1 /* $FreeBSD$ */ 2 /* 3 * Copyright (C) 1984-2011 Mark Nudelman 4 * 5 * You may distribute under the terms of either the GNU General Public 6 * License or the Less License, as specified in the README file. 7 * 8 * For more information about less, or for information on how to 9 * contact the author, see the README file. 10 */ 11 12 13 /* 14 * Routines to manipulate the "line buffer". 15 * The line buffer holds a line of output as it is being built 16 * in preparation for output to the screen. 17 */ 18 19 #include "less.h" 20 #include "charset.h" 21 22 static char *linebuf = NULL; /* Buffer which holds the current output line */ 23 static char *attr = NULL; /* Extension of linebuf to hold attributes */ 24 public int size_linebuf = 0; /* Size of line buffer (and attr buffer) */ 25 26 static int cshift; /* Current left-shift of output line buffer */ 27 public int hshift; /* Desired left-shift of output line buffer */ 28 public int tabstops[TABSTOP_MAX] = { 0 }; /* Custom tabstops */ 29 public int ntabstops = 1; /* Number of tabstops */ 30 public int tabdefault = 8; /* Default repeated tabstops */ 31 32 static int curr; /* Index into linebuf */ 33 static int column; /* Printable length, accounting for 34 backspaces, etc. */ 35 static int overstrike; /* Next char should overstrike previous char */ 36 static int last_overstrike = AT_NORMAL; 37 static int is_null_line; /* There is no current line */ 38 static int lmargin; /* Left margin */ 39 static char pendc; 40 static POSITION pendpos; 41 static char *end_ansi_chars; 42 static char *mid_ansi_chars; 43 44 static int attr_swidth(); 45 static int attr_ewidth(); 46 static int do_append(); 47 48 extern int sigs; 49 extern int bs_mode; 50 extern int linenums; 51 extern int ctldisp; 52 extern int twiddle; 53 extern int binattr; 54 extern int status_col; 55 extern int auto_wrap, ignaw; 56 extern int bo_s_width, bo_e_width; 57 extern int ul_s_width, ul_e_width; 58 extern int bl_s_width, bl_e_width; 59 extern int so_s_width, so_e_width; 60 extern int sc_width, sc_height; 61 extern int utf_mode; 62 extern POSITION start_attnpos; 63 extern POSITION end_attnpos; 64 65 static char mbc_buf[MAX_UTF_CHAR_LEN]; 66 static int mbc_buf_len = 0; 67 static int mbc_buf_index = 0; 68 static POSITION mbc_pos; 69 70 /* 71 * Initialize from environment variables. 72 */ 73 public void 74 init_line() 75 { 76 end_ansi_chars = lgetenv("LESSANSIENDCHARS"); 77 if (end_ansi_chars == NULL || *end_ansi_chars == '\0') 78 end_ansi_chars = "m"; 79 80 mid_ansi_chars = lgetenv("LESSANSIMIDCHARS"); 81 if (mid_ansi_chars == NULL || *mid_ansi_chars == '\0') 82 mid_ansi_chars = "0123456789;[?!\"'#%()*+ "; 83 84 linebuf = (char *) ecalloc(LINEBUF_SIZE, sizeof(char)); 85 attr = (char *) ecalloc(LINEBUF_SIZE, sizeof(char)); 86 size_linebuf = LINEBUF_SIZE; 87 } 88 89 /* 90 * Expand the line buffer. 91 */ 92 static int 93 expand_linebuf() 94 { 95 /* Double the size of the line buffer. */ 96 int new_size = size_linebuf * 2; 97 98 /* Just realloc to expand the buffer, if we can. */ 99 #if HAVE_REALLOC 100 char *new_buf = (char *) realloc(linebuf, new_size); 101 char *new_attr = (char *) realloc(attr, new_size); 102 #else 103 char *new_buf = (char *) calloc(new_size, sizeof(char)); 104 char *new_attr = (char *) calloc(new_size, sizeof(char)); 105 #endif 106 if (new_buf == NULL || new_attr == NULL) 107 { 108 if (new_attr != NULL) 109 free(new_attr); 110 if (new_buf != NULL) 111 free(new_buf); 112 return 1; 113 } 114 #if HAVE_REALLOC 115 /* 116 * We realloc'd the buffers; they already have the old contents. 