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 1.44 2024/12/26 18:41:27 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 /* 241 * SUB (substitute character ^Z) was used as EOF in DOS and early Windows 242 * NEL (next line 0x85) is considered in ECMAScript as whitespace 243 */ 244 file_private char text_chars[256] = { 245 /* BEL BS HT LF VT FF CR */ 246 F, F, F, F, F, F, F, T, T, T, T, T, T, T, F, F, /* 0x0X */ 247 /* SUB ESC */ 248 F, F, F, F, F, F, F, F, F, F, T, T, F, F, F, F, /* 0x1X */ 249 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x2X */ 250 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x3X */ 251 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x4X */ 252 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x5X */ 253 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, /* 0x6X */ 254 T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F, /* 0x7X */ 255 /* NEL */ 256 X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X, /* 0x8X */ 257 X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, /* 0x9X */ 258 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xaX */ 259 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xbX */ 260 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xcX */ 261 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xdX */ 262 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, /* 0xeX */ 263 I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I /* 0xfX */ 264 }; 265 266 #define LOOKS(NAME, COND) \ 267 file_private int \ 268 looks_ ## NAME(const unsigned char *buf, size_t nbytes, file_unichar_t *ubuf, \ 269 size_t *ulen) \ 270 { \ 271 size_t i; \ 272 \ 273 *ulen = 0; \ 274 \ 275 for (i = 0; i < nbytes; i++) { \ 276 int t = text_chars[buf[i]]; \ 277 \ 278 if (COND) \ 279 return 0; \ 280 \ 281 ubuf[(*ulen)++] = buf[i]; \ 282 } \ 283 return 1; \ 284 } 285 286 LOOKS(ascii, t != T) 287 LOOKS(latin1, t != T && t != I) 288 LOOKS(extended, t != T && t != I && t != X) 289 290 /* 291 * Decide whether some text looks like UTF-8. Returns: 292 * 293 * -1: invalid UTF-8 294 * 0: uses odd control characters, so doesn't look like text 295 * 1: 7-bit text 296 * 2: definitely UTF-8 text (valid high-bit set bytes) 297 * 298 * If ubuf is non-NULL on entry, text is decoded into ubuf, *ulen; 299 * ubuf must be big enough! 300 */ 301 302 // from: https://golang.org/src/unicode/utf8/utf8.go 303 304 #define XX 0xF1 // invalid: size 1 305 #define AS 0xF0 // ASCII: size 1 306 #define S1 0x02 // accept 0, size 2 307 #define S2 0x13 // accept 1, size 3 308 #define S3 0x03 // accept 0, size 3 309 #define S4 0x23 // accept 2, size 3 310 #define S5 0x34 // accept 3, size 4 311 #define S6 0x04 // accept 0, size 4 312 #define S7 0x44 // accept 4, size 4 313 314 #define LOCB 0x80 315 #define HICB 0xBF 316 317 // first is information about the first byte in a UTF-8 sequence. 318 static const uint8_t first[] = { 319 // 1 2 3 4 5 6 7 8 9 A B C D E F 320 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x00-0x0F 321 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x10-0x1F 322 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x20-0x2F 323 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x30-0x3F 324 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x40-0x4F 325 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x50-0x5F 326 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x60-0x6F 327 AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, AS, // 0x70-0x7F 328 // 1 2 3 4 5 6 7 8 9 A B C D E F 329 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0x80-0x8F 330 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0x90-0x9F 331 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0xA0-0xAF 332 XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0xB0-0xBF 333 XX, XX, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, // 0xC0-0xCF 334 S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, S1, // 0xD0-0xDF 335 S2, S3, S3, S3, S3, S3, S3, S3, S3, S3, S3, S3, S3, S4, S3, S3, // 0xE0-0xEF 336 S5, S6, S6, S6, S7, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, XX, // 0xF0-0xFF 337 }; 338 339 // acceptRange gives the range of valid values for the second byte in a UTF-8 340 // sequence. 