cl/cl_screen.c

   1 /*-
   2  * Copyright (c) 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * See the LICENSE file for redistribution information.
   8  */
   9
  10 #include "config.h"
  11
  12 #ifndef lint
  13 static const char sccsid[] = "$Id: cl_screen.c,v 10.56 2002/05/03 19:59:44 skimo Exp $ (Berkeley) $Date: 2002/05/03 19:59:44 $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18
  19 #include <bitstring.h>
  20 #include <errno.h>
  21 #include <signal.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.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 __P((GS *));
  32 static int      cl_ex_init __P((SCR *));
  33 static void     cl_freecap __P((CL_PRIVATE *));
  34 static int      cl_vi_end __P((GS *));
  35 static int      cl_vi_init __P((SCR *));
  36 static int      cl_putenv __P((SCR *sp, char *, char *, u_long));
  37
  38 /*
  39  * cl_screen --
  40  *      Switch screen types.
  41  *
  42  * PUBLIC: int cl_screen __P((SCR *, u_int32_t));
  43  */
  44 int
  45 cl_screen(SCR *sp, u_int32_t flags)
  46 {
  47         CL_PRIVATE *clp;
  48         WINDOW *win;
  49         GS *gp;
  50
  51         gp = sp->gp;
  52         clp = CLP(sp);
  53         win = CLSP(sp) ? CLSP(sp) : stdscr;
  54
  55         /* See if the current information is incorrect. */
  56         if (F_ISSET(gp, G_SRESTART)) {
  57                 if (CLSP(sp)) {
  58                     delwin(CLSP(sp));
  59                     sp->cl_private = NULL;
  60                 }
  61                 if (cl_quit(gp))
  62                         return (1);
  63                 F_CLR(gp, G_SRESTART);
  64         }
  65
  66         /* See if we're already in the right mode. */
  67         if ((LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX)) ||
  68             (LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI)))
  69                 return (0);
  70
  71         /*
  72          * Fake leaving ex mode.
  73          *
  74          * We don't actually exit ex or vi mode unless forced (e.g. by a window
  75          * size change).  This is because many curses implementations can't be
  76          * called twice in a single program.  Plus, it's faster.  If the editor
  77          * "leaves" vi to enter ex, when it exits ex we'll just fall back into
  78          * vi.
  79          */
  80         if (F_ISSET(sp, SC_SCR_EX))
  81                 F_CLR(sp, SC_SCR_EX);
  82
  83         /*
  84          * Fake leaving vi mode.
  85          *
  86          * Clear out the rest of the screen if we're in the middle of a split
  87          * screen.  Move to the last line in the current screen -- this makes
  88          * terminal scrolling happen naturally.  Note: *don't* move past the
  89          * end of the screen, as there are ex commands (e.g., :read ! cat file)
  90          * that don't want to.  Don't clear the info line, its contents may be
  91          * valid, e.g. :file|append.
  92          */
  93         if (F_ISSET(sp, SC_SCR_VI)) {
  94                 F_CLR(sp, SC_SCR_VI);
  95
  96                 if (sp->q.cqe_next != (void *)&sp->wp->scrq) {
  97                         (void)wmove(win, RLNO(sp, sp->rows), 0);
  98                         wclrtobot(win);
  99                 }
 100                 (void)wmove(win, RLNO(sp, sp->rows) - 1, 0);
 101                 wrefresh(win);
 102         }
 103
 104         /* Enter the requested mode. */
 105         if (LF_ISSET(SC_EX)) {
 106                 if (cl_ex_init(sp))
 107                         return (1);
 108                 F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);
 109
 110                 /*
 111                  * If doing an ex screen for ex mode, move to the last line
 112                  * on the screen.
 113                  */
 114                 if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
 115                         tputs(tgoto(clp->cup,
 116                             0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
 117         } else {
 118                 if (cl_vi_init(sp))
 119                         return (1);
 120                 F_CLR(clp, CL_IN_EX);
 121                 F_SET(clp, CL_SCR_VI_INIT);
 122         }
 123         return (0);
 124 }
 125
 126 /*
 127  * cl_quit --
 128  *      Shutdown the screens.
