1 /* $OpenBSD: cl_screen.c,v 1.28 2017/04/18 01:45:33 deraadt Exp $ */ 2 3 /*- 4 * Copyright (c) 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * Copyright (c) 1993, 1994, 1995, 1996 7 * Keith Bostic. All rights reserved. 8 * 9 * See the LICENSE file for redistribution information. 10 */ 11 12 #include "config.h" 13 14 #include <sys/types.h> 15 #include <sys/queue.h> 16 17 #include <bitstring.h> 18 #include <curses.h> 19 #include <errno.h> 20 #include <signal.h> 21 #include <stdio.h> 22 #include <stdlib.h> 23 #include <string.h> 24 #include <term.h> 25 #include <termios.h> 26 #include <unistd.h> 27 28 #include "../common/common.h" 29 #include "cl.h" 30 31 static int cl_ex_end(GS *); 32 static int cl_ex_init(SCR *); 33 static void cl_freecap(CL_PRIVATE *); 34 static int cl_vi_end(GS *); 35 static int cl_vi_init(SCR *); 36 static int cl_putenv(char *, char *, u_long); 37 38 /* 39 * cl_screen -- 40 * Switch screen types. 41 * 42 * PUBLIC: int cl_screen(SCR *, u_int32_t); 43 */ 44 int 45 cl_screen(SCR *sp, u_int32_t flags) 46 { 47 CL_PRIVATE *clp; 48 GS *gp; 49 50 gp = sp->gp; 51 clp = CLP(sp); 52 53 /* See if the current information is incorrect. */ 54 if (F_ISSET(gp, G_SRESTART)) { 55 if ((!F_ISSET(sp, SC_SCR_EX | SC_SCR_VI) || 56 resizeterm(O_VAL(sp, O_LINES), O_VAL(sp, O_COLUMNS))) && 57 cl_quit(gp)) 58 return (1); 59 F_CLR(gp, G_SRESTART); 60 } 61 62 /* See if we're already in the right mode. */ 63 if ((LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX)) || 64 (LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI))) 65 return (0); 66 67 /* 68 * Fake leaving ex mode. 69 * 70 * We don't actually exit ex or vi mode unless forced (e.g. by a window 71 * size change). This is because many curses implementations can't be 72 * called twice in a single program. Plus, it's faster. If the editor 73 * "leaves" vi to enter ex, when it exits ex we'll just fall back into 74 * vi. 75 */ 76 if (F_ISSET(sp, SC_SCR_EX)) 77 F_CLR(sp, SC_SCR_EX); 78 79 /* 80 * Fake leaving vi mode. 81 * 82 * Clear out the rest of the screen if we're in the middle of a split 83 * screen. Move to the last line in the current screen -- this makes 84 * terminal scrolling happen naturally. Note: *don't* move past the 85 * end of the screen, as there are ex commands (e.g., :read ! cat file) 86 * that don't want to. Don't clear the info line, its contents may be 87 * valid, e.g. :file|append. 88 */ 89 if (F_ISSET(sp, SC_SCR_VI)) { 90 F_CLR(sp, SC_SCR_VI); 91 92 if (TAILQ_NEXT(sp, q)) { 93 (void)move(RLNO(sp, sp->rows), 0); 94 clrtobot(); 95 } 96 (void)move(RLNO(sp, sp->rows) - 1, 0); 97 refresh(); 98 } 99 100 /* Enter the requested mode. */ 101 if (LF_ISSET(SC_EX)) { 102 if (cl_ex_init(sp)) 103 return (1); 104 F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT); 105 106 /* 107 * If doing an ex screen for ex mode, move to the last line 108 * on the screen. 109 */ 110 if (F_ISSET(sp, SC_EX) && clp->cup != NULL) 111 tputs(tgoto(clp->cup, 112 0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar); 113 } else { 114 if (cl_vi_init(sp)) 115 return (1); 116 F_CLR(clp, CL_IN_EX); 117 F_SET(clp, CL_SCR_VI_INIT); 118 } 119 return (0); 120 } 121 122 /* 123 * cl_quit -- 124 * Shutdown the screens. 125 * 126 * PUBLIC: int cl_quit(GS *); 127 */ 128 int 129 cl_quit(GS *gp) 130 { 131 CL_PRIVATE *clp; 132 int rval; 133 134 rval = 0; 135 clp = GCLP(gp); 136 137 /* 138 * If we weren't really running, ignore it. This happens if the 139 * screen changes size before we've called curses. 