1 /*	$OpenBSD: ascmagic.c,v 1.8 2004/05/19 02:32:35 tedu Exp $ */
2 /*
3  * Copyright (c) Ian F. Darwin 1986-1995.
4  * Software written by Ian F. Darwin and others;
5  * maintained 1995-present by Christos Zoulas and others.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice immediately at the beginning of the file, without modification,
12  *    this list of conditions, and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 /*
30  * ASCII magic -- file types that we know based on keywords
31  * that can appear anywhere in the file.
32  *
33  * Extensively modified by Eric Fischer <enf@pobox.com> in July, 2000,
34  * to handle character codes other than ASCII on a unified basis.
35  *
36  * Joerg Wunsch <joerg@freebsd.org> wrote the original support for 8-bit
37  * international characters, now subsumed into this file.
38  */
39 
40 #include "file.h"
41 #include "magic.h"
42 #include <stdio.h>
43 #include <string.h>
44 #include <memory.h>
45 #include <ctype.h>
46 #include <stdlib.h>
47 #ifdef HAVE_UNISTD_H
48 #include <unistd.h>
49 #endif
50 #include "names.h"
51 
52 __RCSID("$MirOS: src/usr.bin/file/ascmagic.c,v 1.2 2007/07/10 14:22:35 tg Exp $");
53 
54 typedef unsigned long unichar;
55 
56 #define MAXLINELEN 300	/* longest sane line length */
57 #define ISSPC(x) ((x) == ' ' || (x) == '\t' || (x) == '\r' || (x) == '\n' \
58 		  || (x) == 0x85 || (x) == '\f')
59 
60 private int looks_ascii(const unsigned char *, size_t, unichar *, size_t *);
61 private int looks_utf8(const unsigned char *, size_t, unichar *, size_t *);
62 private int looks_unicode(const unsigned char *, size_t, unichar *, size_t *);
63 private int looks_latin1(const unsigned char *, size_t, unichar *, size_t *);
64 private int looks_extended(const unsigned char *, size_t, unichar *, size_t *);
65 private void from_ebcdic(const unsigned char *, size_t, unsigned char *);
66 private int ascmatch(const unsigned char *, const unichar *, size_t);
67 
68 
69 protected int
file_ascmagic(struct magic_set * ms,const unsigned char * buf,size_t nbytes)70 file_ascmagic(struct magic_set *ms, const unsigned char *buf, size_t nbytes)
71 {
72 	ssize_t i;
73 	unsigned char nbuf[HOWMANY+1];	/* one extra for terminating '\0' */
74 	unichar ubuf[HOWMANY+1];	/* one extra for terminating '\0' */
75 	ssize_t ulen;
76 	struct names *p;
77 
78 	const char *code = NULL;
79 	const char *code_mime = NULL;
80 	const char *type = NULL;
81 	const char *subtype = NULL;
82 	const char *subtype_mime = NULL;
83 
84 	int has_escapes = 0;
85 	int has_backspace = 0;
86 
87 	int n_crlf = 0;
88 	int n_lf = 0;
89 	int n_cr = 0;
90 	int n_nel = 0;
91 
92 	int last_line_end = -1;
93 	int has_long_lines = 0;
94 
95 	/*
96 	 * Undo the NUL-termination kindly provided by process()
97 	 * but leave at least one byte to look at
98 	 */
99 
100 	while (nbytes > 1 && buf[nbytes - 1] == '\0')
101 		nbytes--;
102 
103 	/* nbuf and ubuf relies on this */
104 	if (nbytes > HOWMANY)
105 		nbytes = HOWMANY;
106 
107 	/*
108 	 * Then try to determine whether it's any character code we can
109 	 * identify.  Each of these tests, if it succeeds, will leave
110 	 * the text converted into one-unichar-per-character Unicode in
111 	 * ubuf, and the number of characters converted in ulen.
