ulen));
130 	} else if ((ucs_type = looks_ucs16(buf, nbytes, *ubuf, ulen)) != 0) {
131 		if (ucs_type == 1) {
132 			*code = "Little-endian UTF-16 Unicode";
133 			*code_mime = "utf-16le";
134 		} else {
135 			*code = "Big-endian UTF-16 Unicode";
136 			*code_mime = "utf-16be";
137 		}
138 		DPRINTF(("ucs16 %" SIZE_T_FORMAT "u\n", *ulen));
139 	} else if (looks_latin1(buf, nbytes, *ubuf, ulen)) {
140 		DPRINTF(("latin1 %" SIZE_T_FORMAT "u\n", *ulen));
141 		*code = "ISO-8859";
142 		*code_mime = "iso-8859-1";
143 	} else if (looks_extended(buf, nbytes, *ubuf, ulen)) {
144 		DPRINTF(("extended %" SIZE_T_FORMAT "u\n", *ulen));
145 		*code = "Non-ISO extended-ASCII";
146 		*code_mime = "unknown-8bit";
147 	} else {
148 		from_ebcdic(buf, nbytes, nbuf);
149 
150 		if (looks_ascii(nbuf, nbytes, *ubuf, ulen)) {
151 			DPRINTF(("ebcdic %" SIZE_T_FORMAT "u\n", *ulen));
152 			*code = "EBCDIC";
153 			*code_mime = "ebcdic";
154 		} else if (looks_latin1(nbuf, nbytes, *ubuf, ulen)) {
155 			DPRINTF(("ebcdic/international %" SIZE_T_FORMAT "u\n",
156 			    *ulen));
157 			*code = "International EBCDIC";
158 			*code_mime = "ebcdic";
159 		} else { /* Doesn't look like text at all */
160 			DPRINTF(("binary\n"));
161 			rv = 0;
162 			*type = "binary";
163 		}
164 	}
165 
166  done:
167 	efree(nbuf);
168 	if (ubuf == &udefbuf)
169 		efree(udefbuf);
170 
171 	return rv;
172 }
173 
174 /*
175  * This table reflects a particular philosophy about what constitutes
176  * "text," and there is room for disagreement about it.
177  *
178  * Version 3.31 of the file command considered a file to be ASCII if
179  * each of its characters was approved by either the isascii() or
180  * isalpha() function.  On most systems, this would mean that any
181  * file consisting only of characters in the range 0x00 ... 0x7F
182  * would be called ASCII text, but many systems might reasonably
183  * consider some characters outside this range to be alphabetic,
184  * so the file command would call such characters ASCII.  It might
185  * have been more accurate to call this "considered textual on the
186  * local system" than "ASCII."
187  *
188  * It considered a file to be "International language text" if each
189  * of its characters was either an ASCII printing character (according
190  * to the real ASCII standard, not the above test), a character in
191  * the range 0x80 ... 0xFF, or one of the following control characters:
192  * backspace, tab, line feed, vertical tab, form feed, carriage return,
193  * escape.  No attempt was made to determine the language in which files
194  * of this type were written.
195  *
196  *
197  * The table below considers a file to be ASCII if all of its characters
198  * are either ASCII printing characters (again, according to the X3.4
199  * standard, not isascii()) or any of the following controls: bell,
200  * backspace, tab, line feed, form feed, carriage return, esc, nextline.
201  *
202  * I include bell because some programs (particularly shell scripts)
203  * use it literally, even though it is rare in normal text.  I exclude
204  * vertical tab because it never seems to be used in real text.  I also
205  * include, with hesitation, the X3.64/ECMA-43 control nextline (0x85),
206  * because that's what the dd EBCDIC->ASCII table maps the EBCDIC newline
207  * character to.  It might be more appropriate to include it in the 8859
208  * set instead of the ASCII set, but it's got to be included in *something*
209  * we recognize or EBCDIC files aren't going to be considered textual.
210  * Some old Unix source files use SO/SI (^N/^O) to shift between Greek
211  * and Latin characters, so these should possibly be allowed.  But they
212  * make a real mess on VT100-style displays if they're not paired properly,
213  * so we are probably better off not calling them text.
214  *
215  * A file is considered to be ISO-8859 text if its characters are all
216  * either ASCII, according to the above definition, or printing characters
217  * from the ISO-8859 8-bit extension, characters 0xA0 ... 0xFF.
