a71ece51 |
1 | /* cli.c |
2 | * Greg Cook, 9/Apr/2015 |
3 | */ |
4 | |
5 | /* CRC RevEng, an arbitrary-precision CRC calculator and algorithm finder |
6 | * Copyright (C) 2010, 2011, 2012, 2013, 2014, 2015 Gregory Cook |
7 | * |
8 | * This file is part of CRC RevEng. |
9 | * |
10 | * CRC RevEng is free software: you can redistribute it and/or modify |
11 | * it under the terms of the GNU General Public License as published by |
12 | * the Free Software Foundation, either version 3 of the License, or |
13 | * (at your option) any later version. |
14 | * |
15 | * CRC RevEng is distributed in the hope that it will be useful, |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
18 | * GNU General Public License for more details. |
19 | * |
20 | * You should have received a copy of the GNU General Public License |
21 | * along with CRC RevEng. If not, see <http://www.gnu.org/licenses/>. |
22 | */ |
23 | |
24 | /* 2015-04-03: added -z |
25 | * 2013-09-16: do not search with -M |
26 | * 2013-06-11: uprog() suppresses first progress report |
27 | * 2013-04-22: uprog() prints poly same as mtostr() |
28 | * 2013-02-07: added -q, uprog(), removed -W, R_ODDLY |
29 | * 2012-05-24: -D dumps parameters of all models |
30 | * 2012-03-03: added code to test sort order of model table |
31 | * 2012-02-20: set stdin to binary (MinGW). offer -D if preset unknown. |
32 | * 2011-09-06: -s reads arguments once. stdin not closed. |
33 | * 2011-09-06: fixed bad argument-freeing loops. |
34 | * 2011-08-27: validates BMP_C() |
35 | * 2011-08-26: validates BMPBIT and BMPSUB |
36 | * 2011-08-25: fixed Init/Xorout reflection logic in -V and -v |
37 | * 2011-01-17: fixed ANSI C warnings |
38 | * 2011-01-15: added NOFORCE |
39 | * 2011-01-14: added -k, -P |
40 | * 2011-01-10: reorganised switches, added -V, -X |
41 | * 2010-12-26: renamed CRC RevEng |
42 | * 2010-12-18: implemented -c, -C |
43 | * 2010-12-14: added and implemented -d, -D, fixed -ipx entry |
44 | * 2010-12-11: implemented -e. first tests |
45 | * 2010-12-10: finalised option processing. started input validation |
46 | * 2010-12-07: started cli |
47 | */ |
48 | |
49 | #include <stdio.h> |
50 | #include <stdlib.h> |
51 | #include "getopt.h" |
52 | #ifdef _WIN32 |
53 | # include <io.h> |
54 | # include <fcntl.h> |
55 | # ifndef STDIN_FILENO |
56 | # define STDIN_FILENO 0 |
57 | # endif /* STDIN_FILENO */ |
58 | #endif /* _WIN32 */ |
59 | |
60 | #include "reveng.h" |
61 | |
62 | static FILE *oread(const char *); |
63 | static poly_t rdpoly(const char *, int, int); |
64 | static void usage(void); |
65 | |
66 | static const char *myname = "reveng"; /* name of our program */ |
67 | |
68 | int reveng_main(int argc, char *argv[]) { |
69 | /* Command-line interface for CRC RevEng. |
70 | * Process options and switches in the argument list and |
71 | * run the required function. |
72 | */ |
73 | |
74 | /* default values */ |
75 | model_t model = { |
76 | PZERO, /* no CRC polynomial, user must specify */ |
77 | PZERO, /* Init = 0 */ |
78 | P_BE, /* RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h */ |
79 | PZERO, /* XorOut = 0 */ |