140 */ 141 if (!F_ISSET(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT)) 142 return (0); 143 144 /* Clean up the terminal mappings. */ 145 if (cl_term_end(gp)) 146 rval = 1; 147 148 /* Really leave vi mode. */ 149 if (F_ISSET(clp, CL_STDIN_TTY) && 150 F_ISSET(clp, CL_SCR_VI_INIT) && cl_vi_end(gp)) 151 rval = 1; 152 153 /* Really leave ex mode. */ 154 if (F_ISSET(clp, CL_STDIN_TTY) && 155 F_ISSET(clp, CL_SCR_EX_INIT) && cl_ex_end(gp)) 156 rval = 1; 157 158 /* 159 * If we were running ex when we quit, or we're using an implementation 160 * of curses where endwin() doesn't get this right, restore the original 161 * terminal modes. 162 * 163 * XXX 164 * We always do this because it's too hard to figure out what curses 165 * implementations get it wrong. It may discard type-ahead characters 166 * from the tty queue. 167 */ 168 if (F_ISSET(clp, CL_STDIN_TTY)) 169 (void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig); 170 171 F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT); 172 return (rval); 173 } 174 175 /* 176 * cl_vi_init -- 177 * Initialize the curses vi screen. 178 */ 179 static int 180 cl_vi_init(SCR *sp) 181 { 182 CL_PRIVATE *clp; 183 char *o_cols, *o_lines, *o_term, *ttype; 184 185 clp = CLP(sp); 186 187 /* If already initialized, just set the terminal modes. */ 188 if (F_ISSET(clp, CL_SCR_VI_INIT)) 189 goto fast; 190 191 /* Curses vi always reads from (and writes to) a terminal. */ 192 if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) { 193 msgq(sp, M_ERR, 194 "Vi's standard input and output must be a terminal"); 195 return (1); 196 } 197 198 /* We'll need a terminal type. */ 199 if (opts_empty(sp, O_TERM, 0)) 200 return (1); 201 ttype = O_STR(sp, O_TERM); 202 203 /* 204 * XXX 205 * Changing the row/column and terminal values is done by putting them 206 * into the environment, which is then read by curses. What this loses 207 * in ugliness, it makes up for in stupidity. We can't simply put the 208 * values into the environment ourselves, because in the presence of a 209 * kernel mechanism for returning the window size, entering values into 210 * the environment will screw up future screen resizing events, e.g. if 211 * the user enters a :shell command and then resizes their window. So, 212 * if they weren't already in the environment, we make sure to delete 213 * them immediately after setting them. 214 * 215 * XXX 216 * Putting the TERM variable into the environment is necessary, even 217 * though we're using newterm() here. We may be using initscr() as 218 * the underlying function. 219 */ 220 o_term = getenv("TERM"); 221 cl_putenv("TERM", ttype, 0); 222 o_lines = getenv("LINES"); 223 cl_putenv("LINES", NULL, (u_long)O_VAL(sp, O_LINES)); 224 o_cols = getenv("COLUMNS"); 225 cl_putenv("COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS)); 226 227 /* 228 * The terminal is aways initialized, either in `main`, or by a 229 * previous call to newterm(3). 230 */ 231 (void)del_curterm(cur_term); 232 233 /* 234 * We don't care about the SCREEN reference returned by newterm, we 235 * never have more than one SCREEN at a time. 236 */ 237 errno = 0; 238 if (newterm(ttype, stdout, stdin) == NULL) { 239 if (errno) 240 msgq(sp, M_SYSERR, "%s", ttype); 241 else 242 msgq(sp, M_ERR, "%s: unknown terminal type", ttype); 243 return (1); 244 } 245 246 if (o_term == NULL) 247 unsetenv("TERM"); 248 if (o_lines == NULL) 249 unsetenv("LINES"); 250 if (o_cols == NULL) 251 unsetenv("COLUMNS"); 252 253 /* 254 * XXX 255 * Someone got let out alone without adult supervision -- the SunOS 256 * newterm resets the signal handlers. There's a race, but it's not 257 * worth closing. 258 */ 259 (void)sig_init(sp->gp, sp); 260 261 /* 262 * We use raw mode. What we want is 8-bit clean, however, signals 263 * and flow control should continue to work. Admittedly, it sounds 264 * like cbreak, but it isn't. Using cbreak() can get you additional 265 * things like IEXTEN, which turns on flags like DISCARD and LNEXT. 266 * 267 * !!! 