117 */ 118 #if 0 119 memset(new_buf + size_linebuf, 0, new_size - size_linebuf); 120 memset(new_attr + size_linebuf, 0, new_size - size_linebuf); 121 #endif 122 #else 123 /* 124 * We just calloc'd the buffers; copy the old contents. 125 */ 126 memcpy(new_buf, linebuf, size_linebuf * sizeof(char)); 127 memcpy(new_attr, attr, size_linebuf * sizeof(char)); 128 free(attr); 129 free(linebuf); 130 #endif 131 linebuf = new_buf; 132 attr = new_attr; 133 size_linebuf = new_size; 134 return 0; 135 } 136 137 /* 138 * Is a character ASCII? 139 */ 140 public int 141 is_ascii_char(ch) 142 LWCHAR ch; 143 { 144 return (ch <= 0x7F); 145 } 146 147 /* 148 * Rewind the line buffer. 149 */ 150 public void 151 prewind() 152 { 153 curr = 0; 154 column = 0; 155 cshift = 0; 156 overstrike = 0; 157 last_overstrike = AT_NORMAL; 158 mbc_buf_len = 0; 159 is_null_line = 0; 160 pendc = '\0'; 161 lmargin = 0; 162 if (status_col) 163 lmargin += 1; 164 } 165 166 /* 167 * Insert the line number (of the given position) into the line buffer. 168 */ 169 public void 170 plinenum(pos) 171 POSITION pos; 172 { 173 register LINENUM linenum = 0; 174 register int i; 175 176 if (linenums == OPT_ONPLUS) 177 { 178 /* 179 * Get the line number and put it in the current line. 180 * {{ Note: since find_linenum calls forw_raw_line, 181 * it may seek in the input file, requiring the caller 182 * of plinenum to re-seek if necessary. }} 183 * {{ Since forw_raw_line modifies linebuf, we must 184 * do this first, before storing anything in linebuf. }} 185 */ 186 linenum = find_linenum(pos); 187 } 188 189 /* 190 * Display a status column if the -J option is set. 191 */ 192 if (status_col) 193 { 194 linebuf[curr] = ' '; 195 if (start_attnpos != NULL_POSITION && 196 pos >= start_attnpos && pos < end_attnpos) 197 attr[curr] = AT_NORMAL|AT_HILITE; 198 else 199 attr[curr] = AT_NORMAL; 200 curr++; 201 column++; 202 } 203 /* 204 * Display the line number at the start of each line 205 * if the -N option is set. 206 */ 207 if (linenums == OPT_ONPLUS) 208 { 209 char buf[INT_STRLEN_BOUND(pos) + 2]; 210 int n; 211 212 linenumtoa(linenum, buf); 213 n = strlen(buf); 214 if (n < MIN_LINENUM_WIDTH) 215 n = MIN_LINENUM_WIDTH; 216 sprintf(linebuf+curr, "%*s ", n, buf); 217 n++; /* One space after the line number. */ 218 for (i = 0; i < n; i++) 219 attr[curr+i] = AT_NORMAL; 220 curr += n; 221 column += n; 222 lmargin += n; 223 } 224 225 /* 226 * Append enough spaces to bring us to the lmargin. 227 */ 228 while (column < lmargin) 229 { 230 linebuf[curr] = ' '; 231 attr[curr++] = AT_NORMAL; 232 column++; 233 } 234 } 235 236 /* 237 * Shift the input line left. 238 * This means discarding N printable chars at the start of the buffer. 239 */ 240 static void 241 pshift(shift) 242 int shift; 243 { 244 LWCHAR prev_ch = 0; 245 unsigned char c; 246 int shifted = 0; 247 int to; 248 int from; 249 int len; 250 int width; 251 int prev_attr; 252 int next_attr; 253 254 if (shift > column - lmargin) 255 shift = column - lmargin; 256 if (shift > curr - lmargin) 257 shift = curr - lmargin; 258 259 to = from = lmargin; 260 /* 261 * We keep on going when shifted == shift 262 * to get all combining chars. 