80 | PZERO, /* check value unused */ |
81 | NULL /* no model name */ |
82 | }; |
83 | int ibperhx = 8, obperhx = 8; |
84 | int rflags = 0, uflags = 0; /* search and UI flags */ |
85 | |
86 | unsigned long width = 0UL; |
87 | int c, mode = 0, args, psets, pass; |
88 | poly_t apoly, crc, qpoly = PZERO, *apolys, *pptr = NULL, *qptr = NULL; |
89 | model_t pset = model, *candmods, *mptr; |
90 | char *string; |
91 | |
92 | myname = argv[0]; |
93 | |
94 | /* stdin must be binary */ |
95 | #ifdef _WIN32 |
96 | _setmode(STDIN_FILENO, _O_BINARY); |
97 | #endif /* _WIN32 */ |
98 | |
99 | SETBMP(); |
100 | |
101 | pos=0; |
102 | optind=1; |
103 | do { |
104 | c=getopt(argc, argv, "?A:BDFLMP:SVXa:bcdefhi:k:lm:p:q:rstuvw:x:yz"); |
105 | switch(c) { |
106 | case 'A': /* A: bits per output character */ |
107 | case 'a': /* a: bits per character */ |
108 | if((obperhx = atoi(optarg)) > BMP_BIT) { |
109 | fprintf(stderr,"%s: argument to -%c must be between 1 and %d\n", myname, c, BMP_BIT); |
110 | return 0; |
111 | //exit(EXIT_FAILURE); |
112 | } |
113 | if(c == 'a') ibperhx = obperhx; |
114 | break; |
115 | case 'b': /* b big-endian (RefIn = false, RefOut = false ) */ |
116 | model.flags &= ~P_REFIN; |
117 | rflags |= R_HAVERI; |
118 | /* fall through: */ |
119 | case 'B': /* B big-endian output (RefOut = false) */ |
120 | model.flags &= ~P_REFOUT; |
121 | rflags |= R_HAVERO; |
122 | mnovel(&model); |
123 | /* fall through: */ |
124 | case 'r': /* r right-justified */ |
125 | model.flags |= P_RTJUST; |
126 | break; |
127 | case 'c': /* c calculate CRC */ |
128 | case 'D': /* D list primary model names */ |
129 | case 'd': /* d dump CRC model */ |
130 | case 'e': /* e echo arguments */ |
131 | case 's': /* s search for algorithm */ |
132 | case 'v': /* v calculate reversed CRC */ |
133 | if(mode) { |
134 | fprintf(stderr,"%s: more than one mode switch specified. Use %s -h for help.\n", myname, myname); |
135 | return 0; |
136 | //exit(EXIT_FAILURE); |
137 | } |
138 | mode = c; |
139 | break; |
140 | case 'F': /* F force search */ |
141 | #ifndef NOFORCE |
142 | uflags |= C_FORCE; |
143 | #endif |
144 | break; |
145 | case 'f': /* f arguments are filenames */ |
146 | uflags |= C_INFILE; |
147 | break; |
148 | case 'h': /* h get help / usage */ |
149 | case 'u': /* u get help / usage */ |
150 | case '?': /* ? get help / usage */ |
151 | default: |
152 | usage(); |
153 | return 0; |
154 | //exit(EXIT_FAILURE); |
155 | break; |
156 | case 'i': /* i: Init value */ |
157 | pptr = &model.init; |
158 | rflags |= R_HAVEI; |
159 | goto ippx; |
160 | case 'k': /* k: polynomial in Koopman notation */ |
161 | pfree(&model.spoly); |
162 | model.spoly = strtop(optarg, 0, 4); |
163 | pkchop(&model.spoly); |
164 | width = plen(model.spoly); |
165 | rflags |= R_HAVEP; |
166 | mnovel(&model); |
167 | break; |
168 | case 'l': /* l little-endian input and output */ |
169 | model.flags |= P_REFIN; |
170 | rflags |= R_HAVERI; |
171 | /* fall through: */ |
172 | case 'L': /* L little-endian output */ |
173 | model.flags |= P_REFOUT; |
174 | rflags |= R_HAVERO; |
175 | mnovel(&model); |