112 	 */
113 	if (looks_ascii(buf, nbytes, ubuf, &ulen)) {
114 		code = "ASCII";
115 		code_mime = "us-ascii";
116 		type = "text";
117 	} else if (looks_utf8(buf, nbytes, ubuf, &ulen)) {
118 		code = "UTF-8 Unicode";
119 		code_mime = "utf-8";
120 		type = "text";
121 	} else if ((i = looks_unicode(buf, nbytes, ubuf, &ulen)) != 0) {
122 		if (i == 1)
123 			code = "Little-endian UTF-16 Unicode";
124 		else
125 			code = "Big-endian UTF-16 Unicode";
126 
127 		type = "character data";
128 		code_mime = "utf-16";    /* is this defined? */
129 	} else if (looks_latin1(buf, nbytes, ubuf, &ulen)) {
130 		code = "ISO-8859";
131 		type = "text";
132 		code_mime = "iso-8859-1";
133 	} else if (looks_extended(buf, nbytes, ubuf, &ulen)) {
134 		code = "Non-ISO extended-ASCII";
135 		type = "text";
136 		code_mime = "unknown";
137 	} else {
138 		from_ebcdic(buf, nbytes, nbuf);
139 
140 		if (looks_ascii(nbuf, nbytes, ubuf, &ulen)) {
141 			code = "EBCDIC";
142 			type = "character data";
143 			code_mime = "ebcdic";
144 		} else if (looks_latin1(nbuf, nbytes, ubuf, &ulen)) {
145 			code = "International EBCDIC";
146 			type = "character data";
147 			code_mime = "ebcdic";
148 		} else {
149 			return 0;  /* doesn't look like text at all */
150 		}
151 	}
152 
153 	/*
154 	 * for troff, look for . + letter + letter or .\";
155 	 * this must be done to disambiguate tar archives' ./file
156 	 * and other trash from real troff input.
157 	 *
158 	 * I believe Plan 9 troff allows non-ASCII characters in the names
159 	 * of macros, so this test might possibly fail on such a file.
160 	 */
161 	if (*ubuf == '.') {
162 		unichar *tp = ubuf + 1;
163 
164 		while (ISSPC(*tp))
165 			++tp;	/* skip leading whitespace */
166 		if ((tp[0] == '\\' && tp[1] == '\"') ||
167 		    (isascii((unsigned char)tp[0]) &&
168 		     isalnum((unsigned char)tp[0]) &&
169 		     isascii((unsigned char)tp[1]) &&
170 		     isalnum((unsigned char)tp[1]) &&
171 		     ISSPC(tp[2]))) {
172 			subtype_mime = "text/troff";
173 			subtype = "troff or preprocessor input";
174 			goto subtype_identified;
175 		}
176 	}
177 
178 	if ((*buf == 'c' || *buf == 'C') && ISSPC(buf[1])) {
179 		subtype_mime = "text/fortran";
180 		subtype = "fortran program";
181 		goto subtype_identified;
182 	}
183 
184 	/* look for tokens from names.h - this is expensive! */
185 
186 	i = 0;
187 	while (i < ulen) {
188 		size_t end;
189 
190 		/*
191 		 * skip past any leading space
192 		 */
193 		while (i < ulen && ISSPC(ubuf[i]))
194 			i++;
195 		if (i >= ulen)
196 			break;
197 
198 		/*
199 		 * find the next whitespace
200 		 */
201 		for (end = i + 1; end < nbytes; end++)
202 			if (ISSPC(ubuf[end]))
203 				break;
204 
205 		/*
206 		 * compare the word thus isolated against the token list
207 		 */
208 		for (p = names; p < names + NNAMES; p++) {
209 			if (ascmatch((const unsigned char *)p->name, ubuf + i,
210 			    end - i)) {
211 				subtype = types[p->type].human;
212 				subtype_mime = types[p->type].mime;
213 				goto subtype_identified;
214 			}
215 		}
216 
217 		i = end;
218 	}
219 
220 subtype_identified:
221 
222 	/*
223 	 * Now try to discover other details about the file.
