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 1.42 2022/12/26 17:31:14 christos Exp $") 39 #endif /* lint */ 40 41 #include "magic.h" 42 #include <string.h> 43 #include <stdlib.h> 44 45 46 file_private int looks_ascii(const unsigned char *, size_t, file_unichar_t *, 47 size_t *); 48 file_private int looks_utf8_with_BOM(const unsigned char *, size_t, file_unichar_t *, 49 size_t *); 50 file_private int looks_utf7(const unsigned char *, size_t, file_unichar_t *, 51 size_t *); 52 file_private int looks_ucs16(const unsigned char *, size_t, file_unichar_t *, 53 size_t *); 54 file_private int looks_ucs32(const unsigned char *, size_t, file_unichar_t *, 55 size_t *); 56 file_private int looks_latin1(const unsigned char *, size_t, file_unichar_t *, 57 size_t *); 58 file_private int looks_extended(const unsigned char *, size_t, file_unichar_t *, 59 size_t *); 60 file_private void from_ebcdic(const unsigned char *, size_t, unsigned char *); 61 62 #ifdef DEBUG_ENCODING 63 #define DPRINTF(a) printf a 64 #else 65 #define DPRINTF(a) 66 #endif 67 68 /* 69 * Try to determine whether text is in some character code we can 70 * identify. Each of these tests, if it succeeds, will leave 71 * the text converted into one-file_unichar_t-per-character Unicode in 72 * ubuf, and the number of characters converted in ulen. 73 */ 74 file_protected int 75 file_encoding(struct magic_set *ms, const struct buffer *b, 76 file_unichar_t **ubuf, size_t *ulen, const char **code, 77 const char **code_mime, const char **type) 78 { 79 const unsigned char *buf = CAST(const unsigned char *, b->fbuf); 80 size_t nbytes = b->flen; 81 size_t mlen; 82 int rv = 1, ucs_type; 83 file_unichar_t *udefbuf; 84 size_t udeflen; 85 86 if (ubuf == NULL) 87 ubuf = &udefbuf; 88 if (ulen == NULL) 89 ulen = &udeflen; 90 91 *type = "text"; 92 *ulen = 0; 93 *code = "unknown"; 94 *code_mime = "binary"; 95 96 if (nbytes > ms->encoding_max) 97 nbytes = ms->encoding_max; 98 99 mlen = (nbytes + 1) * sizeof((*ubuf)[0]); 100 *ubuf = CAST(file_unichar_t *, calloc(CAST(size_t, 1), mlen)); 101 if (*ubuf == NULL) { 102 file_oomem(ms, mlen); 103 goto done; 104 } 105 if (looks_ascii(buf, nbytes, *ubuf, ulen)) { 106 if (looks_utf7(buf, nbytes, *ubuf, ulen) > 0) { 107 DPRINTF(("utf-7 %" SIZE_T_FORMAT "u\n", *ulen)); 108 *code = "Unicode text, UTF-7"; 109 *code_mime = "utf-7"; 110 } else { 111 DPRINTF(("ascii %" SIZE_T_FORMAT "u\n", *ulen)); 112 *code = "ASCII"; 113 *code_mime = "us-ascii"; 114 } 115 } else if (looks_utf8_with_BOM(buf, nbytes, *ubuf, ulen) > 0) { 116 DPRINTF(("utf8/bom %" SIZE_T_FORMAT "u\n", *ulen)); 117 *code = "Unicode text, UTF-8 (with BOM)"; 118 *code_mime = "utf-8"; 119 } else if (file_looks_utf8(buf, nbytes, *ubuf, ulen) > 1) { 120 DPRINTF(("utf8 %" SIZE_T_FORMAT "u\n", *ulen)); 121 *code = "Unicode text, UTF-8"; 122 *code_mime = "utf-8"; 123 } else if ((ucs_type = looks_ucs32(buf, nbytes, *ubuf, ulen)) != 0) { 124 if (ucs_type == 1) { 125 *code = "Unicode text, UTF-32, little-endian"; 126 *code_mime = "utf-32le"; 127 } else { 128 *code = "Unicode text, UTF-32, big-endian"; 129 *code_mime = "utf-32be"; 130 } 131 DPRINTF(("ucs32 %" SIZE_T_FORMAT "u\n", *ulen)); 132 } else if ((ucs_type = looks_ucs16(buf, nbytes, *ubuf, ulen)) != 0) { 133 if (ucs_type == 1) { 134 *code = "Unicode text, UTF-16, little-endian"; 135 *code_mime = "utf-16le"; 136 } else { 137 *code = "Unicode text, UTF-16, big-endian"; 138 *code_mime = "utf-16be"; 139 } 140 DPRINTF(("ucs16 %" SIZE_T_FORMAT "u\n", *ulen)); 141 } else if (looks_latin1(buf, nbytes, *ubuf, ulen)) { 142 DPRINTF(("latin1 %" SIZE_T_FORMAT "u\n", *ulen)); 143 *code = "ISO-8859"; 144 *code_mime = "iso-8859-1"; 145 } else if (looks_extended(buf, nbytes, *ubuf, ulen)) { 146 DPRINTF(("extended %" SIZE_T_FORMAT "u\n", *ulen)); 147 *code = "Non-ISO extended-ASCII"; 148 *code_mime = "unknown-8bit"; 149 } else { 150 unsigned char *nbuf; 151 152 mlen = (nbytes + 1) * sizeof(nbuf[0]); 153 if ((nbuf = CAST(unsigned char *, malloc(mlen))) == NULL) { 154 file_oomem(ms, mlen); 155 goto done; 156 } 157 from_ebcdic(buf, nbytes, nbuf); 158 159 if (looks_ascii(nbuf, nbytes, *ubuf, ulen)) { 160 DPRINTF(("ebcdic %" SIZE_T_FORMAT "u\n", *ulen)); 161 *code = "EBCDIC"; 162 *code_mime = "ebcdic"; 163 } else if (looks_latin1(nbuf, nbytes, *ubuf, ulen)) { 164 DPRINTF(("ebcdic/international %" SIZE_T_FORMAT "u\n", 165 *ulen)); 166 *code = "International EBCDIC"; 167 *code_mime = "ebcdic"; 168 } else { /* Doesn't look like text at all */ 169 DPRINTF(("binary\n")); 170 rv = 0; 171 *type = "binary"; 172 } 173 free(nbuf); 174 } 175 176 done: 177 if (ubuf == &udefbuf) 178 free(udefbuf); 179 180 return rv; 181 } 182 183 /* 184 * This table reflects a particular philosophy about what constitutes 185 * "text," and there is room for disagreement about it. 186 * 187 * Version 3.31 of the file command considered a file to be ASCII if 188 * each of its characters was approved by either the isascii() or 189 * isalpha() function. On most systems, this would mean that any 190 * file consisting only of characters in the range 0x00 ... 0x7F 191 * would be called ASCII text, but many systems might reasonably 192 * consider some characters outside this range to be alphabetic, 193 * so the file command would call such characters ASCII. It might 194 * have been more accurate to call this "considered textual on the 195 * local system" than "ASCII." 196 * 197 * It considered a file to be "International language text" if each 198 * of its characters was either an ASCII printing character (according 199 * to the real ASCII standard, not the above test), a character in 200 * the range 0x80 ... 0xFF, or one of the following control characters: 201 * backspace, tab, line feed, vertical tab, form feed, carriage return, 202 * escape. No attempt was made to determine the language in which files 203 * of this type were written. 204 * 205 * 206 * The table below considers a file to be ASCII if all of its characters 207 * are either ASCII printing characters (again, according to the X3.4 208 * standard, not isascii()) or any of the following controls: bell, 209 * backspace, tab, line feed, form feed, carriage return, esc, nextline. 210 * 211 * I include bell because some programs (particularly shell scripts) 212 * use it literally, even though it is rare in normal text. I exclude 213 * vertical tab because it never seems to be used in real text. I also 214 * include, with hesitation, the X3.64/ECMA-43 control nextline (0x85), 215 * because that's what the dd EBCDIC->ASCII table maps the EBCDIC newline 216 * character to. It might be more appropriate to include it in the 8859 217 * set instead of the ASCII set, but it's got to be included in *something* 218 * we recognize or EBCDIC files aren't going to be considered textual. 219 * Some old Unix source files use SO/SI (^N/^O) to shift between Greek 220 * and Latin characters, so these should possibly be allowed. But they 221 * make a real mess on VT100-style displays if they're not paired properly, 222 * so we are probably better off not calling them text. 223 * 224 * A file is considered to be ISO-8859 text if its characters are all 225 * either ASCII, according to the above definition, or printing characters 226 * from the ISO-8859 8-bit extension, characters 0xA0 ... 