viiper.c

   1 /*******************************************************************************
   2  viiper 0.1
   3  By Tobias Girstmair, 2018
   4
   5  ./viiper 40x25
   6  (see ./viiper -h for full list of options)
   7
   8  KEYBINDINGS:  - hjkl to move
   9                - p to pause and resume
  10                - r to restart
  11                - q to quit
  12                - (see `./minesviiper -h' for all keybindings)
  13
  14  GNU GPL v3, see LICENSE or https://www.gnu.org/licenses/gpl-3.0.txt
  15 *******************************************************************************/
  16
  17
  18 #define _POSIX_C_SOURCE 2 /*for getopt and sigaction in c99, sigsetjmp*/
  19 #include <setjmp.h>
  20 #include <signal.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/ioctl.h>
  25 #include <sys/time.h>
  26 #include <termios.h>
  27 #include <time.h>
  28 #include <unistd.h>
  29
  30 #include "viiper.h"
  31 #include "schemes.h"
  32
  33 #define MIN(a,b) (a>b?b:a)
  34 #define MAX(a,b) (a>b?a:b)
  35 #define CLAMP(a,m,M) (a<m?m:(a>M?M:a))
  36 #define printm(n, s) for (int _loop = 0; _loop < n; _loop++) fputs (s, stdout)
  37 #define print(str) fputs (str?str:"", stdout)
  38 #define CTRL_ 0x1F &
  39
  40 #define OPPOSITE(dir) ( \
  41         dir == EAST  ? WEST  :   \
  42         dir == WEST  ? EAST  :   \
  43         dir == NORTH ? SOUTH :   \
  44         dir == SOUTH ? NORTH : -1)
  45
  46 #define COL_OFFSET 1
  47 #define LINE_OFFSET 1
  48 #define LINES_AFTER 1
  49 #define CW op.sch->cell_width
  50
  51 #define SPEEDUP_AFTER 100 /* increment speed every n points */
  52 #define BONUS_INTERVAL 90 /* how often a bonus item is spawned */
  53 #define BONUS_DURATION 15 /* how long one can catch the bonus */
  54 #define BONUS_WARN      5 /* how long before the removal to warn */
  55
  56 struct game {
  57         int w; /* field width */
  58         int h; /* field height */
  59         int d; /* direction the snake is looking */
  60         int p; /* score */
  61         float v; /* velocity in moves per second */
  62         time_t t; /* time of game start */
  63         time_t b; /* time of next bonus item spawn */
  64         struct snake* s; /* snek */
  65         struct item* i; /* items (food, boni) */
  66         struct directions {
  67                 int h; /* write head */
  68                 int n; /* number of elements */
  69                 int c[16];
  70         } k; /* ring buffer for direction events */
  71 } g;
  72
  73 struct opt {
  74         int l; /* initial snake length */
  75         int s; /* initial snake speed */
  76         struct scheme* sch;
  77 } op;
  78
  79 jmp_buf game_over;
  80
  81 int main (int argc, char** argv) {
  82         /* defaults: */
  83         g.w = 30;
  84         g.h = 20;
  85         op.l = 10;
  86         op.s = 8;
  87         op.sch = &unic0de;
  88
  89         int optget;
  90         opterr = 0; /* don't print message on unrecognized option */
  91         while ((optget = getopt (argc, argv, "+s:l:dh")) != -1) {
  92                 switch (optget) {
  93                 case 's':
  94                         op.s = atof(optarg);
  95                         if (op.s < 1) {
  96                                 fprintf (stderr, "speed must be >= 1\n");
  97                                 return 1;
  98                         }
  99                         break;
 100                 case 'l':
 101                         op.l = atoi(optarg);
 102                         if (op.s < 2 || op.s > g.w*g.h-1) {
 103                                 fprintf (stderr, "length must be >= 2 and < W*H\n");
 104                                 return 1;
 105                         }
 106                         break;
 107                 case 'd': op.sch = &vt220_charset; break;
 108                 case 'h':
 109                 default:
 110                         fprintf (stderr, SHORTHELP LONGHELP, argv[0]);
 111                         return !(optget=='h');
 112                 }
 113         } if (optind < argc) { /* parse Fieldspec */
 114                 int n = sscanf (argv[optind], "%dx%d", &g.w, &g.h);
 115
 116                 if (n < 2) {
 117                         fprintf(stderr,"FIELDSIZE is WxH (width 'x' height)\n");