268 * If raw isn't turning off echo and newlines, something's wrong. 269 * However, it shouldn't hurt. 270 */ 271 noecho(); /* No character echo. */ 272 nonl(); /* No CR/NL translation. */ 273 raw(); /* 8-bit clean. */ 274 idlok(stdscr, 1); /* Use hardware insert/delete line. */ 275 276 /* Put the cursor keys into application mode. */ 277 (void)keypad(stdscr, TRUE); 278 279 /* 280 * XXX 281 * The screen TI sequence just got sent. See the comment in 282 * cl_funcs.c:cl_attr(). 283 */ 284 clp->ti_te = TI_SENT; 285 286 /* 287 * XXX 288 * Historic implementations of curses handled SIGTSTP signals 289 * in one of three ways. They either: 290 * 291 * 1: Set their own handler, regardless. 292 * 2: Did not set a handler if a handler was already installed. 293 * 3: Set their own handler, but then called any previously set 294 * handler after completing their own cleanup. 295 * 296 * We don't try and figure out which behavior is in place, we force 297 * it to SIG_DFL after initializing the curses interface, which means 298 * that curses isn't going to take the signal. Since curses isn't 299 * reentrant (i.e., the whole curses SIGTSTP interface is a fantasy), 300 * we're doing The Right Thing. 301 */ 302 (void)signal(SIGTSTP, SIG_DFL); 303 304 /* 305 * If flow control was on, turn it back on. Turn signals on. ISIG 306 * turns on VINTR, VQUIT, VDSUSP and VSUSP. The main curses code 307 * already installed a handler for VINTR. We're going to disable the 308 * other three. 309 * 310 * XXX 311 * We want to use ^Y as a vi scrolling command. If the user has the 312 * DSUSP character set to ^Y (common practice) clean it up. As it's 313 * equally possible that the user has VDSUSP set to 'a', we disable 314 * it regardless. It doesn't make much sense to suspend vi at read, 315 * so I don't think anyone will care. Alternatively, we could look 316 * it up in the table of legal command characters and turn it off if 317 * it matches one. 318 * 319 * XXX 320 * We don't check to see if the user had signals enabled originally. 321 * If they didn't, it's unclear what we're supposed to do here, but 322 * it's also pretty unlikely. 323 */ 324 if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) { 325 msgq(sp, M_SYSERR, "tcgetattr"); 326 goto err; 327 } 328 if (clp->orig.c_iflag & IXON) 329 clp->vi_enter.c_iflag |= IXON; 330 if (clp->orig.c_iflag & IXOFF) 331 clp->vi_enter.c_iflag |= IXOFF; 332 333 clp->vi_enter.c_lflag |= ISIG; 334 clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE; 335 clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE; 336 clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE; 337 338 /* 339 * XXX 340 * OSF/1 doesn't turn off the <discard>, <literal-next> or <status> 341 * characters when curses switches into raw mode. It should be OK 342 * to do it explicitly for everyone. 343 */ 344 clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE; 345 clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE; 346 clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE; 347 348 /* Initialize terminal based information. */ 349 if (cl_term_init(sp)) 350 goto err; 351 352 fast: /* Set the terminal modes. */ 353 if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) { 354 if (errno == EINTR) 355 goto fast; 356 msgq(sp, M_SYSERR, "tcsetattr"); 357 err: (void)cl_vi_end(sp->gp); 358 return (1); 359 } 360 return (0); 361 } 362 363 /* 364 * cl_vi_end -- 365 * Shutdown the vi screen. 366 */ 367 static int 368 cl_vi_end(GS *gp) 369 { 370 CL_PRIVATE *clp; 371 372 clp = GCLP(gp); 373 374 /* Restore the cursor keys to normal mode. */ 375 (void)keypad(stdscr, FALSE); 376 377 /* 378 * If we were running vi when we quit, scroll the screen up a single 379 * line so we don't lose any information. 