0xFF. 227 * 228 * Finally, a file is considered to be international text from some other 229 * character code if its characters are all either ISO-8859 (according to 230 * the above definition) or characters in the range 0x80 ... 0x9F, which 231 * ISO-8859 considers to be control characters but the IBM PC and Macintosh 232 * consider to be printing characters. 233 */ 234 235 #define F 0 /* character never appears in text */ 236 #define T 1 /* character appears in plain ASCII text */ 237 #define I 2 /* character appears in ISO-8859 text */ 238 #define X 3 /* character appears in non-ISO extended ASCII (Mac, IBM PC) */ 239 240 file_private char text_chars[256] = { 241 /* BEL BS HT LF VT FF CR */ 242 F, F, F, F, F, F, F, T, T, T, T, T, T, T, F, F, /* 0x0X */ 243 /* ESC */ 244 F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F, /* 0x1X */ 245 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x2X */ 246 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x3X */ 247 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x4X */ 248 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x5X */ 249 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x6X */ 250 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, /* 0x7X */ 251 /* NEL */ 252 X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X, /* 0x8X */ 253 X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, /* 0x9X */ 254 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xaX */ 255 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xbX */ 256 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xcX */ 257 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xdX */ 258 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xeX */ 259 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I /* 0xfX */ 260 }; 261 262 #define LOOKS(NAME, COND) \ 263 file_private int \ 264 looks_ ## NAME(const unsigned char *buf, size_t nbytes, file_unichar_t *ubuf, \ 265 size_t *ulen) \ 266 { \ 267 size_t i; \ 268 \ 269 *ulen = 0; \ 270 \ 271 for (i = 0; i < nbytes; i++) { \ 272 int t = text_chars[buf[i]]; \ 273 \ 274 if (COND) \ 275 return 0; \ 276 \ 277 ubuf[(*ulen)++] = buf[i]; \ 278 } \ 279 return 1; \ 280 } 281 282 LOOKS(ascii, t != T) 283 LOOKS(latin1, t != T && t != I) 284 LOOKS(extended, t != T && t != I && t != X) 285 286 /* 287 * Decide whether some text looks like UTF-8. Returns: 288 * 289 * -1: invalid UTF-8 290 * 0: uses odd control characters, so doesn't look like text 291 * 1: 7-bit text 292 * 2: definitely UTF-8 text (valid high-bit set bytes) 293 * 294 * If ubuf is non-NULL on entry, text is decoded into ubuf, *ulen; 295 * ubuf must be big enough! 296 */ 297 298 // from: https://golang.org/src/unicode/utf8/utf8.go 299 300 #define XX 0xF1 // invalid: size 1 301 #define AS 0xF0 // ASCII: size 1 302 #define S1 0x02 // accept 0, size 2 303 #define S2 0x13 // accept 1, size 3 304 #define S3 0x03 // accept 0, size 3 305 #define S4 0x23 // accept 2, size 3 306 #define S5 0x34 // accept 3, size 4 307 #define S6 0x04 // accept 0, size 4 308 #define S7 0x44 // accept 4, size 4 309 310 #define LOCB 0x80 311 #define HICB 0xBF 312 313 // first is information about the first byte in a UTF-8 sequence. 