 118                         return 1;
 119                 }
 120         }
 121
 122         clamp_fieldsize();
 123
 124         srand(time(0));
 125         signal_setup();
 126         screen_setup(1);
 127         atexit (*quit);
 128
 129         char* end_screen_msg = "";
 130 restart:
 131         switch (sigsetjmp(game_over, 1)) {
 132         case GAME_INIT:
 133         case GAME_START:
 134                 viiper();
 135                 break; /* function doesn't return, but `-Wextra' complains */
 136         case GAME_OVER:
 137                 end_screen_msg = " GAME  OVER ";
 138                 goto end_screen;
 139         case GAME_WON:
 140                 end_screen_msg = "CONGRATULATIONS!";
 141                 goto end_screen;
 142 end_screen:
 143                 timer_setup(0);
 144                 show_playfield();
 145                 for (;;) switch (end_screen(end_screen_msg)) {
 146                 case 'r': goto restart;
 147                 case 'q': goto quit;
 148                 case CTRL_'L':
 149                         screen_setup(1);
 150                         show_playfield();
 151                         break;
 152                 default: continue;
 153                 }
 154         case GAME_EXIT:
 155                 goto quit;
 156         }
 157
 158 quit:
 159         return 0;
 160 }
 161
 162 int viiper(void) {
 163         init_snake();
 164         show_playfield ();
 165         g.d = EAST;
 166         g.v = op.s;
 167
 168         timer_setup(1);
 169         g.t = time(NULL);
 170         g.p = 0;
 171         g.k.n = 0;
 172         g.b = time(NULL) + BONUS_INTERVAL;
 173
 174         spawn_item(FOOD, rand() % NUM_FOODS, NULL); //TODO: shape distribution, so bigger values get selected less
 175
 176         for(;;) {
 177                 switch (getctrlseq()) {
 178                 case 'h': case CTRSEQ_CURSOR_LEFT: append_movement(WEST); break;
 179                 case 'j': case CTRSEQ_CURSOR_DOWN: append_movement(SOUTH);break;
 180                 case 'k': case CTRSEQ_CURSOR_UP:   append_movement(NORTH);break;
 181                 case 'l': case CTRSEQ_CURSOR_RIGHT:append_movement(EAST); break;
 182                 case 'p': pause_game(); break;
 183                 case 'r': siglongjmp(game_over, GAME_START);
 184                 case 'q': siglongjmp(game_over, GAME_EXIT);
 185                 case CTRL_'L':
 186                         screen_setup(1);
 187                         show_playfield();
 188                         break;
 189                 case 0x02: /* STX; gets sent when returning from SIGALRM */
 190                         continue;
 191                 }
 192         }
 193
 194 }
 195
 196 #define pop_dir() (g.k.n? g.k.c[(16+g.k.h-g.k.n--)%16] : NONE)
 197 void snake_advance (void) {
 198         int respawn = 0;
 199         struct item* i; /*temporary item (defined here to respawn at the end) */
 200         int new_dir = pop_dir();
 201         /* switch direction if new one is in the buffer and it won't kill us: */
 202         if (new_dir && g.d != OPPOSITE(new_dir)) g.d = new_dir;
 203
 204         int new_row = g.s->r +(g.d==SOUTH) -(g.d==NORTH);
 205         int new_col = g.s->c +(g.d==EAST)  -(g.d==WEST);
 206
 207         /* detect food hit and spawn a new food */
 208         for (i = g.i; i; i = i->next) {
 209                 if (i->r == new_row && i->c == new_col) {
 210                         consume_item (i);
 211
 212                         switch (i->t) {
 213                         case FOOD: respawn = 1; break;
 214                         case BONUS: remove_bonus(i); break;
 215                         }
 216                         break;
 217                 }
 218         }
 219
 220         if (new_row >= g.h || new_col >= g.w || new_row < 0 || new_col < 0)
 221                 siglongjmp(game_over, GAME_OVER);
 222
 223         struct snake* new_head;
 224         struct snake* new_tail; /* former second-to-last element */
 225         for (new_tail = g.s; new_tail->next->next; new_tail = new_tail->next)
 226                 /*use the opportunity of looping to check if we eat ourselves:*/
 227                 if(new_tail->next->r == new_row && new_tail->next->c == new_col)