380 * 381 * Move to the bottom of the window (some endwin implementations don't 382 * do this for you). 383 */ 384 if (!F_ISSET(clp, CL_IN_EX)) { 385 (void)move(0, 0); 386 (void)deleteln(); 387 (void)move(LINES - 1, 0); 388 (void)refresh(); 389 } 390 391 cl_freecap(clp); 392 393 /* End curses window. */ 394 (void)endwin(); 395 396 /* Free the SCREEN created by newterm(3). */ 397 delscreen(set_term(NULL)); 398 399 /* 400 * XXX 401 * The screen TE sequence just got sent. See the comment in 402 * cl_funcs.c:cl_attr(). 403 */ 404 clp->ti_te = TE_SENT; 405 406 return (0); 407 } 408 409 /* 410 * cl_ex_init -- 411 * Initialize the ex screen. 412 */ 413 static int 414 cl_ex_init(SCR *sp) 415 { 416 CL_PRIVATE *clp; 417 418 clp = CLP(sp); 419 420 /* If already initialized, just set the terminal modes. */ 421 if (F_ISSET(clp, CL_SCR_EX_INIT)) 422 goto fast; 423 424 /* If not reading from a file, we're done. */ 425 if (!F_ISSET(clp, CL_STDIN_TTY)) 426 return (0); 427 428 /* Get the ex termcap/terminfo strings. */ 429 (void)cl_getcap(sp, "cup", &clp->cup); 430 (void)cl_getcap(sp, "smso", &clp->smso); 431 (void)cl_getcap(sp, "rmso", &clp->rmso); 432 (void)cl_getcap(sp, "el", &clp->el); 433 (void)cl_getcap(sp, "cuu1", &clp->cuu1); 434 435 /* Enter_standout_mode and exit_standout_mode are paired. */ 436 if (clp->smso == NULL || clp->rmso == NULL) { 437 free(clp->smso); 438 clp->smso = NULL; 439 free(clp->rmso); 440 clp->rmso = NULL; 441 } 442 443 /* 444 * Turn on canonical mode, with normal input and output processing. 445 * Start with the original terminal settings as the user probably 446 * had them (including any local extensions) set correctly for the 447 * current terminal. 448 * 449 * !!! 450 * We can't get everything that we need portably; for example, ONLCR, 451 * mapping <newline> to <carriage-return> on output isn't required 452 * by POSIX 1003.1b-1993. If this turns out to be a problem, then 453 * we'll either have to play some games on the mapping, or we'll have 454 * to make all ex printf's output \r\n instead of \n. 455 */ 456 clp->ex_enter = clp->orig; 457 clp->ex_enter.c_lflag |= 458 ECHO | ECHOCTL | ECHOE | ECHOK | ECHOKE | ICANON | IEXTEN | ISIG; 459 clp->ex_enter.c_iflag |= ICRNL; 460 clp->ex_enter.c_oflag |= ONLCR | OPOST; 461 462 fast: if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) { 463 if (errno == EINTR) 464 goto fast; 465 msgq(sp, M_SYSERR, "tcsetattr"); 466 return (1); 467 } 468 return (0); 469 } 470 471 /* 472 * cl_ex_end -- 473 * Shutdown the ex screen. 474 */ 475 static int 476 cl_ex_end(GS *gp) 477 { 478 CL_PRIVATE *clp; 479 480 clp = GCLP(gp); 481 482 cl_freecap(clp); 483 484 return (0); 485 } 486 487 /* 488 * cl_getcap -- 489 * Retrieve termcap/terminfo strings. 490 * 491 * PUBLIC: int cl_getcap(SCR *, char *, char **); 492 */ 493 int 494 cl_getcap(SCR *sp, char *name, char **elementp) 495 { 496 size_t len; 497 char *t; 498 499 if ((t = tigetstr(name)) != NULL && 500 t != (char *)-1 && (len = strlen(t)) != 0) { 501 MALLOC_RET(sp, *elementp, len + 1); 502 memmove(*elementp, t, len + 1); 503 } 504 return (0); 505 } 506 507 /* 508 * cl_freecap -- 509 * Free any allocated termcap/terminfo strings. 510 */ 511 static void 512 cl_freecap(CL_PRIVATE *clp) 513 { 514 free(clp->el); 515 clp->el = NULL; 516 free(clp->cup); 517 clp->cup = NULL; 518 free(clp->cuu1); 519 clp->cuu1 = NULL; 520 free(clp->rmso); 521 clp->rmso = NULL; 522 free(clp->smso); 523 clp->smso = NULL; 524 } 525 526 /* 527 * cl_putenv -- 528 * Put a value into the environment. 529 */ 530 static int 531 cl_putenv(char *name, char *str, u_long value) 532 { 533 char buf[40]; 534 535 if (str == NULL) { 536 (void)snprintf(buf, sizeof(buf), "%lu", value); 537 return (setenv(name, buf, 1)); 538 } else 539 return (setenv(name, str, 1)); 540 } 541