contrib/nvi/ex/ex_txt.c

   1 /*-
   2  * Copyright (c) 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1992, 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[] = "@(#)ex_txt.c      10.17 (Berkeley) 10/10/96";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18
  19 #include <bitstring.h>
  20 #include <ctype.h>
  21 #include <limits.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "../common/common.h"
  27
  28 /*
  29  * !!!
  30  * The backslash characters was special when it preceded a newline as part of
  31  * a substitution replacement pattern.  For example, the input ":a\<cr>" would
  32  * failed immediately with an error, as the <cr> wasn't part of a substitution
  33  * replacement pattern.  This implies a frightening integration of the editor
  34  * and the parser and/or the RE engine.  There's no way I'm going to reproduce
  35  * those semantics.
  36  *
  37  * So, if backslashes are special, this code inserts the backslash and the next
  38  * character into the string, without regard for the character or the command
  39  * being entered.  Since "\<cr>" was illegal historically (except for the one
  40  * special case), and the command will fail eventually, no historical scripts
  41  * should break (presuming they didn't depend on the failure mode itself or the
  42  * characters remaining when failure occurred.
  43  */
  44
  45 static int      txt_dent __P((SCR *, TEXT *));
  46 static void     txt_prompt __P((SCR *, TEXT *, ARG_CHAR_T, u_int32_t));
  47
  48 /*
  49  * ex_txt --
  50  *      Get lines from the terminal for ex.
  51  *
  52  * PUBLIC: int ex_txt __P((SCR *, TEXTH *, ARG_CHAR_T, u_int32_t));
  53  */
  54 int
  55 ex_txt(sp, tiqh, prompt, flags)
  56         SCR *sp;
  57         TEXTH *tiqh;
  58         ARG_CHAR_T prompt;
  59         u_int32_t flags;
  60 {
  61         EVENT ev;
  62         GS *gp;
  63         TEXT ait, *ntp, *tp;
  64         carat_t carat_st;
  65         size_t cnt;
  66         int rval;
  67
  68         rval = 0;
  69
  70         /*
  71          * Get a TEXT structure with some initial buffer space, reusing the
  72          * last one if it's big enough.  (All TEXT bookkeeping fields default
  73          * to 0 -- text_init() handles this.)
  74          */
  75         if (tiqh->cqh_first != (void *)tiqh) {
  76                 tp = tiqh->cqh_first;
  77                 if (tp->q.cqe_next != (void *)tiqh || tp->lb_len < 32) {
  78                         text_lfree(tiqh);
  79                         goto newtp;
  80                 }
  81                 tp->len = 0;
  82         } else {
  83 newtp:          if ((tp = text_init(sp, NULL, 0, 32)) == NULL)
  84                         goto err;
  85                 CIRCLEQ_INSERT_HEAD(tiqh, tp, q);
  86         }
  87
  88         /* Set the starting line number. */
  89         tp->lno = sp->lno + 1;
  90
  91         /*
  92          * If it's a terminal, set up autoindent, put out the prompt, and
  93          * set it up so we know we were suspended.  Otherwise, turn off
  94          * the autoindent flag, as that requires less special casing below.
  95          *
  96          * XXX
  97          * Historic practice is that ^Z suspended command mode (but, because
  98          * it ran in cooked mode, it was unaffected by the autowrite option.)
  99          * On restart, any "current" input was discarded, whether in insert
 100          * mode or not, and ex was in command mode.  This code matches historic
 101          * practice, but not 'cause it's easier.