341 static struct accept_range { 342 uint8_t lo; // lowest value for second byte. 343 uint8_t hi; // highest value for second byte. 344 } accept_ranges[16] = { 345 // acceptRanges has size 16 to avoid bounds checks in the code that uses it. 346 { LOCB, HICB }, 347 { 0xA0, HICB }, 348 { LOCB, 0x9F }, 349 { 0x90, HICB }, 350 { LOCB, 0x8F }, 351 }; 352 353 file_protected int 354 file_looks_utf8(const unsigned char *buf, size_t nbytes, file_unichar_t *ubuf, 355 size_t *ulen) 356 { 357 size_t i; 358 int n; 359 file_unichar_t c; 360 int gotone = 0, ctrl = 0; 361 362 if (ubuf) 363 *ulen = 0; 364 365 for (i = 0; i < nbytes; i++) { 366 if ((buf[i] & 0x80) == 0) { /* 0xxxxxxx is plain ASCII */ 367 /* 368 * Even if the whole file is valid UTF-8 sequences, 369 * still reject it if it uses weird control characters. 370 */ 371 372 if (text_chars[buf[i]] != T) 373 ctrl = 1; 374 375 if (ubuf) 376 ubuf[(*ulen)++] = buf[i]; 377 } else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */ 378 return -1; 379 } else { /* 11xxxxxx begins UTF-8 */ 380 int following; 381 uint8_t x = first[buf[i]]; 382 const struct accept_range *ar = 383 &accept_ranges[(unsigned int)x >> 4]; 384 if (x == XX) 385 return -1; 386 387 if ((buf[i] & 0x20) == 0) { /* 110xxxxx */ 388 c = buf[i] & 0x1f; 389 following = 1; 390 } else if ((buf[i] & 0x10) == 0) { /* 1110xxxx */ 391 c = buf[i] & 0x0f; 392 following = 2; 393 } else if ((buf[i] & 0x08) == 0) { /* 11110xxx */ 394 c = buf[i] & 0x07; 395 following = 3; 396 } else if ((buf[i] & 0x04) == 0) { /* 111110xx */ 397 c = buf[i] & 0x03; 398 following = 4; 399 } else if ((buf[i] & 0x02) == 0) { /* 1111110x */ 400 c = buf[i] & 0x01; 401 following = 5; 402 } else 403 return -1; 404 405 for (n = 0; n < following; n++) { 406 i++; 407 if (i >= nbytes) 408 goto done; 409 410 if (n == 0 && 411 (buf[i] < ar->lo || buf[i] > ar->hi)) 412 return -1; 413 414 if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40)) 415 return -1; 416 417 c = (c << 6) + (buf[i] & 0x3f); 418 } 419 420 if (ubuf) 421 ubuf[(*ulen)++] = c; 422 gotone = 1; 423 } 424 } 425 done: 426 return ctrl ? 0 : (gotone ? 2 : 1); 427 } 428 429 /* 430 * Decide whether some text looks like UTF-8 with BOM. If there is no 431 * BOM, return -1; otherwise return the result of looks_utf8 on the 432 * rest of the text. 433 */ 434 file_private int 435 looks_utf8_with_BOM(const unsigned char *buf, size_t nbytes, 436 file_unichar_t *ubuf, size_t *ulen) 437 { 438 if (nbytes > 3 && buf[0] == 0xef && buf[1] == 0xbb && buf[2] == 0xbf) 439 return file_looks_utf8(buf + 3, nbytes - 3, ubuf, ulen); 440 else 441 return -1; 442 } 443 444 file_private int 445 looks_utf7(const unsigned char *buf, size_t nbytes, file_unichar_t *ubuf, 446 size_t *ulen) 447 { 448 if (nbytes > 4 && buf[0] == '+' && buf[1] == '/' && buf[2] == 'v') 449 switch (buf[3]) { 450 case '8': 451 case '9': 452 case '+': 453 case '/': 454 if (ubuf) 455 *ulen = 0; 456 return 1; 457 default: 458 return -1; 459 } 460 else 461 return -1; 462 } 463 464 #define UCS16_NOCHAR(c) ((c) >= 0xfdd0 && (c) <= 0xfdef) 465 #define UCS16_HISURR(c) ((c) >= 0xd800 && (c) <= 0xdbff) 466 #define UCS16_LOSURR(c) ((c) >= 0xdc00 && (c) <= 0xdfff) 467 468 file_private int 469 looks_ucs16(const unsigned char *bf, size_t nbytes, file_unichar_t *ubf, 470 size_t *ulen) 471 { 472 int bigend; 473 uint32_t hi; 474 size_t i; 475 476 if (nbytes < 2) 477 return 0; 478 479 if (bf[0] == 0xff && bf[1] == 0xfe) 480 bigend = 0; 481 else if (bf[0] == 0xfe && bf[1] == 0xff) 482 bigend = 1; 483 else 484 return 0; 485 486 *ulen = 0; 487 hi = 0; 488 489 for (i = 2; i + 1 < nbytes; i += 2) { 490 uint32_t uc; 491 492 if (bigend) 493 uc = CAST(uint32_t, 494 bf[i + 1] | (CAST(file_unichar_t, bf[i]) << 8)); 495 else 496 uc = CAST(uint32_t, 497 bf[i] | (CAST(file_unichar_t, bf[i + 1]) << 8)); 498 499 uc &= 0xffff; 500 501 switch (uc) { 502 case 0xfffe: 503 case 0xffff: 504 return 0; 505 default: 506 if (UCS16_NOCHAR(uc)) 507 return 0; 508 break; 509 } 510 if (hi) { 511 if (!UCS16_LOSURR(uc)) 512 return 0; 513 uc = 0x10000 + 0x400 * (hi - 1) + (uc - 0xdc00); 514 hi = 0; 515 } 516 if (uc < 128 && text_chars[CAST(size_t, uc)] != T) 517 return 0; 518 ubf[(*ulen)++] = uc; 519 if (UCS16_HISURR(uc)) 520 hi = uc - 0xd800 + 1; 521 if (UCS16_LOSURR(uc)) 522 return 0; 523 } 524 525 return 1 + bigend; 526 } 527 528 file_private int 529 looks_ucs32(const unsigned char *bf, size_t nbytes, file_unichar_t *ubf, 530 size_t *ulen) 531 { 532 int bigend; 533 size_t i; 534 535 if (nbytes < 4) 536 return 0; 537 538 if (bf[0] == 0xff && bf[1] == 0xfe && bf[2] == 0 && bf[3] == 0) 539 bigend = 0; 540 else if (bf[0] == 0 && bf[1] == 0 && bf[2] == 0xfe && bf[3] == 0xff) 541 bigend = 1; 542 else 543 return 0; 544 545 *ulen = 0; 546 547 for (i = 4; i + 3 < nbytes; i += 4) { 548 /* XXX fix to properly handle chars > 65536 */ 549 550 if (bigend) 551 ubf[(*ulen)++] = CAST(file_unichar_t, bf[i + 3]) 552 | (CAST(file_unichar_t, bf[i + 2]) << 8) 553 | (CAST(file_unichar_t, bf[i + 