 129  *
 130  * PUBLIC: int cl_quit __P((GS *));
 131  */
 132 int
 133 cl_quit(GS *gp)
 134 {
 135         CL_PRIVATE *clp;
 136         int rval;
 137
 138         rval = 0;
 139         clp = GCLP(gp);
 140
 141         /*
 142          * If we weren't really running, ignore it.  This happens if the
 143          * screen changes size before we've called curses.
 144          */
 145         if (!F_ISSET(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT))
 146                 return (0);
 147
 148         /* Clean up the terminal mappings. */
 149         if (cl_term_end(gp))
 150                 rval = 1;
 151
 152         /* Really leave vi mode. */
 153         if (F_ISSET(clp, CL_STDIN_TTY) &&
 154             F_ISSET(clp, CL_SCR_VI_INIT) && cl_vi_end(gp))
 155                 rval = 1;
 156
 157         /* Really leave ex mode. */
 158         if (F_ISSET(clp, CL_STDIN_TTY) &&
 159             F_ISSET(clp, CL_SCR_EX_INIT) && cl_ex_end(gp))
 160                 rval = 1;
 161
 162         /*
 163          * If we were running ex when we quit, or we're using an implementation
 164          * of curses where endwin() doesn't get this right, restore the original
 165          * terminal modes.
 166          *
 167          * XXX
 168          * We always do this because it's too hard to figure out what curses
 169          * implementations get it wrong.  It may discard type-ahead characters
 170          * from the tty queue.
 171          */
 172         (void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig);
 173
 174         F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
 175         return (rval);
 176 }
 177
 178 /*
 179  * cl_vi_init --
 180  *      Initialize the curses vi screen.
 181  */
 182 static int
 183 cl_vi_init(SCR *sp)
 184 {
 185         CL_PRIVATE *clp;
 186         GS *gp;
 187         char *o_cols, *o_lines, *o_term, *ttype;
 188
 189         gp = sp->gp;
 190         clp = CLP(sp);
 191
 192         /* If already initialized, just set the terminal modes. */
 193         if (F_ISSET(clp, CL_SCR_VI_INIT))
 194                 goto fast;
 195
 196         /* Curses vi always reads from (and writes to) a terminal. */
 197         if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) {
 198                 msgq(sp, M_ERR,
 199                     "016|Vi's standard input and output must be a terminal");
 200                 return (1);
 201         }
 202
 203         /* We'll need a terminal type. */
 204         if (opts_empty(sp, O_TERM, 0))
 205                 return (1);
 206         ttype = O_STR(sp, O_TERM);
 207
 208         /*
 209          * XXX
 210          * Changing the row/column and terminal values is done by putting them
 211          * into the environment, which is then read by curses.  What this loses
 212          * in ugliness, it makes up for in stupidity.  We can't simply put the
 213          * values into the environment ourselves, because in the presence of a
 214          * kernel mechanism for returning the window size, entering values into
 215          * the environment will screw up future screen resizing events, e.g. if
 216          * the user enters a :shell command and then resizes their window.  So,
 217          * if they weren't already in the environment, we make sure to delete
 218          * them immediately after setting them.
 219          *
 220          * XXX
 221          * Putting the TERM variable into the environment is necessary, even
 222          * though we're using newterm() here.  We may be using initscr() as
 223          * the underlying function.
 224          */
 225         o_term = getenv("TERM");
 226         cl_putenv(sp, "TERM", ttype, 0);
 227         o_lines = getenv("LINES");
 228         cl_putenv(sp, "LINES", NULL, (u_long)O_VAL(sp, O_LINES));
 229         o_cols = getenv("COLUMNS");
 230         cl_putenv(sp, "COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS));
 231
 232         /*
 233          * We don't care about the SCREEN reference returned by newterm, we
 234          * never have more than one SCREEN at a time.