314 static const uint8_t first[] = { 315 // 1 2 3 4 5 6 7 8 9 A B C D E F 316 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x00-0x0F 317 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x10-0x1F 318 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x20-0x2F 319 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x30-0x3F 320 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x40-0x4F 321 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x50-0x5F 322 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x60-0x6F 323 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x70-0x7F 324 // 1 2 3 4 5 6 7 8 9 A B C D E F 325 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0x80-0x8F 326 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0x90-0x9F 327 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0xA0-0xAF 328 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0xB0-0xBF 329 XX, XX, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, // 0xC0-0xCF 330 S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, // 0xD0-0xDF 331 S2, S3, S3, S3, S3, S3, S3, S3, S3, S3, S3, S3, S3, S4, S3, S3, // 0xE0-0xEF 332 S5, S6, S6, S6, S7, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0xF0-0xFF 333 }; 334 335 // acceptRange gives the range of valid values for the second byte in a UTF-8 336 // sequence. 337 struct accept_range { 338 uint8_t lo; // lowest value for second byte. 339 uint8_t hi; // highest value for second byte. 340 } accept_ranges[16] = { 341 // acceptRanges has size 16 to avoid bounds checks in the code that uses it. 342 { LOCB, HICB }, 343 { 0xA0, HICB }, 344 { LOCB, 0x9F }, 345 { 0x90, HICB }, 346 { LOCB, 0x8F }, 347 }; 348 349 file_protected int 350 file_looks_utf8(const unsigned char *buf, size_t nbytes, file_unichar_t *ubuf, 351 size_t *ulen) 352 { 353 size_t i; 354 int n; 355 file_unichar_t c; 356 int gotone = 0, ctrl = 0; 357 358 if (ubuf) 359 *ulen = 0; 360 361 for (i = 0; i < nbytes; i++) { 362 if ((buf[i] & 0x80) == 0) { /* 0xxxxxxx is plain ASCII */ 363 /* 364 * Even if the whole file is valid UTF-8 sequences, 365 * still reject it if it uses weird control characters. 366 */ 367 368 if (text_chars[buf[i]] != T) 369 ctrl = 1; 370 371 if (ubuf) 372 ubuf[(*ulen)++] = buf[i]; 373 } else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */ 374 return -1; 375 } else { /* 11xxxxxx begins UTF-8 */ 376 int following; 377 uint8_t x = first[buf[i]]; 378 const struct accept_range *ar = 379 &accept_ranges[(unsigned int)x >> 4]; 380 if (x == XX) 381 return -1; 382 383 if ((buf[i] & 0x20) == 0) { /* 110xxxxx */ 384 c = buf[i] & 0x1f; 385 following = 1; 386 } else if ((buf[i] & 0x10) == 0) { /* 1110xxxx */ 387 c = buf[i] & 0x0f; 388 following = 2; 389 } else if ((buf[i] & 0x08) == 0) { /* 11110xxx */ 390 c = buf[i] & 0x07; 391 following = 3; 392 } else if ((buf[i] & 0x04) == 0) { /* 111110xx */ 393 c = buf[i] & 0x03; 394 following = 4; 395 } else if ((buf[i] & 0x02) == 0) { /* 1111110x */ 396 c = buf[i] & 0x01; 397 following = 5; 398 } else 399 return -1; 400 401 for (n = 0; n < following; n++) { 402 i++; 403 if (i >= nbytes) 404 goto done; 405 406 if (n == 0 && 407 (buf[i] < ar->lo || buf[i] > ar->hi)) 408 return -1; 409 410 if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40)) 411 return -1; 412 413 c = (c << 6) + (buf[i] & 0x3f); 414 } 415 416 if (ubuf) 417 ubuf[(*ulen)++] = c; 418 gotone = 1; 419 } 420 } 421 done: 422 return ctrl ? 0 : (gotone ? 