218  *
219  * Finally, a file is considered to be international text from some other
220  * character code if its characters are all either ISO-8859 (according to
221  * the above definition) or characters in the range 0x80 ... 0x9F, which
222  * ISO-8859 considers to be control characters but the IBM PC and Macintosh
223  * consider to be printing characters.
224  */
225 
226 #define F 0   /* character never appears in text */
227 #define T 1   /* character appears in plain ASCII text */
228 #define I 2   /* character appears in ISO-8859 text */
229 #define X 3   /* character appears in non-ISO extended ASCII (Mac, IBM PC) */
230 
231 private char text_chars[256] = {
232 	/*                  BEL BS HT LF VT FF CR    */
233 	F, F, F, F, F, F, F, T, T, T, T, T, T, T, F, F,  /* 0x0X */
234 	/*                              ESC          */
235 	F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F,  /* 0x1X */
236 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x2X */
237 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x3X */
238 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x4X */
239 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x5X */
240 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x6X */
241 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F,  /* 0x7X */
242 	/*            NEL                            */
243 	X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X,  /* 0x8X */
244 	X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X,  /* 0x9X */
245 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xaX */
246 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xbX */
247 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xcX */
248 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xdX */
249 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xeX */
250 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I   /* 0xfX */
251 };
252 
253 private int
looks_ascii(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)254 looks_ascii(const unsigned char *buf, size_t nbytes, unichar *ubuf,
255     size_t *ulen)
256 {
257 	size_t i;
258 
259 	*ulen = 0;
260 
261 	for (i = 0; i < nbytes; i++) {
262 		int t = text_chars[buf[i]];
263 
264 		if (t != T)
265 			return 0;
266 
267 		ubuf[(*ulen)++] = buf[i];
268 	}
269 
270 	return 1;
271 }
272 
273 private int
looks_latin1(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)274 looks_latin1(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
275 {
276 	size_t i;
277 
278 	*ulen = 0;
279 
280 	for (i = 0; i < nbytes; i++) {
281 		int t = text_chars[buf[i]];
282 
283 		if (t != T && t != I)
284 			return 0;
285 
286 		ubuf[(*ulen)++] = buf[i];
287 	}
288 
289 	return 1;
290 }
291 
292 private int
looks_extended(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)293 looks_extended(const unsigned char *buf, size_t nbytes, unichar *ubuf,
294     size_t *ulen)
295 {
296 	size_t i;
297 
298 	*ulen = 0;
299 
300 	for (i = 0; i < nbytes; i++) {
301 		int t = text_chars[buf[i]];
302 
303 		if (t != T && t != I && t != X)
304 			return 0;
305 
306 		ubuf[(*ulen)++] = buf[i];
307 	}
308 
309 	return 1;
310 }
311 
312 /*
313  * Decide whether some text looks like UTF-8. Returns:
314  *
315  *     -1: invalid UTF-8
316  *      0: uses odd control characters, so doesn't look like text
317  *      1: 7-bit text
318  *      2: definitely UTF-8 text (valid high-bit set bytes)
319  *
320  * If ubuf is non-NULL on entry, text is decoded into ubuf, *ulen;
321  * ubuf must be big enough!
322  */
323 protected int
file_looks_utf8(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)324 file_looks_utf8(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
325 {
326 	size_t i;
327 	int n;
328 	unichar c;
329 	int gotone = 0, ctrl = 0;
330 
331 	if (ubuf)
332 		*ulen = 0;
333 
334 	for (i = 0; i < nbytes; i++) {
335 		if ((buf[i] & 0x80) == 0) {	   /* 0xxxxxxx is plain ASCII */
336 			/*
337 			 * Even if the whole file is valid UTF-8 sequences,
338 			 * still reject it if it uses weird control characters.