 102          */
 103         gp = sp->gp;
 104         if (F_ISSET(gp, G_SCRIPTED))
 105                 LF_CLR(TXT_AUTOINDENT);
 106         else {
 107                 if (LF_ISSET(TXT_AUTOINDENT)) {
 108                         LF_SET(TXT_EOFCHAR);
 109                         if (v_txt_auto(sp, sp->lno, NULL, 0, tp))
 110                                 goto err;
 111                 }
 112                 txt_prompt(sp, tp, prompt, flags);
 113         }
 114
 115         for (carat_st = C_NOTSET;;) {
 116                 if (v_event_get(sp, &ev, 0, 0))
 117                         goto err;
 118
 119                 /* Deal with all non-character events. */
 120                 switch (ev.e_event) {
 121                 case E_CHARACTER:
 122                         break;
 123                 case E_ERR:
 124                         goto err;
 125                 case E_REPAINT:
 126                 case E_WRESIZE:
 127                         continue;
 128                 case E_EOF:
 129                         rval = 1;
 130                         /* FALLTHROUGH */
 131                 case E_INTERRUPT:
 132                         /*
 133                          * Handle EOF/SIGINT events by discarding partially
 134                          * entered text and returning.  EOF returns failure,
 135                          * E_INTERRUPT returns success.
 136                          */
 137                         goto notlast;
 138                 default:
 139                         v_event_err(sp, &ev);
 140                         goto notlast;
 141                 }
 142
 143                 /*
 144                  * Deal with character events.
 145                  *
 146                  * Check to see if the character fits into the input buffer.
 147                  * (Use tp->len, ignore overwrite and non-printable chars.)
 148                  */
 149                 BINC_GOTO(sp, tp->lb, tp->lb_len, tp->len + 1);
 150
 151                 switch (ev.e_value) {
 152                 case K_CR:
 153                         /*
 154                          * !!!
 155                          * Historically, <carriage-return>'s in the command
 156                          * weren't special, so the ex parser would return an
 157                          * unknown command error message.  However, if they
 158                          * terminated the command if they were in a map.  I'm
 159                          * pretty sure this still isn't right, but it handles
 160                          * what I've seen so far.
 161                          */
 162                         if (!F_ISSET(&ev.e_ch, CH_MAPPED))
 163                                 goto ins_ch;
 164                         /* FALLTHROUGH */
 165                 case K_NL:
 166                         /*
 167                          * '\' can escape <carriage-return>/<newline>.  We
 168                          * don't discard the backslash because we need it
 169                          * to get the <newline> through the ex parser.
 170                          */
 171                         if (LF_ISSET(TXT_BACKSLASH) &&
 172                             tp->len != 0 && tp->lb[tp->len - 1] == '\\')
 173                                 goto ins_ch;
 174
 175                         /*
 176                          * CR returns from the ex command line.
 177                          *
 178                          * XXX
 179                          * Terminate with a nul, needed by filter.
 180                          */
 181                         if (LF_ISSET(TXT_CR)) {
 182                                 tp->lb[tp->len] = '\0';
 183                                 goto done;
 184                         }
 185
 186                         /*
 187                          * '.' may terminate text input mode; free the current
 188                          * TEXT.
 189                          */
 190                         if (LF_ISSET(TXT_DOTTERM) && tp->len == tp->ai + 1 &&
 191                             tp->lb[tp->len - 1] == '.') {
 192 notlast:                        CIRCLEQ_REMOVE(tiqh, tp, q);
 193                                 text_free(tp);
 194                                 goto done;
 195                         }
 196
 197                         /* Set up bookkeeping for the new line. */
 198                         if ((ntp = text_init(sp, NULL, 0, 32)) == NULL)
 199                                 goto err;
 200                         ntp->lno = tp->lno + 1;
 201
 202                         /*
 203                          * Reset the autoindent line value.  0^D keeps the ai
 204                          * line from changing, ^D changes the level, even if
 205                          * there were no characters in the old line.  Note, if
 206                          * using the current tp structure, use the cursor as
 207                          * the length, the autoindent characters may have been
 208                          * erased.
 209                          */
 210                         if (LF_ISSET(TXT_AUTOINDENT)) {
 211                                 if (carat_st == C_NOCHANGE) {
 212                                         if (v_txt_auto(sp,
 213                                             OOBLNO, &ait, ait.ai, ntp))
 214                                                 goto err;
 215                                         free(ait.lb);
 216                                 } else
 217                                         if (v_txt_auto(sp,
 218                                             OOBLNO, tp, tp->len, ntp))
 219                                                 goto err;
 220                                 carat_st = C_NOTSET;
 221                         }
 222                         txt_prompt(sp, ntp, prompt, flags);
 223
 224                         /*
 225                          * Swap old and new TEXT's, and insert the new TEXT
 226                          * into the queue.