224 	 */
225 	for (i = 0; i < ulen; i++) {
226 		if (i > last_line_end + MAXLINELEN)
227 			has_long_lines = 1;
228 
229 		if (ubuf[i] == '\033')
230 			has_escapes = 1;
231 		if (ubuf[i] == '\b')
232 			has_backspace = 1;
233 
234 		if (ubuf[i] == '\r' && (i + 1 <  ulen && ubuf[i + 1] == '\n')) {
235 			n_crlf++;
236 			last_line_end = i;
237 		}
238 		if (ubuf[i] == '\r' && (i + 1 >= ulen || ubuf[i + 1] != '\n')) {
239 			n_cr++;
240 			last_line_end = i;
241 		}
242 		if (ubuf[i] == '\n' && ((int)i - 1 < 0 || ubuf[i - 1] != '\r')){
243 			n_lf++;
244 			last_line_end = i;
245 		}
246 		if (ubuf[i] == 0x85) { /* X3.64/ECMA-43 "next line" character */
247 			n_nel++;
248 			last_line_end = i;
249 		}
250 	}
251 
252 	if ((ms->flags & MAGIC_MIME)) {
253 		if (subtype_mime) {
254 			if (file_printf(ms, subtype_mime) == -1)
255 				return -1;
256 		} else {
257 			if (file_printf(ms, "text/plain") == -1)
258 				return -1;
259 		}
260 
261 		if (code_mime) {
262 			if (file_printf(ms, "; charset=") == -1)
263 				return -1;
264 			if (file_printf(ms, code_mime) == -1)
265 				return -1;
266 		}
267 	} else {
268 		if (file_printf(ms, code) == -1)
269 			return -1;
270 
271 		if (subtype) {
272 			if (file_printf(ms, " ") == -1)
273 				return -1;
274 			if (file_printf(ms, subtype) == -1)
275 				return -1;
276 		}
277 
278 		if (file_printf(ms, " ") == -1)
279 			return -1;
280 		if (file_printf(ms, type) == -1)
281 			return -1;
282 
283 		if (has_long_lines)
284 			if (file_printf(ms, ", with very long lines") == -1)
285 				return -1;
286 
287 		/*
288 		 * Only report line terminators if we find one other than LF,
289 		 * or if we find none at all.
290 		 */
291 		if ((n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0) ||
292 		    (n_crlf != 0 || n_cr != 0 || n_nel != 0)) {
293 			if (file_printf(ms, ", with") == -1)
294 				return -1;
295 
296 			if (n_crlf == 0 && n_cr == 0 && n_nel == 0 && n_lf == 0)			{
297 				if (file_printf(ms, " no") == -1)
298 					return -1;
299 			} else {
300 				if (n_crlf) {
301 					if (file_printf(ms, " CRLF") == -1)
302 						return -1;
303 					if (n_cr || n_lf || n_nel)
304 						if (file_printf(ms, ",") == -1)
305 							return -1;
306 				}
307 				if (n_cr) {
308 					if (file_printf(ms, " CR") == -1)
309 						return -1;
310 					if (n_lf || n_nel)
311 						if (file_printf(ms, ",") == -1)
312 							return -1;
313 				}
314 				if (n_lf) {
315 					if (file_printf(ms, " LF") == -1)
316 						return -1;
317 					if (n_nel)
318 						if (file_printf(ms, ",") == -1)
319 							return -1;
320 				}
321 				if (n_nel)
322 					if (file_printf(ms, " NEL") == -1)
323 						return -1;
324 			}
325 
326 			if (file_printf(ms, " line terminators") == -1)
327 				return -1;
328 		}
329 
330 		if (has_escapes)
331 			if (file_printf(ms, ", with escape sequences") == -1)
332 				return -1;
333 		if (has_backspace)
334 			if (file_printf(ms, ", with overstriking") == -1)
335 				return -1;
336 	}
337 
338 	return 1;
339 }
340 
341 private int
ascmatch(const unsigned char * s,const unichar * us,size_t ulen)342 ascmatch(const unsigned char *s, const unichar *us, size_t ulen)
343 {
344 	size_t i;
345 
346 	for (i = 0; i < ulen; i++) {
347 		if (s[i] != us[i])
348 			return 0;
349 	}
350 
351 	if (s[i])
352 		return 0;
353 	else
354 		return 1;
355 }
356 
357 /*
358  * This table reflects a particular philosophy about what constitutes
359  * "text," and there is room for disagreement about it.