263 */ 264 while (shifted <= shift && from < curr) 265 { 266 c = linebuf[from]; 267 if (ctldisp == OPT_ONPLUS && IS_CSI_START(c)) 268 { 269 /* Keep cumulative effect. */ 270 linebuf[to] = c; 271 attr[to++] = attr[from++]; 272 while (from < curr && linebuf[from]) 273 { 274 linebuf[to] = linebuf[from]; 275 attr[to++] = attr[from]; 276 if (!is_ansi_middle(linebuf[from++])) 277 break; 278 } 279 continue; 280 } 281 282 width = 0; 283 284 if (!IS_ASCII_OCTET(c) && utf_mode) 285 { 286 /* Assumes well-formedness validation already done. */ 287 LWCHAR ch; 288 289 len = utf_len(c); 290 if (from + len > curr) 291 break; 292 ch = get_wchar(linebuf + from); 293 if (!is_composing_char(ch) && !is_combining_char(prev_ch, ch)) 294 width = is_wide_char(ch) ? 2 : 1; 295 prev_ch = ch; 296 } else 297 { 298 len = 1; 299 if (c == '\b') 300 /* XXX - Incorrect if several '\b' in a row. */ 301 width = (utf_mode && is_wide_char(prev_ch)) ? -2 : -1; 302 else if (!control_char(c)) 303 width = 1; 304 prev_ch = 0; 305 } 306 307 if (width == 2 && shift - shifted == 1) { 308 /* Should never happen when called by pshift_all(). */ 309 attr[to] = attr[from]; 310 /* 311 * Assume a wide_char will never be the first half of a 312 * combining_char pair, so reset prev_ch in case we're 313 * followed by a '\b'. 314 */ 315 prev_ch = linebuf[to++] = ' '; 316 from += len; 317 shifted++; 318 continue; 319 } 320 321 /* Adjust width for magic cookies. */ 322 prev_attr = (to > 0) ? attr[to-1] : AT_NORMAL; 323 next_attr = (from + len < curr) ? attr[from + len] : prev_attr; 324 if (!is_at_equiv(attr[from], prev_attr) && 325 !is_at_equiv(attr[from], next_attr)) 326 { 327 width += attr_swidth(attr[from]); 328 if (from + len < curr) 329 width += attr_ewidth(attr[from]); 330 if (is_at_equiv(prev_attr, next_attr)) 331 { 332 width += attr_ewidth(prev_attr); 333 if (from + len < curr) 334 width += attr_swidth(next_attr); 335 } 336 } 337 338 if (shift - shifted < width) 339 break; 340 from += len; 341 shifted += width; 342 if (shifted < 0) 343 shifted = 0; 344 } 345 while (from < curr) 346 { 347 linebuf[to] = linebuf[from]; 348 attr[to++] = attr[from++]; 349 } 350 curr = to; 351 column -= shifted; 352 cshift += shifted; 353 } 354 355 /* 356 * 357 */ 358 public void 359 pshift_all() 360 { 361 pshift(column); 362 } 363 364 /* 365 * Return the printing width of the start (enter) sequence 366 * for a given character attribute. 367 */ 368 static int 369 attr_swidth(a) 370 int a; 371 { 372 int w = 0; 373 374 a = apply_at_specials(a); 375 376 if (a & AT_UNDERLINE) 377 w += ul_s_width; 378 if (a & AT_BOLD) 379 w += bo_s_width; 380 if (a & AT_BLINK) 381 w += bl_s_width; 382 if (a & AT_STANDOUT) 383 w += so_s_width; 384 385 return w; 386 } 387 388 /* 389 * Return the printing width of the end (exit) sequence 390 * for a given character attribute. 391 */ 392 static int 393 attr_ewidth(a) 394 int a; 395 { 396 int w = 0; 397 398 a = apply_at_specials(a); 399 400 if (a & AT_UNDERLINE) 401 w += ul_e_width; 402 if (a & AT_BOLD) 403 w += bo_e_width; 404 if (a & AT_BLINK) 405 w += bl_e_width; 406 if (a & AT_STANDOUT) 407 w += so_e_width; 408 409 return w; 410 } 411 412 /* 413 * Return the printing width of a given character and attribute, 414 * if the character were added to the current position in the line buffer. 