176 | /* fall through: */ |
177 | case 't': /* t left-justified */ |
178 | model.flags &= ~P_RTJUST; |
179 | break; |
180 | case 'm': /* m: select preset CRC model */ |
181 | if(!(c = mbynam(&model, optarg))) { |
182 | fprintf(stderr,"%s: preset model '%s' not found. Use %s -D to list presets.\n", myname, optarg, myname); |
183 | return 0; |
184 | //exit(EXIT_FAILURE); |
185 | } |
60e86577 |
186 | if(c < 0){ |
a71ece51 |
187 | uerror("no preset models available"); |
60e86577 |
188 | return 0; |
189 | } |
a71ece51 |
190 | /* must set width so that parameter to -ipx is not zeroed */ |
191 | width = plen(model.spoly); |
192 | rflags |= R_HAVEP | R_HAVEI | R_HAVERI | R_HAVERO | R_HAVEX; |
193 | break; |
194 | case 'M': /* M non-augmenting algorithm */ |
195 | model.flags &= ~P_MULXN; |
196 | break; |
197 | case 'P': /* P: reversed polynomial */ |
198 | case 'p': /* p: polynomial */ |
199 | pptr = &model.spoly; |
200 | rflags &= ~R_HAVEQ; |
201 | rflags |= R_HAVEP; |
202 | ippx: |
203 | pfree(pptr); |
204 | *pptr = strtop(optarg, 0, 4); |
205 | pright(pptr, width); |
206 | if(c == 'P') |
207 | prev(pptr); |
208 | mnovel(&model); |
209 | break; |
210 | case 'q': /* q: range end polynomial */ |
211 | pptr = &qpoly; |
212 | rflags &= ~R_HAVEP; |
213 | rflags |= R_HAVEQ; |
214 | goto ippx; |
215 | case 'S': /* s space between output characters */ |
216 | model.flags |= P_SPACE; |
217 | break; |
218 | case 'V': /* v reverse algorithm */ |
219 | /* Distinct from the -v switch as the |
220 | * user will have to reverse his or her |
221 | * own arguments. The user cannot dump |
222 | * the model generated by -v either. |
223 | */ |
224 | mrev(&model); |
225 | break; |
226 | case 'w': /* w: CRC width = order - 1 */ |
227 | width = (unsigned long) atol(optarg); |
228 | break; |
229 | case 'X': /* X print uppercase hex */ |
230 | model.flags |= P_UPPER; |
231 | break; |
232 | case 'x': /* x: XorOut value */ |
233 | pptr = &model.xorout; |
234 | rflags |= R_HAVEX; |
235 | goto ippx; |
236 | case 'y': /* y little-endian byte order in files */ |
237 | model.flags |= P_LTLBYT; |
238 | break; |
239 | case 'z': /* z raw binary arguments */ |
240 | model.flags |= P_DIRECT; |
241 | break; |
242 | case -1: /* no more options, continue */ |
243 | ; |
244 | } |
245 | } while(c != -1); |
246 | |
247 | /* canonicalise the model, so the one we dump is the one we |
248 | * calculate with (not with -s, spoly may be blank which will |
249 | * normalise to zero and clear init and xorout.) |
250 | */ |
251 | if(mode != 's') |
252 | mcanon(&model); |
253 | |
254 | switch(mode) { |
255 | case 'v': /* v calculate reversed CRC */ |
256 | /* Distinct from the -V switch as this causes |
257 | * the arguments and output to be reversed as well. |
258 | */ |
259 | /* reciprocate Poly */ |
260 | prcp(&model.spoly); |
261 | |
262 | /* mrev() does: |
263 | * if(refout) prev(init); else prev(xorout); |
264 | * but here the entire argument polynomial is |
265 | * reflected, not just the characters, so RefIn |
266 | * and RefOut are not inverted as with -V. |
267 | * Consequently Init is the mirror image of the |