339 			 */
340 
341 			if (text_chars[buf[i]] != T)
342 				ctrl = 1;
343 
344 			if (ubuf)
345 				ubuf[(*ulen)++] = buf[i];
346 		} else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */
347 			return -1;
348 		} else {			   /* 11xxxxxx begins UTF-8 */
349 			int following;
350 
351 			if ((buf[i] & 0x20) == 0) {		/* 110xxxxx */
352 				c = buf[i] & 0x1f;
353 				following = 1;
354 			} else if ((buf[i] & 0x10) == 0) {	/* 1110xxxx */
355 				c = buf[i] & 0x0f;
356 				following = 2;
357 			} else if ((buf[i] & 0x08) == 0) {	/* 11110xxx */
358 				c = buf[i] & 0x07;
359 				following = 3;
360 			} else if ((buf[i] & 0x04) == 0) {	/* 111110xx */
361 				c = buf[i] & 0x03;
362 				following = 4;
363 			} else if ((buf[i] & 0x02) == 0) {	/* 1111110x */
364 				c = buf[i] & 0x01;
365 				following = 5;
366 			} else
367 				return -1;
368 
369 			for (n = 0; n < following; n++) {
370 				i++;
371 				if (i >= nbytes)
372 					goto done;
373 
374 				if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40))
375 					return -1;
376 
377 				c = (c << 6) + (buf[i] & 0x3f);
378 			}
379 
380 			if (ubuf)
381 				ubuf[(*ulen)++] = c;
382 			gotone = 1;
383 		}
384 	}
385 done:
386 	return ctrl ? 0 : (gotone ? 2 : 1);
387 }
388 
389 /*
390  * Decide whether some text looks like UTF-8 with BOM. If there is no
391  * BOM, return -1; otherwise return the result of looks_utf8 on the
392  * rest of the text.
393  */
394 private int
looks_utf8_with_BOM(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)395 looks_utf8_with_BOM(const unsigned char *buf, size_t nbytes, unichar *ubuf,
396     size_t *ulen)
397 {
398 	if (nbytes > 3 && buf[0] == 0xef && buf[1] == 0xbb && buf[2] == 0xbf)
399 		return file_looks_utf8(buf + 3, nbytes - 3, ubuf, ulen);
400 	else
401 		return -1;
402 }
403 
404 private int
looks_utf7(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)405 looks_utf7(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
406 {
407 	if (nbytes > 4 && buf[0] == '+' && buf[1] == '/' && buf[2] == 'v')
408 		switch (buf[3]) {
409 		case '8':
410 		case '9':
411 		case '+':
412 		case '/':
413 			if (ubuf)
414 				*ulen = 0;
415 			return 1;
416 		default:
417 			return -1;
418 		}
419 	else
420 		return -1;
421 }
422 
423 private int
looks_ucs16(const unsigned char * bf,size_t nbytes,unichar * ubf,size_t * ulen)424 looks_ucs16(const unsigned char *bf, size_t nbytes, unichar *ubf,
425     size_t *ulen)
426 {
427 	int bigend;
428 	size_t i;
429 
430 	if (nbytes < 2)
431 		return 0;
432 
433 	if (bf[0] == 0xff && bf[1] == 0xfe)
434 		bigend = 0;
435 	else if (bf[0] == 0xfe && bf[1] == 0xff)
436 		bigend = 1;
437 	else
438 		return 0;
439 
440 	*ulen = 0;
441 
442 	for (i = 2; i + 1 < nbytes; i += 2) {
443 		/* XXX fix to properly handle chars > 65536 */
444 
445 		if (bigend)
446 			ubf[(*ulen)++] = bf[i + 1]
447 			    | (CAST(unichar, bf[i]) << 8);
448 		else
449 			ubf[(*ulen)++] = bf[i]
450 			    | (CAST(unichar, bf[i + 1]) << 8);
451 
452 		if (ubf[*ulen - 1] == 0xfffe)
453 			return 0;
454 		if (ubf[*ulen - 1] < 128 &&
455 		    text_chars[CAST(size_t, ubf[*ulen - 1])] != T)
456 			return 0;
457 	}
458 
459 	return 1 + bigend;
460 }
461 
462 private int
looks_ucs32(const unsigned char * bf,size_t nbytes,unichar * ubf,size_t * ulen)463 looks_ucs32(const unsigned char *bf, size_t nbytes, unichar *ubf,
464     size_t *ulen)
465 {
466 	int bigend;
467 	size_t i;
468 
469 	if (nbytes < 4)
470 		return 0;
471 
472 	if (bf[0] == 0xff && bf[1] == 0xfe && bf[2] == 0 && bf[3] == 0)
473 		bigend = 0;
474 	else if (bf[0] == 0 && bf[1] == 0 && bf[2] == 0xfe && bf[3] == 0xff)
475 		bigend = 1;
476 	else
477 		return 0;
478 
479 	*ulen = 0;
480 
481 	for (i = 4; i + 3 < nbytes; i += 4) {
482 		/* XXX fix to properly handle chars > 65536 */
483 
484 		if (bigend)
485 			ubf[(*ulen)++] = CAST(unichar, bf[i + 3])
486 			    | (CAST(unichar, bf[i + 2]) << 8)
487 			    | (CAST(unichar, bf[i + 1]) << 16)
488 			    | (CAST(unichar, bf[i]) << 24);
489 		else
490 			ubf[(*ulen)++] = CAST(unichar, bf[i + 0])
491 			    | (CAST(unichar, bf[i + 1]) << 8)
492 			    | (CAST(unichar, bf[i + 2]) << 16)
493 			    | (CAST(unichar, bf[i + 3]) << 24);
494 
495 		if (ubf[*ulen - 1] == 0xfffe)
496 			return 0;
497 		if (ubf[*ulen - 1] < 128 &&
498 		    text_chars[CAST(size_t, ubf[*ulen - 1])] != T)
499 			return 0;
500 	}
501 
502 	return 1 + bigend;
503 }
504 #undef F
505 #undef T
506 #undef I
507 #undef X
508 
509 /*
510  * This table maps each EBCDIC character to an (8-bit extended) ASCII
511  * character, as specified in the rationale for the dd(1) command in
512  * draft 11.2 (September, 1991) of the POSIX P1003.2 standard.
