cgram.c revision 1.29
1 /* $NetBSD: cgram.c,v 1.29 2022/06/12 14:59:44 rillig Exp $ */ 2 3 /*- 4 * Copyright (c) 2013, 2021 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Roland Illig. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(__RCSID) && !defined(lint) 34 __RCSID("$NetBSD: cgram.c,v 1.29 2022/06/12 14:59:44 rillig Exp $"); 35 #endif 36 37 #include <assert.h> 38 #include <ctype.h> 39 #include <curses.h> 40 #include <err.h> 41 #include <stdbool.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <time.h> 46 47 #include "pathnames.h" 48 49 50 static bool 51 ch_islower(char ch) 52 { 53 return ch >= 'a' && ch <= 'z'; 54 } 55 56 static bool 57 ch_isupper(char ch) 58 { 59 return ch >= 'A' && ch <= 'Z'; 60 } 61 62 static bool 63 ch_isalpha(char ch) 64 { 65 return ch_islower(ch) || ch_isupper(ch); 66 } 67 68 static char 69 ch_toupper(char ch) 70 { 71 return ch_islower(ch) ? (char)(ch - 'a' + 'A') : ch; 72 } 73 74 static char 75 ch_tolower(char ch) 76 { 77 return ch_isupper(ch) ? (char)(ch - 'A' + 'a') : ch; 78 } 79 80 static int 81 imax(int a, int b) 82 { 83 return a > b ? a : b; 84 } 85 86 static int 87 imin(int a, int b) 88 { 89 return a < b ? a : b; 90 } 91 92 //////////////////////////////////////////////////////////// 93 94 struct string { 95 char *s; 96 size_t len; 97 size_t cap; 98 }; 99 100 struct stringarray { 101 struct string *v; 102 size_t num; 103 }; 104 105 static void 106 string_init(struct string *s) 107 { 108 s->s = NULL; 109 s->len = 0; 110 s->cap = 0; 111 } 112 113 static void 114 string_add(struct string *s, char ch) 115 { 116 if (s->len >= s->cap) { 117 s->cap = 2 * s->cap + 16; 118 s->s = realloc(s->s, s->cap); 119 if (s->s == NULL) 120 errx(1, "Out of memory"); 121 } 122 s->s[s->len++] = ch; 123 } 124 125 static void 126 string_finish(struct string *s) 127 { 128 string_add(s, '\0'); 129 s->len--; 130 } 131 132 static void 133 stringarray_init(struct stringarray *a) 134 { 135 a->v = NULL; 136 a->num = 0; 137 } 138 139 static void 140 stringarray_done(struct stringarray *a) 141 { 142 for (size_t i = 0; i < a->num; i++) 143 free(a->v[i].s); 144 free(a->v); 145 } 146 147 static void 148 stringarray_add(struct stringarray *a, struct string *s) 149 { 150 size_t num = a->num++; 151 if (reallocarr(&a->v, a->num, sizeof(a->v[0])) != 0) 152 errx(1, "Out of memory"); 153 a->v[num] = *s; 154 } 155 156 static void 157 stringarray_dup(struct stringarray *dst, const struct stringarray *src) 158 { 159 assert(dst->num == 0); 160 for (size_t i = 0; i < src->num; i++) { 161 struct string str; 162 string_init(&str); 163 for (const char *p = src->v[i].s; *p != '\0'; p++) 164 string_add(&str, *p); 165 string_finish(&str); 166 stringarray_add(dst, &str); 167 } 168 } 169 170 //////////////////////////////////////////////////////////// 171 172 static struct stringarray lines; 173 static struct stringarray sollines; 174 static bool hinting; 175 static int extent_x; 176 static int extent_y; 177 static int offset_x; 178 static int offset_y; 179 static int cursor_x; 180 static int cursor_y; 181 182 static int 183 cur_max_x(void) 184 { 185 return (int)lines.v[cursor_y].len; 186 } 187 188 static int 189 cur_max_y(void) 190 { 191 return extent_y - 1; 192 } 193 194 static char 195 char_left_of_cursor(void) 196 { 197 if (cursor_x > 0) 198 return lines.v[cursor_y].s[cursor_x - 1]; 199 assert(cursor_y > 0); 200 return '\n'; /* eol of previous line */ 201 } 202 203 static char 204 char_at_cursor(void) 205 { 206 if (cursor_x == cur_max_x()) 207 return '\n'; 208 return lines.v[cursor_y].s[cursor_x]; 209 } 210 211 static void 212 getquote(FILE *f) 213 { 214 struct string line; 215 string_init(&line); 216 217 int ch; 218 while ((ch = fgetc(f)) != EOF) { 219 if (ch == '\n') { 220 