268 | * one resulting from -V, and so we have: |
269 | */ |
270 | if(~model.flags & P_REFOUT) { |
271 | prev(&model.init); |
272 | prev(&model.xorout); |
273 | } |
274 | |
275 | /* swap init and xorout */ |
276 | apoly = model.init; |
277 | model.init = model.xorout; |
278 | model.xorout = apoly; |
279 | |
280 | /* fall through: */ |
281 | case 'c': /* c calculate CRC */ |
282 | |
283 | /* validate inputs */ |
284 | /* if(plen(model.spoly) == 0) { |
285 | * fprintf(stderr,"%s: no polynomial specified for -%c (add -w WIDTH -p POLY)\n", myname, mode); |
286 | * exit(EXIT_FAILURE); |
287 | * } |
288 | */ |
289 | |
290 | /* in the Williams model, xorout is applied after the refout stage. |
291 | * as refout is part of ptostr(), we reverse xorout here. |
292 | */ |
293 | if(model.flags & P_REFOUT) |
294 | prev(&model.xorout); |
295 | |
296 | for(; optind < argc; ++optind) { |
297 | if(uflags & C_INFILE) |
298 | apoly = rdpoly(argv[optind], model.flags, ibperhx); |
299 | else |
300 | apoly = strtop(argv[optind], model.flags, ibperhx); |
301 | |
302 | if(mode == 'v') |
303 | prev(&apoly); |
304 | |
305 | crc = pcrc(apoly, model.spoly, model.init, model.xorout, model.flags); |
306 | |
307 | if(mode == 'v') |
308 | prev(&crc); |
309 | |
310 | string = ptostr(crc, model.flags, obperhx); |
311 | puts(string); |
312 | free(string); |
313 | pfree(&crc); |
314 | pfree(&apoly); |
315 | } |
316 | break; |
317 | case 'D': /* D dump all models */ |
318 | args = mcount(); |
60e86577 |
319 | if(!args){ |
a71ece51 |
320 | uerror("no preset models available"); |
60e86577 |
321 | return 0; |
322 | } |
a71ece51 |
323 | for(mode = 0; mode < args; ++mode) { |
324 | mbynum(&model, mode); |
325 | mcanon(&model); |
326 | ufound(&model); |
327 | } |
328 | break; |
329 | case 'd': /* d dump CRC model */ |
330 | /* maybe we don't want to do this: |
331 | * either attaching names to arbitrary models or forcing to a preset |
332 | * mmatch(&model, M_OVERWR); |
333 | */ |
60e86577 |
334 | if(~model.flags & P_MULXN){ |
a71ece51 |
335 | uerror("not a Williams model compliant algorithm"); |
60e86577 |
336 | return 0; |
337 | } |
a71ece51 |
338 | string = mtostr(&model); |
339 | puts(string); |
340 | free(string); |
341 | break; |
342 | case 'e': /* e echo arguments */ |
343 | for(; optind < argc; ++optind) { |
344 | if(uflags & C_INFILE) |
345 | apoly = rdpoly(argv[optind], model.flags, ibperhx); |
346 | else |
347 | apoly = strtop(argv[optind], model.flags, ibperhx); |
348 | |
349 | psum(&apoly, model.init, 0UL); |
350 | string = ptostr(apoly, model.flags, obperhx); |
351 | puts(string); |
352 | free(string); |
353 | pfree(&apoly); |
354 | } |
355 | break; |
356 | case 's': /* s search for algorithm */ |
60e86577 |
357 | if(!width){ |
a71ece51 |
358 | uerror("must specify positive -k or -w before -s"); |
60e86577 |
359 | return 0; |
360 | } |
361 | if(~model.flags & P_MULXN){ |
a71ece51 |
362 | uerror("cannot search for non-Williams compliant models"); |
60e86577 |
363 | return 0; |
364 | } |
a71ece51 |
365 | praloc(&model.spoly, width); |
366 | praloc(&model.init, width); |