513  *
514  * Unfortunately it does not seem to correspond exactly to any of the
515  * five variants of EBCDIC documented in IBM's _Enterprise Systems
516  * Architecture/390: Principles of Operation_, SA22-7201-06, Seventh
517  * Edition, July, 1999, pp. I-1 - I-4.
518  *
519  * Fortunately, though, all versions of EBCDIC, including this one, agree
520  * on most of the printing characters that also appear in (7-bit) ASCII.
521  * Of these, only '|', '!', '~', '^', '[', and ']' are in question at all.
522  *
523  * Fortunately too, there is general agreement that codes 0x00 through
524  * 0x3F represent control characters, 0x41 a nonbreaking space, and the
525  * remainder printing characters.
526  *
527  * This is sufficient to allow us to identify EBCDIC text and to distinguish
528  * between old-style and internationalized examples of text.
529  */
530 
531 private unsigned char ebcdic_to_ascii[] = {
532   0,   1,   2,   3, 156,   9, 134, 127, 151, 141, 142,  11,  12,  13,  14,  15,
533  16,  17,  18,  19, 157, 133,   8, 135,  24,  25, 146, 143,  28,  29,  30,  31,
534 128, 129, 130, 131, 132,  10,  23,  27, 136, 137, 138, 139, 140,   5,   6,   7,
535 144, 145,  22, 147, 148, 149, 150,   4, 152, 153, 154, 155,  20,  21, 158,  26,
536 ' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|',
537 '&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~',
538 '-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?',
539 186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"',
540 195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201,
541 202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208,
542 209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215,
543 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231,
544 '{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237,
545 '}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243,
546 '\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249,
547 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255
548 };
549 
550 #ifdef notdef
551 /*
552  * The following EBCDIC-to-ASCII table may relate more closely to reality,
553  * or at least to modern reality.  It comes from
554  *
555  *   http://ftp.s390.ibm.com/products/oe/bpxqp9.html
556  *
557  * and maps the characters of EBCDIC code page 1047 (the code used for
558  * Unix-derived software on IBM's 390 systems) to the corresponding
559  * characters from ISO 8859-1.
560  *
561  * If this table is used instead of the above one, some of the special
562  * cases for the NEL character can be taken out of the code.
563  */
564 
565 private unsigned char ebcdic_1047_to_8859[] = {
566 0x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F,
567 0x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F,
568 0x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07,
569 0x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A,
570 0x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C,
571 0x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E,
572 0x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F,
573 0xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22,
574 0xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1,
575 0xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4,
576 0xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE,
577 0xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7,
578 0x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5,
579 0x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF,
580 0x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5,
581 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F
582 };
583 #endif
584 
585 /*
586  * Copy buf[0 ... nbytes-1] into out[], translating EBCDIC to ASCII.
587  */
588 private void
from_ebcdic(const unsigned char * buf,size_t nbytes,unsigned char * out)589 from_ebcdic(const unsigned char *buf, size_t nbytes, unsigned char *out)
590 {
591 	size_t i;
592 
593 	for (i = 0; i < nbytes; i++) {
594 		out[i] = ebcdic_to_ascii[buf[i]];
595 	}
596 }
597