360  *
361  * Version 3.31 of the file command considered a file to be ASCII if
362  * each of its characters was approved by either the isascii() or
363  * isalpha() function.  On most systems, this would mean that any
364  * file consisting only of characters in the range 0x00 ... 0x7F
365  * would be called ASCII text, but many systems might reasonably
366  * consider some characters outside this range to be alphabetic,
367  * so the file command would call such characters ASCII.  It might
368  * have been more accurate to call this "considered textual on the
369  * local system" than "ASCII."
370  *
371  * It considered a file to be "International language text" if each
372  * of its characters was either an ASCII printing character (according
373  * to the real ASCII standard, not the above test), a character in
374  * the range 0x80 ... 0xFF, or one of the following control characters:
375  * backspace, tab, line feed, vertical tab, form feed, carriage return,
376  * escape.  No attempt was made to determine the language in which files
377  * of this type were written.
378  *
379  *
380  * The table below considers a file to be ASCII if all of its characters
381  * are either ASCII printing characters (again, according to the X3.4
382  * standard, not isascii()) or any of the following controls: bell,
383  * backspace, tab, line feed, form feed, carriage return, esc, nextline.
384  *
385  * I include bell because some programs (particularly shell scripts)
386  * use it literally, even though it is rare in normal text.  I exclude
387  * vertical tab because it never seems to be used in real text.  I also
388  * include, with hesitation, the X3.64/ECMA-43 control nextline (0x85),
389  * because that's what the dd EBCDIC->ASCII table maps the EBCDIC newline
390  * character to.  It might be more appropriate to include it in the 8859
391  * set instead of the ASCII set, but it's got to be included in *something*
392  * we recognize or EBCDIC files aren't going to be considered textual.
393  * Some old Unix source files use SO/SI (^N/^O) to shift between Greek
394  * and Latin characters, so these should possibly be allowed.  But they
395  * make a real mess on VT100-style displays if they're not paired properly,
396  * so we are probably better off not calling them text.
397  *
398  * A file is considered to be ISO-8859 text if its characters are all
399  * either ASCII, according to the above definition, or printing characters
400  * from the ISO-8859 8-bit extension, characters 0xA0 ... 0xFF.
401  *
402  * Finally, a file is considered to be international text from some other
403  * character code if its characters are all either ISO-8859 (according to
404  * the above definition) or characters in the range 0x80 ... 0x9F, which
405  * ISO-8859 considers to be control characters but the IBM PC and Macintosh
406  * consider to be printing characters.
407  */
408 
409 #define F 0   /* character never appears in text */
410 #define T 1   /* character appears in plain ASCII text */
411 #define I 2   /* character appears in ISO-8859 text */
412 #define X 3   /* character appears in non-ISO extended ASCII (Mac, IBM PC) */
413 
414 private char text_chars[256] = {
415 	/*                  BEL BS HT LF    FF CR    */
416 	F, F, F, F, F, F, F, T, T, T, T, F, T, T, F, F,  /* 0x0X */
417         /*                              ESC          */
418 	F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F,  /* 0x1X */
419 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x2X */
420 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x3X */
421 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x4X */
422 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x5X */
423 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x6X */
424 	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F,  /* 0x7X */
425 	/*            NEL                            */
426 	X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X,  /* 0x8X */
427 	X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X,  /* 0x9X */
428 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xaX */
429 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xbX */
430 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xcX */
431 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xdX */