367 | praloc(&model.xorout, width); |
368 | if(!plen(model.spoly)) |
369 | palloc(&model.spoly, width); |
370 | else |
371 | width = plen(model.spoly); |
372 | |
373 | /* special case if qpoly is zero, search to end of range */ |
374 | if(!ptst(qpoly)) |
375 | rflags &= ~R_HAVEQ; |
376 | |
377 | /* allocate argument array */ |
378 | args = argc - optind; |
60e86577 |
379 | if(!(apolys = malloc(args * sizeof(poly_t)))){ |
a71ece51 |
380 | uerror("cannot allocate memory for argument list"); |
60e86577 |
381 | return 0; |
382 | } |
a71ece51 |
383 | |
384 | for(pptr = apolys; optind < argc; ++optind) { |
385 | if(uflags & C_INFILE) |
386 | *pptr++ = rdpoly(argv[optind], model.flags, ibperhx); |
387 | else |
388 | *pptr++ = strtop(argv[optind], model.flags, ibperhx); |
389 | } |
390 | /* exit value of pptr is used hereafter! */ |
391 | |
392 | /* if endianness not specified, try |
393 | * little-endian then big-endian. |
394 | * NB: crossed-endian algorithms will not be |
395 | * searched. |
396 | */ |
397 | |
398 | /* scan against preset models */ |
399 | if(~uflags & C_FORCE) { |
400 | pass = 0; |
401 | do { |
402 | psets = mcount(); |
403 | while(psets) { |
404 | mbynum(&pset, --psets); |
405 | /* skip if different width, or refin or refout don't match */ |
406 | if(plen(pset.spoly) != width || (model.flags ^ pset.flags) & (P_REFIN | P_REFOUT)) |
407 | continue; |
408 | /* skip if the preset doesn't match specified parameters */ |
409 | if(rflags & R_HAVEP && pcmp(&model.spoly, &pset.spoly)) |
410 | continue; |
411 | if(rflags & R_HAVEI && psncmp(&model.init, &pset.init)) |
412 | continue; |
413 | if(rflags & R_HAVEX && psncmp(&model.xorout, &pset.xorout)) |
414 | continue; |
415 | apoly = pclone(pset.xorout); |
416 | if(pset.flags & P_REFOUT) |
417 | prev(&apoly); |
418 | for(qptr = apolys; qptr < pptr; ++qptr) { |
419 | crc = pcrc(*qptr, pset.spoly, pset.init, apoly, 0); |
420 | if(ptst(crc)) { |
421 | pfree(&crc); |
422 | break; |
423 | } else |
424 | pfree(&crc); |
425 | } |
426 | pfree(&apoly); |
427 | if(qptr == pptr) { |
428 | /* the selected model solved all arguments */ |
429 | mcanon(&pset); |
430 | ufound(&pset); |
431 | uflags |= C_RESULT; |
432 | } |
433 | } |
434 | mfree(&pset); |
435 | |
436 | /* toggle refIn/refOut and reflect arguments */ |
437 | if(~rflags & R_HAVERI) { |
438 | model.flags ^= P_REFIN | P_REFOUT; |
439 | for(qptr = apolys; qptr < pptr; ++qptr) |
440 | prevch(qptr, ibperhx); |
441 | } |
442 | } while(~rflags & R_HAVERI && ++pass < 2); |
443 | } |
444 | if(uflags & C_RESULT) { |
445 | for(qptr = apolys; qptr < pptr; ++qptr) |
446 | pfree(qptr); |
817d7096 |
447 | //return 1; |
a71ece51 |
448 | //exit(EXIT_SUCCESS); |
449 | } |
60e86577 |
450 | if(!(model.flags & P_REFIN) != !(model.flags & P_REFOUT)){ |
a71ece51 |
451 | uerror("cannot search for crossed-endian models"); |
60e86577 |
452 | return 0; |
453 | } |
a71ece51 |
454 | pass = 0; |
455 | do { |
456 | mptr = candmods = reveng(&model, qpoly, rflags, args, apolys); |
457 | if(mptr && plen(mptr->spoly)) |
458 | uflags |= C_RESULT; |
459 | while(mptr && plen(mptr->spoly)) { |