 235          *
 236          * XXX
 237          * The SunOS initscr() can't be called twice.  Don't even think about
 238          * using it.  It fails in subtle ways (e.g. select(2) on fileno(stdin)
 239          * stops working).  (The SVID notes that applications should only call
 240          * initscr() once.)
 241          *
 242          * XXX
 243          * The HP/UX newterm doesn't support the NULL first argument, so we
 244          * have to specify the terminal type.
 245          */
 246         errno = 0;
 247         if (newterm(ttype, stdout, stdin) == NULL) {
 248                 if (errno)
 249                         msgq(sp, M_SYSERR, "%s", ttype);
 250                 else
 251                         msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
 252                 return (1);
 253         }
 254
 255         if (o_term == NULL)
 256                 cl_unsetenv(sp, "TERM");
 257         if (o_lines == NULL)
 258                 cl_unsetenv(sp, "LINES");
 259         if (o_cols == NULL)
 260                 cl_unsetenv(sp, "COLUMNS");
 261
 262         /*
 263          * XXX
 264          * Someone got let out alone without adult supervision -- the SunOS
 265          * newterm resets the signal handlers.  There's a race, but it's not
 266          * worth closing.
 267          */
 268         (void)sig_init(sp->gp, sp);
 269
 270         /*
 271          * We use raw mode.  What we want is 8-bit clean, however, signals
 272          * and flow control should continue to work.  Admittedly, it sounds
 273          * like cbreak, but it isn't.  Using cbreak() can get you additional
 274          * things like IEXTEN, which turns on flags like DISCARD and LNEXT.
 275          *
 276          * !!!
 277          * If raw isn't turning off echo and newlines, something's wrong.
 278          * However, it shouldn't hurt.
 279          */
 280         noecho();                       /* No character echo. */
 281         nonl();                         /* No CR/NL translation. */
 282         raw();                          /* 8-bit clean. */
 283         idlok(stdscr, 1);               /* Use hardware insert/delete line. */
 284
 285         /* Put the cursor keys into application mode. */
 286         (void)keypad(stdscr, TRUE);
 287
 288         /*
 289          * XXX
 290          * The screen TI sequence just got sent.  See the comment in
 291          * cl_funcs.c:cl_attr().
 292          */
 293         clp->ti_te = TI_SENT;
 294
 295         /*
 296          * XXX
 297          * Historic implementations of curses handled SIGTSTP signals
 298          * in one of three ways.  They either:
 299          *
 300          *      1: Set their own handler, regardless.
 301          *      2: Did not set a handler if a handler was already installed.
 302          *      3: Set their own handler, but then called any previously set
 303          *         handler after completing their own cleanup.
 304          *
 305          * We don't try and figure out which behavior is in place, we force
 306          * it to SIG_DFL after initializing the curses interface, which means
 307          * that curses isn't going to take the signal.  Since curses isn't
 308          * reentrant (i.e., the whole curses SIGTSTP interface is a fantasy),
 309          * we're doing The Right Thing.
 310          */
 311         (void)signal(SIGTSTP, SIG_DFL);
 312
 313         /*
 314          * If flow control was on, turn it back on.  Turn signals on.  ISIG
 315          * turns on VINTR, VQUIT, VDSUSP and VSUSP.   The main curses code
 316          * already installed a handler for VINTR.  We're going to disable the
 317          * other three.
 318          *
 319          * XXX
 320          * We want to use ^Y as a vi scrolling command.  If the user has the
 321          * DSUSP character set to ^Y (common practice) clean it up.  As it's
 322          * equally possible that the user has VDSUSP set to 'a', we disable
 323          * it regardless.  It doesn't make much sense to suspend vi at read,
 324          * so I don't think anyone will care.  Alternatively, we could look
 325          * it up in the table of legal command characters and turn it off if
 326          * it matches one.  VDSUSP wasn't in POSIX 1003.1-1990, so we test for
 327          * it.
 328          *
 329          * XXX
 330          * We don't check to see if the user had signals enabled originally.
 331          * If they didn't, it's unclear what we're supposed to do here, but
 332          * it's also pretty unlikely.