432 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xeX */
433 	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I   /* 0xfX */
434 };
435 
436 private int
looks_ascii(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)437 looks_ascii(const unsigned char *buf, size_t nbytes, unichar *ubuf,
438     size_t *ulen)
439 {
440 	size_t i;
441 
442 	*ulen = 0;
443 
444 	for (i = 0; i < nbytes; i++) {
445 		int t = text_chars[buf[i]];
446 
447 		if (t != T)
448 			return 0;
449 
450 		ubuf[(*ulen)++] = buf[i];
451 	}
452 
453 	return 1;
454 }
455 
456 private int
looks_latin1(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)457 looks_latin1(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
458 {
459 	size_t i;
460 
461 	*ulen = 0;
462 
463 	for (i = 0; i < nbytes; i++) {
464 		int t = text_chars[buf[i]];
465 
466 		if (t != T && t != I)
467 			return 0;
468 
469 		ubuf[(*ulen)++] = buf[i];
470 	}
471 
472 	return 1;
473 }
474 
475 private int
looks_extended(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)476 looks_extended(const unsigned char *buf, size_t nbytes, unichar *ubuf,
477     size_t *ulen)
478 {
479 	size_t i;
480 
481 	*ulen = 0;
482 
483 	for (i = 0; i < nbytes; i++) {
484 		int t = text_chars[buf[i]];
485 
486 		if (t != T && t != I && t != X)
487 			return 0;
488 
489 		ubuf[(*ulen)++] = buf[i];
490 	}
491 
492 	return 1;
493 }
494 
495 private int
looks_utf8(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)496 looks_utf8(const unsigned char *buf, size_t nbytes, unichar *ubuf, size_t *ulen)
497 {
498 	size_t i;
499 	int n;
500 	unichar c;
501 	int gotone = 0;
502 
503 	*ulen = 0;
504 
505 	for (i = 0; i < nbytes; i++) {
506 		if ((buf[i] & 0x80) == 0) {	   /* 0xxxxxxx is plain ASCII */
507 			/*
508 			 * Even if the whole file is valid UTF-8 sequences,
509 			 * still reject it if it uses weird control characters.
510 			 */
511 
512 			if (text_chars[buf[i]] != T)
513 				return 0;
514 
515 			ubuf[(*ulen)++] = buf[i];
516 		} else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */
517 			return 0;
518 		} else {			   /* 11xxxxxx begins UTF-8 */
519 			int following;
520 
521 			if ((buf[i] & 0x20) == 0) {		/* 110xxxxx */
522 				c = buf[i] & 0x1f;
523 				following = 1;
524 			} else if ((buf[i] & 0x10) == 0) {	/* 1110xxxx */
525 				c = buf[i] & 0x0f;
526 				following = 2;
527 			} else if ((buf[i] & 0x08) == 0) {	/* 11110xxx */
528 				c = buf[i] & 0x07;
529 				following = 3;
530 			} else if ((buf[i] & 0x04) == 0) {	/* 111110xx */
531 				c = buf[i] & 0x03;
532 				following = 4;
533 			} else if ((buf[i] & 0x02) == 0) {	/* 1111110x */
534 				c = buf[i] & 0x01;
535 				following = 5;
536 			} else
537 				return 0;
538 
539 			for (n = 0; n < following; n++) {
540 				i++;
541 				if (i >= nbytes)
542 					goto done;
543 
544 				if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40))
545 					return 0;
546 
547 				c = (c << 6) + (buf[i] & 0x3f);
548 			}
549 
550 			ubuf[(*ulen)++] = c;
551 			gotone = 1;
552 		}
553 	}
554 done:
555 	return gotone;   /* don't claim it's UTF-8 if it's all 7-bit */
556 }
557 
558 private int
looks_unicode(const unsigned char * buf,size_t nbytes,unichar * ubuf,size_t * ulen)559 looks_unicode(const unsigned char *buf, size_t nbytes, unichar *ubuf,
560     size_t *ulen)
561 {
562 	int bigend;
563 	size_t i;
564 
565 	if (nbytes < 2)
566 		return 0;
567 
568 	if (buf[0] == 0xff && buf[1] == 0xfe)
569 		bigend = 0;
570 	else if (buf[0] == 0xfe && buf[1] == 0xff)
571 		bigend = 1;
572 	else
573 		return 0;
574 
575 	*ulen = 0;
576 
577 	for (i = 2; i + 1 < nbytes; i += 2) {
578 		/* XXX fix to properly handle chars > 65536 */
579 
580 		if (bigend)
581 			ubuf[(*ulen)++] = buf[i + 1] + 256 * buf[i];
582 		else
583 			ubuf[(*ulen)++] = buf[i] + 256 * buf[i + 1];
584 
585 		if (ubuf[*ulen - 1] == 0xfffe)
586 			return 0;
587 		if (ubuf[*ulen - 1] < 128 &&
588 		    text_chars[(size_t)ubuf[*ulen - 1]] != T)
589 			return 0;
590 	}
591 
592 	return 1 + bigend;
593 }
594 
595 #undef F
596 #undef T
597 #undef I
598 #undef X
599 
600 /*
601  * This table maps each EBCDIC character to an (8-bit extended) ASCII
602  * character, as specified in the rationale for the dd(1) command in
603  * draft 11.2 (September, 1991) of the POSIX P1003.2 standard.