460 | /* results were printed by the callback |
461 | * string = mtostr(mptr); |
462 | * puts(string); |
463 | * free(string); |
464 | */ |
465 | mfree(mptr++); |
466 | } |
467 | free(candmods); |
468 | if(~rflags & R_HAVERI) { |
469 | model.flags ^= P_REFIN | P_REFOUT; |
470 | for(qptr = apolys; qptr < pptr; ++qptr) |
471 | prevch(qptr, ibperhx); |
472 | } |
473 | } while(~rflags & R_HAVERI && ++pass < 2); |
474 | for(qptr = apolys; qptr < pptr; ++qptr) |
475 | pfree(qptr); |
476 | free(apolys); |
477 | if(~uflags & C_RESULT) |
478 | uerror("no models found"); |
479 | break; |
480 | default: /* no mode specified */ |
481 | fprintf(stderr, "%s: no mode switch specified. Use %s -h for help.\n", myname, myname); |
a71ece51 |
482 | //exit(EXIT_FAILURE); |
483 | } |
484 | |
485 | return 1; |
486 | //exit(EXIT_SUCCESS); |
487 | } |
488 | |
489 | void |
490 | ufound(const model_t *model) { |
491 | /* Callback function to report each model found */ |
492 | char *string; |
493 | |
494 | if(!model) return; |
495 | /* generated models will be canonical */ |
496 | string = mtostr(model); |
497 | puts(string); |
498 | free(string); |
499 | } |
500 | |
501 | void |
502 | uerror(const char *msg) { |
503 | /* Callback function to report fatal errors */ |
504 | fprintf(stderr, "%s: %s\n", myname, msg); |
505 | return; |
506 | //exit(EXIT_FAILURE); |
507 | } |
508 | |
509 | void |
510 | uprog(const poly_t gpoly, int flags, unsigned long seq) { |
511 | /* Callback function to report search progress */ |
512 | char *string; |
513 | |
514 | /* Suppress first report in CLI */ |
515 | if(!seq) |
516 | return; |
517 | string = ptostr(gpoly, P_RTJUST, 4); |
518 | fprintf(stderr, "%s: searching: width=%ld poly=0x%s refin=%s refout=%s\n", |
519 | myname, plen(gpoly), string, |
520 | (flags & P_REFIN ? "true" : "false"), |
521 | (flags & P_REFOUT ? "true" : "false") |
522 | ); |
523 | free(string); |
524 | } |
525 | |
526 | static poly_t |
527 | rdpoly(const char *name, int flags, int bperhx) { |
528 | /* read poly from file in chunks and report errors */ |
529 | |
530 | poly_t apoly = PZERO, chunk = PZERO; |
531 | FILE *input; |
532 | |
533 | input = oread(name); |
534 | while(!feof(input) && !ferror(input)) { |
535 | chunk = filtop(input, BUFFER, flags, bperhx); |
536 | psum(&apoly, chunk, plen(apoly)); |
537 | pfree(&chunk); |
538 | } |
539 | if(ferror(input)) { |
540 | fprintf(stderr,"%s: error condition on file '%s'\n", myname, name); |
541 | exit(EXIT_FAILURE); |
542 | } |
543 | /* close file unless stdin */ |
544 | if(input == stdin) |
545 | /* reset EOF condition */ |
546 | clearerr(input); |
547 | else if(fclose(input)) { |
548 | fprintf(stderr,"%s: error closing file '%s'\n", myname, name); |
549 | exit(EXIT_FAILURE); |
550 | } |
551 | return(apoly); |
552 | } |
553 | |
554 | static FILE * |
555 | oread(const char *name) { |
556 | /* open file for reading and report errors */ |
557 | FILE *handle; |
558 | |
559 | /* recognise special name '-' as standard input */ |
560 | if(*name == '-' && name[1] == '\0') |
561 | return(stdin); |
562 | if(!(handle = fopen(name, "rb"))) { |