 333          */
 334         if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) {
 335                 msgq(sp, M_SYSERR, "tcgetattr");
 336                 goto err;
 337         }
 338         if (clp->orig.c_iflag & IXON)
 339                 clp->vi_enter.c_iflag |= IXON;
 340         if (clp->orig.c_iflag & IXOFF)
 341                 clp->vi_enter.c_iflag |= IXOFF;
 342
 343         clp->vi_enter.c_lflag |= ISIG;
 344 #ifdef VDSUSP
 345         clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE;
 346 #endif
 347         clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE;
 348         clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE;
 349
 350         /*
 351          * XXX
 352          * OSF/1 doesn't turn off the <discard>, <literal-next> or <status>
 353          * characters when curses switches into raw mode.  It should be OK
 354          * to do it explicitly for everyone.
 355          */
 356 #ifdef VDISCARD
 357         clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE;
 358 #endif
 359 #ifdef VLNEXT
 360         clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE;
 361 #endif
 362 #ifdef VSTATUS
 363         clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE;
 364 #endif
 365
 366         /* Initialize terminal based information. */
 367         if (cl_term_init(sp))
 368                 goto err;
 369
 370 fast:   /* Set the terminal modes. */
 371         if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) {
 372                 if (errno == EINTR)
 373                         goto fast;
 374                 msgq(sp, M_SYSERR, "tcsetattr");
 375 err:            (void)cl_vi_end(sp->gp);
 376                 return (1);
 377         }
 378         return (0);
 379 }
 380
 381 /*
 382  * cl_vi_end --
 383  *      Shutdown the vi screen.
 384  */
 385 static int
 386 cl_vi_end(GS *gp)
 387 {
 388         CL_PRIVATE *clp;
 389
 390         clp = GCLP(gp);
 391
 392         /* Restore the cursor keys to normal mode. */
 393         (void)keypad(stdscr, FALSE);
 394
 395         /*
 396          * If we were running vi when we quit, scroll the screen up a single
 397          * line so we don't lose any information.
 398          *
 399          * Move to the bottom of the window (some endwin implementations don't
 400          * do this for you).
 401          */
 402         if (!F_ISSET(clp, CL_IN_EX)) {
 403                 (void)move(0, 0);
 404                 (void)deleteln();
 405                 (void)move(LINES - 1, 0);
 406                 (void)refresh();
 407         }
 408
 409         cl_freecap(clp);
 410
 411         /* End curses window. */
 412         (void)endwin();
 413
 414         /*
 415          * XXX
 416          * The screen TE sequence just got sent.  See the comment in
 417          * cl_funcs.c:cl_attr().
 418          */
 419         clp->ti_te = TE_SENT;
 420
 421         return (0);
 422 }
 423
 424 /*
 425  * cl_ex_init --
 426  *      Initialize the ex screen.
 427  */
 428 static int
 429 cl_ex_init(SCR *sp)
 430 {
 431         CL_PRIVATE *clp;
 432
 433         clp = CLP(sp);
 434
 435         /* If already initialized, just set the terminal modes. */
 436         if (F_ISSET(clp, CL_SCR_EX_INIT))
 437                 goto fast;
 438
 439         /* If not reading from a file, we're done. */
 440         if (!F_ISSET(clp, CL_STDIN_TTY))
 441                 return (0);
 442
 443         /* Get the ex termcap/terminfo strings. */
 444         (void)cl_getcap(sp, "cup", &clp->cup);
 445         (void)cl_getcap(sp, "smso", &clp->smso);
 446         (void)cl_getcap(sp, "rmso", &clp->rmso);
 447         (void)cl_getcap(sp, "el", &clp->el);
 448         (void)cl_getcap(sp, "cuu1", &clp->cuu1);
 449
 450         /* Enter_standout_mode and exit_standout_mode are paired. */
 451         if (clp->smso == NULL || clp->rmso == NULL) {
 452                 if (clp->smso != NULL) {
 453                         free(clp->smso);
 454                         clp->smso = NULL;
 455                 }
 456                 if (clp->rmso != NULL) {
 457                         free(clp->rmso);
 458                         clp->rmso = NULL;
 459                 }
 460         }
 461
 462         /*
 463          * Turn on canonical mode, with normal input and output processing.