 228                         siglongjmp(game_over, GAME_OVER);
 229         int old_tail[2] = {new_tail->next->r, new_tail->next->c};/*gets erased*/
 230         new_head = new_tail->next; /* reuse element instead of malloc() */
 231         new_tail->next = NULL;
 232
 233         new_head->r = new_row;
 234         new_head->c = new_col;
 235         new_head->next = g.s;
 236
 237         g.s = new_head;
 238
 239         if (respawn) spawn_item(FOOD, rand() % NUM_FOODS, i);
 240         draw_sprites (old_tail[0], old_tail[1]);
 241 }
 242
 243 void spawn_item (int type, int value, struct item* p_item) {
 244         int row, col;
 245         char occupied[g.w][g.h]; int snake_len = 0;
 246         memset(*occupied, 0, g.w*g.h);
 247 try_again:
 248         row = rand() % g.h;
 249         col = rand() % g.w;
 250         if (snake_len >= g.w*g.h-1) siglongjmp(game_over, GAME_WON);
 251         /* loop through snake to check if we aren't on it */
 252         if (occupied[row][col]) goto try_again; /* shortcut */
 253         for (struct snake* s = g.s; s; s = s->next)
 254                 if (s->r == row && s->c == col) {
 255                         occupied[s->r][s->c] = 1; snake_len++;
 256                         goto try_again;
 257                 }
 258
 259         /* if we got a item buffer reuse it, otherwise create a new one: */
 260         struct item* new_item;
 261         if (p_item) new_item = p_item;
 262         else new_item = malloc (sizeof(struct item));
 263
 264         new_item->r = row;
 265         new_item->c = col;
 266         new_item->t = type;
 267         new_item->v = value;
 268         new_item->s = time(0);
 269         if (g.i) g.i->prev = new_item;
 270         new_item->next = g.i;
 271         new_item->prev = NULL;
 272
 273         g.i = new_item;
 274 }
 275
 276 void consume_item (struct item* i) {
 277         int old_score = g.p;
 278
 279         switch (i->t) {
 280         case FOOD:
 281                 switch (i->v) {
 282                 case FOOD_5:  g.p +=  5; break;
 283                 case FOOD_10: g.p += 10; break;
 284                 case FOOD_20: g.p += 20; break;
 285                 }
 286                 snake_append(&g.s, -1, -1);
 287                 break;       /* will be reused as the head before it is drawn */
 288         case BONUS:
 289                 switch (i->v) {
 290                 case BONUS_SNIP:
 291                         for (int i = 5; i && g.s->next->next; i--) {
 292                                 struct snake* p = g.s;
 293                                 while (p->next->next) p = p->next;
 294                                 free (p->next);
 295                                 p->next = NULL;
 296                         }
 297                         show_playfield();
 298                         break;
 299                 case BONUS_GROW:
 300                         for (int i = 5; i; i--) snake_append(&g.s, -1, -1);
 301                         break;
 302                 case BONUS_SLOW:
 303                         if (g.v > 1) g.v--;
 304                         timer_setup(1);
 305                         break;
 306                 case BONUS_FAST:
 307                         g.v++;
 308                         timer_setup(1);
 309                         break;
 310                 }
 311                 break;
 312         }
 313
 314         if (i->next) i->next->prev = i->prev;
 315         if (i->prev) i->prev->next = i->next;
 316         else g.i = i->next;
 317
 318         /* snake speedup every 100 points: */
 319         if (g.p/SPEEDUP_AFTER - old_score/SPEEDUP_AFTER) g.v++, timer_setup(1);
 320 }
 321
 322 void spawn_bonus(void) {
 323         for (struct item* i = g.i; i; i = i->next)
 324                 if (i->t == BONUS) { /* bonus already there */
 325                         if (((i->s+BONUS_DURATION)-time(NULL)) < 0) {
 326                                 remove_bonus(i); /* remove if over lifetime */
 327                         }
 328                         return;
 329                 }
 330         if (g.b < time(NULL)) { /* time to spawn item: */
 331                 spawn_item(BONUS, rand() % NUM_BONI, NULL);