563 | fprintf(stderr, "%s: cannot open '%s' for reading\n", myname, name); |
564 | return 0; |
565 | //exit(EXIT_FAILURE); |
566 | } |
567 | return(handle); |
568 | } |
569 | |
570 | static void |
571 | usage(void) { |
572 | /* print usage if asked, or if syntax incorrect */ |
573 | fprintf(stderr, |
574 | "CRC RevEng, an arbitrary-precision CRC calculator and algorithm finder\n" |
575 | "Usage:\t"); |
576 | fputs(myname, stderr); |
577 | fprintf(stderr, |
578 | "\t-cdDesvhu? [-bBfFlLMrStVXyz]\n" |
579 | "\t\t[-a BITS] [-A OBITS] [-i INIT] [-k KPOLY] [-m MODEL]\n" |
580 | "\t\t[-p POLY] [-P RPOLY] [-q QPOLY] [-w WIDTH] [-x XOROUT]\n" |
581 | "\t\t[STRING...]\n" |
582 | "Options:\n" |
583 | "\t-a BITS\t\tbits per character (1 to %d)\n" |
584 | "\t-A OBITS\tbits per output character (1 to %d)\n" |
585 | "\t-i INIT\t\tinitial register value\n" |
586 | "\t-k KPOLY\tgenerator in Koopman notation (implies WIDTH)\n" |
587 | "\t-m MODEL\tpreset CRC algorithm\n" |
588 | "\t-p POLY\t\tgenerator or search range start polynomial\n" |
589 | "\t-P RPOLY\treversed generator polynomial\n", |
590 | BMP_BIT, BMP_BIT); |
591 | fprintf(stderr, |
592 | "\t-q QPOLY\tsearch range end polynomial\n" |
593 | "\t-w WIDTH\tregister size, in bits\n" |
594 | "\t-x XOROUT\tfinal register XOR value\n" |
595 | "Modifier switches:\n" |
596 | "\t-b big-endian CRC\t\t-B big-endian CRC output\n" |
597 | "\t-f read files named in STRINGs\t-F find presets less quickly\n" |
598 | "\t-l little-endian CRC\t\t-L little-endian CRC output\n" |
599 | "\t-M non-augmenting algorithm\t-r right-justified output\n" |
600 | "\t-S print spaces between chars\t-t left-justified output\n" |
601 | "\t-V reverse algorithm only\t-X print uppercase hex\n" |
602 | "\t-y low bytes first in files\t-z raw binary STRINGs\n"); |
603 | fprintf(stderr, |
604 | "Mode switches:\n" |
605 | "\t-c calculate CRCs\t\t-d dump algorithm parameters\n" |
606 | "\t-D list preset algorithms\t-e echo (and reformat) input\n" |
607 | "\t-s search for algorithm\t\t-v calculate reversed CRCs\n" |
02984d68 |
608 | "\t-g search for alg given hex+crc\t-h | -u | -? show this help\n" |
609 | "Common Use Examples:\n" |
610 | "\t reveng -g 01020304e3\n" |
611 | "\t Searches for a known/common crc preset that computes the crc\n" |
612 | "\t on the end of the given hex string\n" |
613 | "\t reveng -w 8 -s 01020304e3 010204039d\n" |
614 | "\t Searches for any possible 8 bit width crc calc that computes\n" |
615 | "\t the crc on the end of the given hex string(s)\n" |
616 | "\t reveng -m CRC-8 -c 01020304\n" |
617 | "\t Calculates the crc-8 of the given hex string\n" |
618 | "\t reveng -D\n" |
619 | "\t Outputs a list of all known/common crc models with their\n" |
620 | "\t preset values\n" |
a71ece51 |
621 | "\n" |
622 | "Copyright (C) 2010, 2011, 2012, 2013, 2014, 2015 Gregory Cook\n" |
623 | "This is free software; see the source for copying conditions. There is NO\n" |
624 | "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" |
625 | "Version " |
626 | VERSION |
627 | "\t\t\t\t <http://reveng.sourceforge.net/>\n"); |
628 | } |