 464          * Start with the original terminal settings as the user probably
 465          * had them (including any local extensions) set correctly for the
 466          * current terminal.
 467          *
 468          * !!!
 469          * We can't get everything that we need portably; for example, ONLCR,
 470          * mapping <newline> to <carriage-return> on output isn't required
 471          * by POSIX 1003.1b-1993.  If this turns out to be a problem, then
 472          * we'll either have to play some games on the mapping, or we'll have
 473          * to make all ex printf's output \r\n instead of \n.
 474          */
 475         clp->ex_enter = clp->orig;
 476         clp->ex_enter.c_lflag  |= ECHO | ECHOE | ECHOK | ICANON | IEXTEN | ISIG;
 477 #ifdef ECHOCTL
 478         clp->ex_enter.c_lflag |= ECHOCTL;
 479 #endif
 480 #ifdef ECHOKE
 481         clp->ex_enter.c_lflag |= ECHOKE;
 482 #endif
 483         clp->ex_enter.c_iflag |= ICRNL;
 484         clp->ex_enter.c_oflag |= OPOST;
 485 #ifdef ONLCR
 486         clp->ex_enter.c_oflag |= ONLCR;
 487 #endif
 488
 489 fast:   if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) {
 490                 if (errno == EINTR)
 491                         goto fast;
 492                 msgq(sp, M_SYSERR, "tcsetattr");
 493                 return (1);
 494         }
 495         return (0);
 496 }
 497
 498 /*
 499  * cl_ex_end --
 500  *      Shutdown the ex screen.
 501  */
 502 static int
 503 cl_ex_end(GS *gp)
 504 {
 505         CL_PRIVATE *clp;
 506
 507         clp = GCLP(gp);
 508
 509         cl_freecap(clp);
 510
 511         return (0);
 512 }
 513
 514 /*
 515  * cl_getcap --
 516  *      Retrieve termcap/terminfo strings.
 517  *
 518  * PUBLIC: int cl_getcap __P((SCR *, char *, char **));
 519  */
 520 int
 521 cl_getcap(SCR *sp, char *name, char **elementp)
 522 {
 523         size_t len;
 524         char *t;
 525
 526         if ((t = tigetstr(name)) != NULL &&
 527             t != (char *)-1 && (len = strlen(t)) != 0) {
 528                 MALLOC_RET(sp, *elementp, char *, len + 1);
 529                 memmove(*elementp, t, len + 1);
 530         }
 531         return (0);
 532 }
 533
 534 /*
 535  * cl_freecap --
 536  *      Free any allocated termcap/terminfo strings.
 537  */
 538 static void
 539 cl_freecap(CL_PRIVATE *clp)
 540 {
 541         if (clp->el != NULL) {
 542                 free(clp->el);
 543                 clp->el = NULL;
 544         }
 545         if (clp->cup != NULL) {
 546                 free(clp->cup);
 547                 clp->cup = NULL;
 548         }
 549         if (clp->cuu1 != NULL) {
 550                 free(clp->cuu1);
 551                 clp->cuu1 = NULL;
 552         }
 553         if (clp->rmso != NULL) {
 554                 free(clp->rmso);
 555                 clp->rmso = NULL;
 556         }
 557         if (clp->smso != NULL) {
 558                 free(clp->smso);
 559                 clp->smso = NULL;
 560         }
 561 }
 562
 563 /*
 564  * cl_putenv --
 565  *      Put a value into the environment.
 566  */
 567 static int
 568 cl_putenv(SCR *sp, char *name, char *str, u_long value)
 569 {
 570         char buf[40];
 571
 572         if (str == NULL) {
 573                 (void)snprintf(buf, sizeof(buf), "%lu", value);
 574                 return (cl_setenv(sp, name, buf));
 575         } else
 576                 return (cl_setenv(sp, name, str));
 577 }