string_finish(&line); 221 stringarray_add(&lines, &line); 222 string_init(&line); 223 } else if (ch == '\t') { 224 string_add(&line, ' '); 225 while (line.len % 8 != 0) 226 string_add(&line, ' '); 227 } else if (ch == '\b') { 228 if (line.len > 0) 229 line.len--; 230 } else { 231 string_add(&line, (char)ch); 232 } 233 } 234 235 stringarray_dup(&sollines, &lines); 236 237 extent_y = (int)lines.num; 238 for (int i = 0; i < extent_y; i++) 239 extent_x = imax(extent_x, (int)lines.v[i].len); 240 } 241 242 static void 243 readfile(const char *name) 244 { 245 FILE *f = fopen(name, "r"); 246 if (f == NULL) 247 err(1, "%s", name); 248 249 getquote(f); 250 251 if (fclose(f) != 0) 252 err(1, "%s", name); 253 } 254 255 256 static void 257 readquote(void) 258 { 259 FILE *f = popen(_PATH_FORTUNE, "r"); 260 if (f == NULL) 261 err(1, "%s", _PATH_FORTUNE); 262 263 getquote(f); 264 265 if (pclose(f) != 0) 266 exit(1); /* error message must come from child process */ 267 } 268 269 static void 270 encode(void) 271 { 272 int key[26]; 273 274 for (int i = 0; i < 26; i++) 275 key[i] = i; 276 277 for (int i = 26; i > 1; i--) { 278 int c = (int)(random() % i); 279 int t = key[i - 1]; 280 key[i - 1] = key[c]; 281 key[c] = t; 282 } 283 284 for (int y = 0; y < extent_y; y++) { 285 for (char *p = lines.v[y].s; *p != '\0'; p++) { 286 if (ch_islower(*p)) 287 *p = (char)('a' + key[*p - 'a']); 288 if (ch_isupper(*p)) 289 *p = (char)('A' + key[*p - 'A']); 290 } 291 } 292 } 293 294 static void 295 substitute(char a, char b) 296 { 297 char la = ch_tolower(a); 298 char ua = ch_toupper(a); 299 char lb = ch_tolower(b); 300 char ub = ch_toupper(b); 301 302 for (int y = 0; y < (int)lines.num; y++) { 303 for (char *p = lines.v[y].s; *p != '\0'; p++) { 304 if (*p == la) 305 *p = lb; 306 else if (*p == ua) 307 *p = ub; 308 else if (*p == lb) 309 *p = la; 310 else if (*p == ub) 311 *p = ua; 312 } 313 } 314 } 315 316 static bool 317 is_solved(void) 318 { 319 for (size_t i = 0; i < lines.num; i++) 320 if (strcmp(lines.v[i].s, sollines.v[i].s) != 0) 321 return false; 322 return true; 323 } 324 325 //////////////////////////////////////////////////////////// 326 327 static void 328 redraw(void) 329 { 330 erase(); 331 332 int max_y = imin(LINES - 1, extent_y - offset_y); 333 for (int y = 0; y < max_y; y++) { 334 move(y, 0); 335 336 int len = (int)lines.v[offset_y + y].len; 337 int max_x = imin(COLS - 1, len - offset_x); 338 const char *line = lines.v[offset_y + y].s; 339 const char *solline = sollines.v[offset_y + y].s; 340 341 for (int x = 0; x < max_x; x++) { 342 char ch = line[offset_x + x]; 343 bool bold = hinting && 344 (ch == solline[offset_x + x] || !ch_isalpha(ch)); 345 346 if (bold) 347 attron(A_BOLD); 348 addch(ch); 349 if (bold) 350 attroff(A_BOLD); 351 } 352 clrtoeol(); 353 } 354 355 move(LINES - 1, 0); 356 addstr("~ to quit, * to cheat, ^pnfb to move"); 357 358 if (is_solved()) { 359 if (extent_y + 1 - offset_y < LINES - 2) 360 move(extent_y + 1 - offset_y, 0); 361 else 362 addch(' '); 363 attron(A_BOLD | A_STANDOUT); 364 addstr("*solved*"); 365 attroff(A_BOLD | A_STANDOUT); 366 } 367 368 move(cursor_y - offset_y, cursor_x - offset_x); 369 370 refresh(); 371 } 372 373 //////////////////////////////////////////////////////////// 374 375 static void 376 saturate_cursor(void) 377 { 378 cursor_y = imax(cursor_y, 0); 379 cursor_y = imin(cursor_y, cur_max_y()); 380 381 assert(cursor_x >= 0); 382 cursor_x = imin(cursor_x, cur_max_x()); 383 } 384 385 static void 386 scroll_into_view(void) 387 { 388 if (cursor_x < offset_x) 389 offset_x = cursor_x; 390 if (cursor_x > offset_x + COLS - 1) 391 offset_x = cursor_x - (COLS - 1); 392 393 if (cursor_y < offset_y) 394 offset_y = cursor_y; 395 if (cursor_y > offset_y + LINES - 2) 396 offset_y = cursor_y - (LINES - 2); 397 } 398 399 static bool 400 can_go_left(void) 401 { 402 return cursor_y > 0 || 403 (cursor_y == 0 && cursor_x > 0); 404 } 405 406 static bool 407 can_go_right(void) 408 { 409 return cursor_y < cur_max_y() || 410 (cursor_y == cur_max_y() && cursor_x < cur_max_x()); 411 } 412 413 static void 414 go_to_prev_line(void) 415 { 416 cursor_y--; 417 cursor_x = cur_max_x(); 418 } 419 420 static void 421 go_to_next_line(void) 422 { 423 cursor_x = 0; 424 cursor_y++; 425 } 426 427 static void 428 go_left(void) 429 { 430 if (cursor_x > 0) 431 cursor_x--; 432 else if (cursor_y > 0) 433 go_to_prev_line(); 434 } 435 436 static void 437 go_right(void) 438 { 439 if (cursor_x < cur_max_x()) 440 cursor_x++; 441 else if (cursor_y < cur_max_y()) 442 go_to_next_line(); 443 } 444 445 static void 446 go_to_prev_word(void) 447 { 448 while (can_go_left() && !ch_isalpha(char_left_of_cursor())) 449 go_left(); 450 451 while (can_go_left() && ch_isalpha(char_left_of_cursor())) 452 go_left(); 453 } 454 455 static void 456 go_to_next_word(void) 457 { 458 while (can_go_right() && ch_isalpha(char_at_cursor())) 459 go_right(); 460 461 while (can_go_right() && !ch_isalpha(char_at_cursor())) 462 go_right(); 463 } 464 465 static bool 466 can_substitute_here(int ch) 467 { 468 return isascii(ch) && 469 ch_isalpha((char)ch) && 470 cursor_x < cur_max_x() && 471 ch_isalpha(char_at_cursor()); 472 } 473 474 static void 475 handle_char_input(int ch) 476 { 477 if (ch == char_at_cursor()) 478 go_right(); 479 else if (can_substitute_here(ch)) { 480 substitute(char_at_cursor(), (char)ch); 481 go_right(); 482 } else 483 beep(); 484 } 485 486 static bool 487 handle_key(void) 488 { 489 int ch = getch(); 490 491 switch (ch) { 492 case 1: /* ^A */ 493 case KEY_BEG: 494 case KEY_HOME: 495 cursor_x = 0; 496 break; 497 case 2: /* ^B */ 498 case KEY_LEFT: 499 go_left(); 500 break; 501 case 5: /* ^E */ 502 case KEY_END: 503 cursor_x = cur_max_x(); 504 break; 505 case 6: /* ^F */ 506 case KEY_RIGHT: 507 go_right(); 508 break; 509 case '\t': 510 go_to_next_word(); 511 break; 512 case KEY_BTAB: 513 go_to_prev_word(); 514 break; 515 case '\n': 516 go_to_next_line(); 517 break; 518 case 12: /* ^L */ 519 clear(); 520 break; 521 case 14: /* ^N */ 522 case KEY_DOWN: 523 cursor_y++; 524 break; 525 case 16: /* ^P */ 526 case KEY_UP: 527 cursor_y--; 528 break; 529 case KEY_PPAGE: 530 cursor_y -= LINES - 2; 531 break; 532 case KEY_NPAGE: 533 cursor_y += LINES - 2; 534 break; 535 case '*': 536 hinting = !hinting; 537 break; 538 case '~': 539 return false; 540 case KEY_RESIZE: 541 break; 542 default: 543 handle_char_input(ch); 544 break; 545 } 546 return true; 547 } 548 549 static void 550 init(const char *filename) 551 { 552 stringarray_init(&lines); 553 stringarray_init(&sollines); 554 srandom((unsigned int)time(NULL)); 555 if (filename != NULL) { 556 readfile(filename); 557 } else { 558 readquote(); 559 } 560 encode(); 561 562 initscr(); 563 cbreak(); 564 noecho(); 565 keypad(stdscr, true); 566 } 567 568 static void 569 loop(void) 570 { 571 for (;;) { 572 redraw(); 573 if (!handle_key()) 574 break; 575 saturate_cursor(); 576 scroll_into_view(); 577 } 578 } 579 580 static void 581 done(void) 582 { 583 move(LINES - 1, 0); 584 clrtoeol(); 585 refresh(); 586 587 endwin(); 588 589 stringarray_done(&sollines); 590 stringarray_done(&lines); 591 } 592 593 594 static void __dead 595 usage(void) 596 { 597 598 fprintf(stderr, "usage: %s [file]\n", getprogname()); 599 exit(1); 600 } 601 602 int 603 main(int argc, char *argv[]) 604 { 605 606 setprogname(argv[0]); 607 if (argc != 1 && argc != 2) 608 usage(); 609 610 init(argc > 1 ? argv[1] : NULL); 611 loop(); 612 done(); 613 return 0; 614 } 615
Indexes created Tue Sep 30 17:09:57 GMT 2025