2 : 1); 423 } 424 425 /* 426 * Decide whether some text looks like UTF-8 with BOM. If there is no 427 * BOM, return -1; otherwise return the result of looks_utf8 on the 428 * rest of the text. 429 */ 430 file_private int 431 looks_utf8_with_BOM(const unsigned char *buf, size_t nbytes, 432 file_unichar_t *ubuf, size_t *ulen) 433 { 434 if (nbytes > 3 && buf[0] == 0xef && buf[1] == 0xbb && buf[2] == 0xbf) 435 return file_looks_utf8(buf + 3, nbytes - 3, ubuf, ulen); 436 else 437 return -1; 438 } 439 440 file_private int 441 looks_utf7(const unsigned char *buf, size_t nbytes, file_unichar_t *ubuf, 442 size_t *ulen) 443 { 444 if (nbytes > 4 && buf[0] == '+' && buf[1] == '/' && buf[2] == 'v') 445 switch (buf[3]) { 446 case '8': 447 case '9': 448 case '+': 449 case '/': 450 if (ubuf) 451 *ulen = 0; 452 return 1; 453 default: 454 return -1; 455 } 456 else 457 return -1; 458 } 459 460 #define UCS16_NOCHAR(c) ((c) >= 0xfdd0 && (c) <= 0xfdef) 461 #define UCS16_HISURR(c) ((c) >= 0xd800 && (c) <= 0xdbff) 462 #define UCS16_LOSURR(c) ((c) >= 0xdc00 && (c) <= 0xdfff) 463 464 file_private int 465 looks_ucs16(const unsigned char *bf, size_t nbytes, file_unichar_t *ubf, 466 size_t *ulen) 467 { 468 int bigend; 469 uint32_t hi; 470 size_t i; 471 472 if (nbytes < 2) 473 return 0; 474 475 if (bf[0] == 0xff && bf[1] == 0xfe) 476 bigend = 0; 477 else if (bf[0] == 0xfe && bf[1] == 0xff) 478 bigend = 1; 479 else 480 return 0; 481 482 *ulen = 0; 483 hi = 0; 484 485 for (i = 2; i + 1 < nbytes; i += 2) { 486 uint32_t uc; 487 488 if (bigend) 489 uc = CAST(uint32_t, 490 bf[i + 1] | (CAST(file_unichar_t, bf[i]) << 8)); 491 else 492 uc = CAST(uint32_t, 493 bf[i] | (CAST(file_unichar_t, bf[i + 1]) << 8)); 494 495 uc &= 0xffff; 496 497 switch (uc) { 498 case 0xfffe: 499 case 0xffff: 500 return 0; 501 default: 502 if (UCS16_NOCHAR(uc)) 503 return 0; 504 break; 505 } 506 if (hi) { 507 if (!UCS16_LOSURR(uc)) 508 return 0; 509 uc = 0x10000 + 0x400 * (hi - 1) + (uc - 0xdc00); 510 hi = 0; 511 } 512 if (uc < 128 && text_chars[CAST(size_t, uc)] != T) 513 return 0; 514 ubf[(*ulen)++] = uc; 515 if (UCS16_HISURR(uc)) 516 hi = uc - 0xd800 + 1; 517 if (UCS16_LOSURR(uc)) 518 return 0; 519 } 520 521 return 1 + bigend; 522 } 523 524 file_private int 525 looks_ucs32(const unsigned char *bf, size_t nbytes, file_unichar_t *ubf, 526 size_t *ulen) 527 { 528 int bigend; 529 size_t i; 530 531 if (nbytes < 4) 532 return 0; 533 534 if (bf[0] == 0xff && bf[1] == 0xfe && bf[2] == 0 && bf[3] == 0) 535 bigend = 0; 536 else if (bf[0] == 0 && bf[1] == 0 && bf[2] == 0xfe && bf[3] == 0xff) 537 bigend = 1; 538 else 539 return 0; 540 541 *ulen = 0; 542 543 for (i = 4; i + 3 < nbytes; i += 4) { 544 /* XXX fix to properly handle chars > 65536 */ 545 546 if (bigend) 547 ubf[(*ulen)++] = CAST(file_unichar_t, bf[i + 3]) 548 | (CAST(file_unichar_t, bf[i + 2]) << 8) 549 | (CAST(file_unichar_t, bf[i + 1]) << 16) 550 | (CAST(file_unichar_t, bf[i]) << 24); 551 else 552 ubf[(*ulen)++] = CAST(file_unichar_t, bf[i + 0]) 553 | (CAST(file_unichar_t, bf[i + 1]) << 8) 554 | (CAST(file_unichar_t, bf[i + 2]) << 16) 555 | (CAST(file_unichar_t, bf[i + 3]) << 24); 556 557 if (ubf[*ulen - 1] == 0xfffe) 558 return 0; 559 if (ubf[*ulen - 1] < 128 && 560 text_chars[CAST(size_t, ubf[*ulen - 1])] != T) 561 return 0; 562 } 563 564 return 1 + bigend; 565 } 566 #undef F 567 #undef T 568 #undef I 569 #undef X 570 571 /* 572 * This table maps each EBCDIC character to an (8-bit extended) ASCII 573 * character, as specified in the rationale for the dd(1) command in 574 * draft 11.2 (September, 1991) of the POSIX P1003.2 standard. 575 * 576 * Unfortunately it does not seem to correspond exactly to any of the 577 * five variants of EBCDIC documented in IBM's _Enterprise Systems 578 * Architecture/390: Principles of Operation_, SA22-7201-06, Seventh 579 * Edition, July, 1999, pp. I-1 - I-4. 