 227                          */
 228                         tp = ntp;
 229                         CIRCLEQ_INSERT_TAIL(tiqh, tp, q);
 230                         break;
 231                 case K_CARAT:                   /* Delete autoindent chars. */
 232                         if (tp->len <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
 233                                 carat_st = C_CARATSET;
 234                         goto ins_ch;
 235                 case K_ZERO:                    /* Delete autoindent chars. */
 236                         if (tp->len <= tp->ai && LF_ISSET(TXT_AUTOINDENT))
 237                                 carat_st = C_ZEROSET;
 238                         goto ins_ch;
 239                 case K_CNTRLD:                  /* Delete autoindent char. */
 240                         /*
 241                          * !!!
 242                          * Historically, the ^D command took (but then ignored)
 243                          * a count.  For simplicity, we don't return it unless
 244                          * it's the first character entered.  The check for len
 245                          * equal to 0 is okay, TXT_AUTOINDENT won't be set.
 246                          */
 247                         if (LF_ISSET(TXT_CNTRLD)) {
 248                                 for (cnt = 0; cnt < tp->len; ++cnt)
 249                                         if (!isblank(tp->lb[cnt]))
 250                                                 break;
 251                                 if (cnt == tp->len) {
 252                                         tp->len = 1;
 253                                         tp->lb[0] = ev.e_c;
 254                                         tp->lb[1] = '\0';
 255
 256                                         /*
 257                                          * Put out a line separator, in case
 258                                          * the command fails.
 259                                          */
 260                                         (void)putchar('\n');
 261                                         goto done;
 262                                 }
 263                         }
 264
 265                         /*
 266                          * POSIX 1003.1b-1993, paragraph 7.1.1.9, states that
 267                          * the EOF characters are discarded if there are other
 268                          * characters to process in the line, i.e. if the EOF
 269                          * is not the first character in the line.  For this
 270                          * reason, historic ex discarded the EOF characters,
 271                          * even if occurring in the middle of the input line.
 272                          * We match that historic practice.
 273                          *
 274                          * !!!
 275                          * The test for discarding in the middle of the line is
 276                          * done in the switch, because the CARAT forms are N+1,
 277                          * not N.
 278                          *
 279                          * !!!
 280                          * There's considerable magic to make the terminal code
 281                          * return the EOF character at all.  See that code for
 282                          * details.
 283                          */
 284                         if (!LF_ISSET(TXT_AUTOINDENT) || tp->len == 0)
 285                                 continue;
 286                         switch (carat_st) {
 287                         case C_CARATSET:                /* ^^D */
 288                                 if (tp->len > tp->ai + 1)
 289                                         continue;
 290
 291                                 /* Save the ai string for later. */
 292                                 ait.lb = NULL;
 293                                 ait.lb_len = 0;
 294                                 BINC_GOTO(sp, ait.lb, ait.lb_len, tp->ai);
 295                                 memcpy(ait.lb, tp->lb, tp->ai);
 296                                 ait.ai = ait.len = tp->ai;
 297
 298                                 carat_st = C_NOCHANGE;
 299                                 goto leftmargin;
 300                         case C_ZEROSET:                 /* 0^D */
 301                                 if (tp->len > tp->ai + 1)
 302                                         continue;
 303
 304                                 carat_st = C_NOTSET;
 305 leftmargin:                     (void)gp->scr_ex_adjust(sp, EX_TERM_CE);
 306                                 tp->ai = tp->len = 0;
 307                                 break;
 308                         case C_NOTSET:                  /* ^D */
 309                                 if (tp->len > tp->ai)
 310                                         continue;
 311
 312                                 if (txt_dent(sp, tp))
 313                                         goto err;
 314                                 break;
 315                         default:
 316                                 abort();
 317                         }
 318
 319                         /* Clear and redisplay the line. */
 320                         (void)gp->scr_ex_adjust(sp, EX_TERM_CE);
 321                         txt_prompt(sp, tp, prompt, flags);
 322                         break;
 323                 default:
 324                         /*
 325                          * See the TXT_BEAUTIFY comment in vi/v_txt_ev.c.