 332                 g.b = time(NULL) + BONUS_INTERVAL; //TODO: only start counting after old bonus was removed/eaten
 333         }
 334 }
 335
 336 void show_playfield (void) {
 337         move_ph (0,0);
 338
 339         /* top border */
 340         print(BORDER(T,L));
 341         printm (g.w, BORDER(T,C));
 342         printf ("%s\n", BORDER(T,R));
 343
 344         /* main area */
 345         for (int row = 0; row < g.h; row++)
 346                 printf ("%s%*s%s\n", BORDER(C,L), CW*g.w, "", BORDER(C,R));
 347
 348         /* bottom border */
 349         print(BORDER(B,L));
 350         printm (g.w, BORDER(B,C));
 351         print (BORDER(B,R));
 352
 353         draw_sprites (-1,-1);
 354 }
 355
 356 void draw_sprites (int erase_r, int erase_c) {
 357         /* erase old tail, if any */
 358         if (erase_r >= 0 && erase_c >= 0) {
 359                 move_ph (erase_r+LINE_OFFSET, erase_c*CW+COL_OFFSET);
 360                 printm (CW, " ");
 361         }
 362
 363         /* print snake */
 364         struct snake* last = NULL;
 365         int color = 2;
 366         for (struct snake* s = g.s; s; s = s->next) {
 367                 if (s->r < 0 || s->c < 0) continue; /*can't draw outside term.*/
 368                 move_ph (s->r+LINE_OFFSET, s->c*CW+COL_OFFSET);
 369
 370                 int predecessor = (last==NULL)?NONE:
 371                         (last->r < s->r) ? NORTH:
 372                         (last->r > s->r) ? SOUTH:
 373                         (last->c > s->c) ? EAST:
 374                         (last->c < s->c) ? WEST:NONE;
 375                 int successor = (s->next == NULL)?NONE:
 376                         (s->next->r < s->r) ? NORTH:
 377                         (s->next->r > s->r) ? SOUTH:
 378                         (s->next->c > s->c) ? EAST:
 379                         (s->next->c < s->c) ? WEST:NONE;
 380
 381                 printf ("\033[%sm", op.sch->color[color]);
 382                 print (op.sch->snake[predecessor][successor]);
 383                 printf ("\033[0m");
 384                 last = s;
 385                 color = !color;
 386         }
 387
 388         /* print item queue */
 389         for (struct item* i = g.i; i; i = i->next) {
 390                 move_ph (i->r+LINE_OFFSET, i->c*CW+COL_OFFSET);
 391                 if      (i->t == FOOD)  print(op.sch->food[i->v]);
 392                 else if (i->t == BONUS) {
 393                         if (i->s + BONUS_DURATION-BONUS_WARN < time(NULL))
 394                                 printf("\033[5m%s\033[25m", op.sch->boni[i->v]);
 395                         else print(op.sch->boni[i->v]);
 396                 }
 397         }
 398
 399         /* print score */
 400         int score_width = g.p > 9999?6:4;
 401         move_ph (0, (g.w*CW-score_width)/2-COL_OFFSET);
 402         printf ("%s %0*d %s", BORDER(S,L), score_width, g.p, BORDER(S,R));
 403 }
 404
 405 void pause_game (void) {
 406         time_t pause_start = time(NULL);
 407         time_t pause_diff;
 408         timer_setup(0);
 409
 410         move_ph (g.h/2+LINE_OFFSET, g.w*CW/2);
 411         printf ("\033[5;7m PAUSE \033[0m"); /* blinking reverse text */
 412         if (getchar() == 'q')
 413                 siglongjmp(game_over, GAME_EXIT);
 414
 415         /* update all timers, so bonus items don't get out of sync: */
 416         pause_diff = time(NULL) - pause_start;
 417         g.b += pause_diff;
 418         for (struct item* i = g.i; i; i = i->next)
 419                 i->s += pause_diff;
 420
 421         show_playfield();
 422         timer_setup(1);
 423 }
 424
 425 #define MOVE_POPUP(WIDTH, LINE) \
 426         move_ph(g.h/2+LINE_OFFSET-1+LINE,(g.w*op.sch->display_width-WIDTH)/2)
 427         //TODO: macro does not correctly centre in DEC mode
 428 int end_screen(char* message) {
 429         int msg_w = strlen(message);
 430         MOVE_POPUP(msg_w, -1);
 431         print(BORDER(T,L));
 432         printm ((msg_w+2)/op.sch->display_width, BORDER(T,C));
 433         print (BORDER(T,R));
 434
 435         MOVE_POPUP(msg_w, 0);
 436         printf("%s %s %s", BORDER(C,L), message, BORDER(C,R));
 437         MOVE_POPUP(msg_w, 1);
 438         //TODO: requires shifting into ASCII/multilingual charset in DEC mode -- put graphics into upper/right charset?