580 * 581 * Fortunately, though, all versions of EBCDIC, including this one, agree 582 * on most of the printing characters that also appear in (7-bit) ASCII. 583 * Of these, only '|', '!', '~', '^', '[', and ']' are in question at all. 584 * 585 * Fortunately too, there is general agreement that codes 0x00 through 586 * 0x3F represent control characters, 0x41 a nonbreaking space, and the 587 * remainder printing characters. 588 * 589 * This is sufficient to allow us to identify EBCDIC text and to distinguish 590 * between old-style and internationalized examples of text. 591 */ 592 593 file_private unsigned char ebcdic_to_ascii[] = { 594 0, 1, 2, 3, 156, 9, 134, 127, 151, 141, 142, 11, 12, 13, 14, 15, 595 16, 17, 18, 19, 157, 133, 8, 135, 24, 25, 146, 143, 28, 29, 30, 31, 596 128, 129, 130, 131, 132, 10, 23, 27, 136, 137, 138, 139, 140, 5, 6, 7, 597 144, 145, 22, 147, 148, 149, 150, 4, 152, 153, 154, 155, 20, 21, 158, 26, 598 ' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|', 599 '&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~', 600 '-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?', 601 186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"', 602 195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201, 603 202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208, 604 209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215, 605 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231, 606 '{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237, 607 '}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243, 608 '\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249, 609 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255 610 }; 611 612 #ifdef notdef 613 /* 614 * The following EBCDIC-to-ASCII table may relate more closely to reality, 615 * or at least to modern reality. It comes from 616 * 617 * http://ftp.s390.ibm.com/products/oe/bpxqp9.html 618 * 619 * and maps the characters of EBCDIC code page 1047 (the code used for 620 * Unix-derived software on IBM's 390 systems) to the corresponding 621 * characters from ISO 8859-1. 622 * 623 * If this table is used instead of the above one, some of the special 624 * cases for the NEL character can be taken out of the code. 625 */ 626 627 file_private unsigned char ebcdic_1047_to_8859[] = { 628 0x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F, 629 0x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F, 630 0x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07, 631 0x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A, 632 0x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C, 633 0x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E, 634 0x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F, 635 0xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22, 636 0xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1, 637 0xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4, 638 0xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE, 639 0xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7, 640 0x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5, 641 0x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF, 642 0x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5, 643 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F 644 }; 645 #endif 646 647 /* 648 * Copy buf[0 ... nbytes-1] into out[], translating EBCDIC to ASCII. 649 */ 650 file_private void 651 from_ebcdic(const unsigned char *buf, size_t nbytes, unsigned char *out) 652 { 653 size_t i; 654 655 for (i = 0; i < nbytes; i++) { 656 out[i] = ebcdic_to_ascii[buf[i]]; 657 } 658 } 659