 326                          *
 327                          * Silently eliminate any iscntrl() character that was
 328                          * not already handled specially, except for <tab> and
 329                          * <ff>.
 330                          */
 331 ins_ch:                 if (LF_ISSET(TXT_BEAUTIFY) && iscntrl(ev.e_c) &&
 332                             ev.e_value != K_FORMFEED && ev.e_value != K_TAB)
 333                                 break;
 334
 335                         tp->lb[tp->len++] = ev.e_c;
 336                         break;
 337                 }
 338         }
 339         /* NOTREACHED */
 340
 341 done:   return (rval);
 342
 343 err:
 344 alloc_err:
 345         return (1);
 346 }
 347
 348 /*
 349  * txt_prompt --
 350  *      Display the ex prompt, line number, ai characters.  Characters had
 351  *      better be printable by the terminal driver, but that's its problem,
 352  *      not ours.
 353  */
 354 static void
 355 txt_prompt(sp, tp, prompt, flags)
 356         SCR *sp;
 357         TEXT *tp;
 358         ARG_CHAR_T prompt;
 359         u_int32_t flags;
 360 {
 361         /* Display the prompt. */
 362         if (LF_ISSET(TXT_PROMPT))
 363                 (void)printf("%c", prompt);
 364
 365         /* Display the line number. */
 366         if (LF_ISSET(TXT_NUMBER) && O_ISSET(sp, O_NUMBER))
 367                 (void)printf("%6lu  ", (u_long)tp->lno);
 368
 369         /* Print out autoindent string. */
 370         if (LF_ISSET(TXT_AUTOINDENT))
 371                 (void)printf("%.*s", (int)tp->ai, tp->lb);
 372         (void)fflush(stdout);
 373 }
 374
 375 /*
 376  * txt_dent --
 377  *      Handle ^D outdents.
 378  *
 379  * Ex version of vi/v_ntext.c:txt_dent().  See that code for the (usual)
 380  * ranting and raving.  This is a fair bit simpler as ^T isn't special.
 381  */
 382 static int
 383 txt_dent(sp, tp)
 384         SCR *sp;
 385         TEXT *tp;
 386 {
 387         u_long sw, ts;
 388         size_t cno, off, scno, spaces, tabs;
 389
 390         ts = O_VAL(sp, O_TABSTOP);
 391         sw = O_VAL(sp, O_SHIFTWIDTH);
 392
 393         /* Get the current screen column. */
 394         for (off = scno = 0; off < tp->len; ++off)
 395                 if (tp->lb[off] == '\t')
 396                         scno += COL_OFF(scno, ts);
 397                 else
 398                         ++scno;
 399
 400         /* Get the previous shiftwidth column. */
 401         cno = scno;
 402         scno -= --scno % sw;
 403
 404         /*
 405          * Since we don't know what comes before the character(s) being
 406          * deleted, we have to resolve the autoindent characters .  The
 407          * example is a <tab>, which doesn't take up a full shiftwidth
 408          * number of columns because it's preceded by <space>s.  This is
 409          * easy to get if the user sets shiftwidth to a value less than
 410          * tabstop, and then uses ^T to indent, and ^D to outdent.
 411          *
 412          * Count up spaces/tabs needed to get to the target.
 413          */
 414         for (cno = 0, tabs = 0; cno + COL_OFF(cno, ts) <= scno; ++tabs)
 415                 cno += COL_OFF(cno, ts);
 416         spaces = scno - cno;
 417
 418         /* Make sure there's enough room. */
 419         BINC_RET(sp, tp->lb, tp->lb_len, tabs + spaces + 1);
 420
 421         /* Adjust the final ai character count. */
 422         tp->ai = tabs + spaces;
 423
 424         /* Enter the replacement characters. */
 425         for (tp->len = 0; tabs > 0; --tabs)
 426                 tp->lb[tp->len++] = '\t';
 427         for (; spaces > 0; --spaces)
 428                 tp->lb[tp->len++] = ' ';
 429         return (0);
 430 }