 439         printf("%s `r' restart%*s%s", BORDER(C,L), msg_w-10, "", BORDER(C,R));
 440         MOVE_POPUP(msg_w, 2);
 441         printf("%s `q' quit%*s%s", BORDER(C,L), msg_w-7, "", BORDER(C,R));
 442
 443         MOVE_POPUP(msg_w, 3);
 444         print(BORDER(B,L));
 445         printm ((msg_w+2)/op.sch->display_width, BORDER(B,C));
 446         print (BORDER(B,R));
 447         fflush(stdout);
 448
 449         return getctrlseq();
 450 }
 451
 452 void snake_append (struct snake** s, int row, int col) {
 453         struct snake* new = malloc (sizeof(struct snake));
 454         new->r = row;
 455         new->c = col;
 456         new->next = NULL;
 457
 458         if (*s) {
 459                 struct snake* p = *s;
 460                 while (p->next) p = p->next;
 461                 p->next = new;
 462         } else {
 463                 *s = new;
 464         }
 465 }
 466
 467 void remove_bonus (struct item*  i) {
 468         if (i->next) i->next->prev = i->prev;
 469         if (i->prev) i->prev->next = i->next;
 470         else g.i = i->next;
 471
 472         draw_sprites (i->r, i->c); /* overwrite sprite */
 473
 474         free(i);
 475 }
 476
 477 #define free_ll(head) do{ \
 478         while (head) { \
 479                 void* tmp = head; \
 480                 head = head->next; \
 481                 free(tmp); \
 482         } \
 483         head = NULL; \
 484 }while(0)
 485
 486 void init_snake() {
 487         free_ll(g.s);
 488         free_ll(g.i);
 489
 490         int direction = WEST;
 491         int r = g.h/2;
 492         int c = g.w/2;
 493         int min_r = 0;
 494         int max_r = g.h-1;
 495         int min_c = 0;
 496         int max_c = g.w-1;
 497         for (int i = 0; i < op.l; i++) {
 498                 switch (direction) {
 499                 case NORTH: r--; if(r <= min_r){direction=EAST; min_r++;}break;
 500                 case EAST:  c++; if(c >= max_c){direction=SOUTH;max_c--;}break;
 501                 case SOUTH: r++; if(r >= max_r){direction=WEST; max_r--;}break;
 502                 case WEST:  c--; if(c <= min_c){direction=NORTH;min_c++;}break;
 503                 }
 504
 505                 snake_append(&g.s, r, c);
 506         }
 507 }
 508
 509 void quit (void) {
 510         screen_setup(0);
 511         free_ll(g.s);
 512         free_ll(g.i);
 513 }
 514
 515 enum esc_states {
 516         START,
 517         ESC_SENT,
 518         CSI_SENT,
 519         MOUSE_EVENT,
 520 };
 521 int getctrlseq (void) {
 522         int c;
 523         int state = START;
 524         while ((c = getchar()) != EOF) {
 525                 switch (state) {
 526                 case START:
 527                         switch (c) {
 528                         case '\033': state=ESC_SENT; break;
 529                         default: return c;
 530                         }
 531                         break;
 532                 case ESC_SENT:
 533                         switch (c) {
 534                         case '[': state=CSI_SENT; break;
 535                         default: return CTRSEQ_INVALID;
 536                         }
 537                         break;
 538                 case CSI_SENT:
 539                         switch (c) {
 540                         case 'A': return CTRSEQ_CURSOR_UP;
 541                         case 'B': return CTRSEQ_CURSOR_DOWN;
 542                         case 'C': return CTRSEQ_CURSOR_RIGHT;
 543                         case 'D': return CTRSEQ_CURSOR_LEFT;
 544                         default: return CTRSEQ_INVALID;
 545                         }
 546                         break;
 547                 default:
 548                         return CTRSEQ_INVALID;
 549                 }
 550         }
 551         return 2;
 552 }
 553
 554 void append_movement (int dir) {
 555         if (g.k.n > 15) return; /* no space in buffer */
 556         if (g.k.n && g.k.c[(16+g.k.h-1)%16] == dir)
 557                 return; /* don't add the same direction twice */
 558
 559         g.k.c[g.k.h] = dir;
 560         g.k.n++;