1]) << 16) 554 | (CAST(file_unichar_t, bf[i]) << 24); 555 else 556 ubf[(*ulen)++] = CAST(file_unichar_t, bf[i + 0]) 557 | (CAST(file_unichar_t, bf[i + 1]) << 8) 558 | (CAST(file_unichar_t, bf[i + 2]) << 16) 559 | (CAST(file_unichar_t, bf[i + 3]) << 24); 560 561 if (ubf[*ulen - 1] == 0xfffe) 562 return 0; 563 if (ubf[*ulen - 1] < 128 && 564 text_chars[CAST(size_t, ubf[*ulen - 1])] != T) 565 return 0; 566 } 567 568 return 1 + bigend; 569 } 570 #undef F 571 #undef T 572 #undef I 573 #undef X 574 575 /* 576 * This table maps each EBCDIC character to an (8-bit extended) ASCII 577 * character, as specified in the rationale for the dd(1) command in 578 * draft 11.2 (September, 1991) of the POSIX P1003.2 standard. 579 * 580 * Unfortunately it does not seem to correspond exactly to any of the 581 * five variants of EBCDIC documented in IBM's _Enterprise Systems 582 * Architecture/390: Principles of Operation_, SA22-7201-06, Seventh 583 * Edition, July, 1999, pp. I-1 - I-4. 584 * 585 * Fortunately, though, all versions of EBCDIC, including this one, agree 586 * on most of the printing characters that also appear in (7-bit) ASCII. 587 * Of these, only '|', '!', '~', '^', '[', and ']' are in question at all. 588 * 589 * Fortunately too, there is general agreement that codes 0x00 through 590 * 0x3F represent control characters, 0x41 a nonbreaking space, and the 591 * remainder printing characters. 592 * 593 * This is sufficient to allow us to identify EBCDIC text and to distinguish 594 * between old-style and internationalized examples of text. 595 */ 596 597 file_private unsigned char ebcdic_to_ascii[] = { 598 0, 1, 2, 3, 156, 9, 134, 127, 151, 141, 142, 11, 12, 13, 14, 15, 599 16, 17, 18, 19, 157, 133, 8, 135, 24, 25, 146, 143, 28, 29, 30, 31, 600 128, 129, 130, 131, 132, 10, 23, 27, 136, 137, 138, 139, 140, 5, 6, 7, 601 144, 145, 22, 147, 148, 149, 150, 4, 152, 153, 154, 155, 20, 21, 158, 26, 602 ' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|', 603 '&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~', 604 '-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?', 605 186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"', 606 195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201, 607 202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208, 608 209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215, 609 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231, 610 '{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237, 611 '}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243, 612 '\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249, 613 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255 614 }; 615 616 #ifdef notdef 617 /* 618 * The following EBCDIC-to-ASCII table may relate more closely to reality, 619 * or at least to modern reality. It comes from 620 * 621 * http://ftp.s390.ibm.com/products/oe/bpxqp9.html 622 * 623 * and maps the characters of EBCDIC code page 1047 (the code used for 624 * Unix-derived software on IBM's 390 systems) to the corresponding 625 * characters from ISO 8859-1. 626 * 627 * If this table is used instead of the above one, some of the special 628 * cases for the NEL character can be taken out of the code. 629 */ 630 631 file_private unsigned char ebcdic_1047_to_8859[] = { 632 0x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F, 633 0x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F, 634 0x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07, 635 0x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A, 636 0x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C, 637 0x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E, 638 0x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F, 639 0xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22, 640 0xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1, 641 0xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4, 642 0xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE, 643 0xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7, 644 0x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5, 645 0x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF, 646 0x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5, 647 0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F 648 }; 649 #endif 650 651 /* 652 * Copy buf[0 ... nbytes-1] into out[], translating EBCDIC to ASCII. 653 */ 654 file_private void 655 from_ebcdic(const unsigned char *buf, size_t nbytes, unsigned char *out) 656 { 657 size_t i; 658 659 for (i = 0; i < nbytes; i++) { 660 out[i] = ebcdic_to_ascii[buf[i]]; 661 } 662 } 663