604  *
605  * Unfortunately it does not seem to correspond exactly to any of the
606  * five variants of EBCDIC documented in IBM's _Enterprise Systems
607  * Architecture/390: Principles of Operation_, SA22-7201-06, Seventh
608  * Edition, July, 1999, pp. I-1 - I-4.
609  *
610  * Fortunately, though, all versions of EBCDIC, including this one, agree
611  * on most of the printing characters that also appear in (7-bit) ASCII.
612  * Of these, only '|', '!', '~', '^', '[', and ']' are in question at all.
613  *
614  * Fortunately too, there is general agreement that codes 0x00 through
615  * 0x3F represent control characters, 0x41 a nonbreaking space, and the
616  * remainder printing characters.
617  *
618  * This is sufficient to allow us to identify EBCDIC text and to distinguish
619  * between old-style and internationalized examples of text.
620  */
621 
622 private unsigned char ebcdic_to_ascii[] = {
623   0,   1,   2,   3, 156,   9, 134, 127, 151, 141, 142,  11,  12,  13,  14,  15,
624  16,  17,  18,  19, 157, 133,   8, 135,  24,  25, 146, 143,  28,  29,  30,  31,
625 128, 129, 130, 131, 132,  10,  23,  27, 136, 137, 138, 139, 140,   5,   6,   7,
626 144, 145,  22, 147, 148, 149, 150,   4, 152, 153, 154, 155,  20,  21, 158,  26,
627 ' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|',
628 '&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~',
629 '-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?',
630 186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"',
631 195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201,
632 202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208,
633 209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215,
634 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231,
635 '{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237,
636 '}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243,
637 '\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249,
638 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255
639 };
640 
641 #ifdef notdef
642 /*
643  * The following EBCDIC-to-ASCII table may relate more closely to reality,
644  * or at least to modern reality.  It comes from
645  *
646  *   http://ftp.s390.ibm.com/products/oe/bpxqp9.html
647  *
648  * and maps the characters of EBCDIC code page 1047 (the code used for
649  * Unix-derived software on IBM's 390 systems) to the corresponding
650  * characters from ISO 8859-1.
651  *
652  * If this table is used instead of the above one, some of the special
653  * cases for the NEL character can be taken out of the code.
654  */
655 
656 private unsigned char ebcdic_1047_to_8859[] = {
657 0x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F,
658 0x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F,
659 0x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07,
660 0x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A,
661 0x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C,
662 0x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E,
663 0x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F,
664 0xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22,
665 0xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1,
666 0xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4,
667 0xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE,
668 0xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7,
669 0x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5,
670 0x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF,
671 0x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5,
672 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F
673 };
674 #endif
675 
676 /*
677  * Copy buf[0 ... nbytes-1] into out[], translating EBCDIC to ASCII.
678  */
679 private void
from_ebcdic(const unsigned char * buf,size_t nbytes,unsigned char * out)680 from_ebcdic(const unsigned char *buf, size_t nbytes, unsigned char *out)
681 {
682 	size_t i;
683 
684 	for (i = 0; i < nbytes; i++) {
685 		out[i] = ebcdic_to_ascii[buf[i]];
686 	}
687 }
688