 561         g.k.h = (g.k.h+1) % 16;
 562 }
 563
 564 void move_ph (int line, int col) {
 565         /* move printhead to zero-indexed position */
 566         printf ("\033[%d;%dH", line+1, col+1);
 567 }
 568
 569 void clamp_fieldsize (void) {
 570         /* clamp field size to terminal size and mouse maximum: */
 571         struct winsize w;
 572         ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
 573
 574         if (g.w < 10) g.w = 10;
 575         if (g.h < 10) g.h = 10;
 576
 577         if (COL_OFFSET + g.w*CW + COL_OFFSET > w.ws_col)
 578                 g.w = (w.ws_col - 2*COL_OFFSET) / op.sch->display_width;
 579         if (LINE_OFFSET + g.h + LINES_AFTER > w.ws_row)
 580                 g.h = w.ws_row - (LINE_OFFSET+LINES_AFTER);
 581 }
 582
 583 void timer_setup (int enable) {
 584         static struct itimerval tbuf;
 585         tbuf.it_interval.tv_sec  = 0;
 586         tbuf.it_interval.tv_usec = (1000000/g.v)-1; /*WARN: 1 <= g.v <= 999999*/
 587
 588         if (enable) {
 589                 tbuf.it_value.tv_sec  = tbuf.it_interval.tv_sec;
 590                 tbuf.it_value.tv_usec = tbuf.it_interval.tv_usec;
 591         } else {
 592                 tbuf.it_value.tv_sec  = 0;
 593                 tbuf.it_value.tv_usec = 0;
 594         }
 595
 596         if ( setitimer(ITIMER_REAL, &tbuf, NULL) == -1 ) {
 597                 perror("setitimer");
 598                 exit(1);
 599         }
 600
 601 }
 602
 603 void signal_setup (void) {
 604         struct sigaction saction;
 605
 606         saction.sa_handler = signal_handler;
 607         sigemptyset(&saction.sa_mask);
 608         saction.sa_flags = 0;
 609         if (sigaction(SIGALRM, &saction, NULL) < 0 ) {
 610                 perror("SIGALRM");
 611                 exit(1);
 612         }
 613
 614         if (sigaction(SIGINT, &saction, NULL) < 0 ) {
 615                 perror ("SIGINT");
 616                 exit (1);
 617         }
 618
 619         if (sigaction(SIGCONT, &saction, NULL) < 0 ) {
 620                 perror ("SIGCONT");
 621                 exit (1);
 622         }
 623 }
 624
 625 void signal_handler (int signum) {
 626         switch (signum) {
 627         case SIGALRM:
 628                 snake_advance();
 629                 spawn_bonus(); //TODO: currently, a bonus is spawned every x secs. should be x secs after last bonus disappeared.
 630                 break;
 631         case SIGINT:
 632                 exit(128+SIGINT);
 633         case SIGCONT:
 634                 screen_setup(1);
 635                 show_playfield();
 636         }
 637 }
 638
 639 void screen_setup (int enable) {
 640         if (enable) {
 641                 raw_mode(1);
 642                 printf ("\033[s\033[?47h"); /* save cursor, alternate screen */
 643                 printf ("\033[H\033[J"); /* reset cursor, clear screen */
 644                 printf ("\033[?25l"); /* hide cursor */
 645                 print (op.sch->init_seq); /* swich charset, if necessary */
 646         } else {
 647                 print (op.sch->reset_seq); /* reset charset, if necessary */
 648                 printf ("\033[?25h"); /* show cursor */
 649                 printf ("\033[?47l\033[u"); /* primary screen, restore cursor */
 650                 raw_mode(0);
 651         }
 652 }
 653
 654 /* http://users.csc.calpoly.edu/~phatalsk/357/lectures/code/sigalrm.c */
 655 void raw_mode(int enable) {
 656         static struct termios saved_term_mode;
 657         struct termios raw_term_mode;
 658
 659         if (enable) {
 660                 tcgetattr(STDIN_FILENO, &saved_term_mode);
 661                 raw_term_mode = saved_term_mode;
 662                 raw_term_mode.c_lflag &= ~(ICANON | ECHO);
 663                 raw_term_mode.c_cc[VMIN] = 1 ;
 664                 raw_term_mode.c_cc[VTIME] = 0;
 665                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_term_mode);
 666         } else {
 667                 tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_term_mode);
 668         }
 669 }