415 * Adding a character with a given attribute may cause an enter or exit 416 * attribute sequence to be inserted, so this must be taken into account. 417 */ 418 static int 419 pwidth(ch, a, prev_ch) 420 LWCHAR ch; 421 int a; 422 LWCHAR prev_ch; 423 { 424 int w; 425 426 if (ch == '\b') 427 /* 428 * Backspace moves backwards one or two positions. 429 * XXX - Incorrect if several '\b' in a row. 430 */ 431 return (utf_mode && is_wide_char(prev_ch)) ? -2 : -1; 432 433 if (!utf_mode || is_ascii_char(ch)) 434 { 435 if (control_char((char)ch)) 436 { 437 /* 438 * Control characters do unpredictable things, 439 * so we don't even try to guess; say it doesn't move. 440 * This can only happen if the -r flag is in effect. 441 */ 442 return (0); 443 } 444 } else 445 { 446 if (is_composing_char(ch) || is_combining_char(prev_ch, ch)) 447 { 448 /* 449 * Composing and combining chars take up no space. 450 * 451 * Some terminals, upon failure to compose a 452 * composing character with the character(s) that 453 * precede(s) it will actually take up one column 454 * for the composing character; there isn't much 455 * we could do short of testing the (complex) 456 * composition process ourselves and printing 457 * a binary representation when it fails. 458 */ 459 return (0); 460 } 461 } 462 463 /* 464 * Other characters take one or two columns, 465 * plus the width of any attribute enter/exit sequence. 466 */ 467 w = 1; 468 if (is_wide_char(ch)) 469 w++; 470 if (curr > 0 && !is_at_equiv(attr[curr-1], a)) 471 w += attr_ewidth(attr[curr-1]); 472 if ((apply_at_specials(a) != AT_NORMAL) && 473 (curr == 0 || !is_at_equiv(attr[curr-1], a))) 474 w += attr_swidth(a); 475 return (w); 476 } 477 478 /* 479 * Delete to the previous base character in the line buffer. 480 * Return 1 if one is found. 481 */ 482 static int 483 backc() 484 { 485 LWCHAR prev_ch; 486 char *p = linebuf + curr; 487 LWCHAR ch = step_char(&p, -1, linebuf + lmargin); 488 int width; 489 490 /* This assumes that there is no '\b' in linebuf. */ 491 while ( curr > lmargin 492 && column > lmargin 493 && (!(attr[curr - 1] & (AT_ANSI|AT_BINARY)))) 494 { 495 curr = p - linebuf; 496 prev_ch = step_char(&p, -1, linebuf + lmargin); 497 width = pwidth(ch, attr[curr], prev_ch); 498 column -= width; 499 if (width > 0) 500 return 1; 501 ch = prev_ch; 502 } 503 504 return 0; 505 } 506 507 /* 508 * Are we currently within a recognized ANSI escape sequence? 509 */ 510 static int 511 in_ansi_esc_seq() 512 { 513 char *p; 514 515 /* 516 * Search backwards for either an ESC (which means we ARE in a seq); 517 * or an end char (which means we're NOT in a seq). 518 */ 519 for (p = &linebuf[curr]; p > linebuf; ) 520 { 521 LWCHAR ch = step_char(&p, -1, linebuf); 522 if (IS_CSI_START(ch)) 523 return (1); 524 if (!is_ansi_middle(ch)) 525 return (0); 526 } 527 return (0); 528 } 529 530 /* 531 * Is a character the end of an ANSI escape sequence? 532 */ 533 public int 534 is_ansi_end(ch) 535 LWCHAR ch; 536 { 537 if (!is_ascii_char(ch)) 538 return (0); 539 return (strchr(end_ansi_chars, (char) ch) != NULL); 540 } 541 542 /* 543 * 544 */ 545 public int 546 is_ansi_middle(ch) 547 LWCHAR ch; 548 { 549 if (!is_ascii_char(ch)) 550 return (0); 551 if (is_ansi_end(ch)) 552 return (0); 553 return (strchr(mid_ansi_chars, (char) ch) != NULL); 554 } 555 556 /* 557 * Append a character and attribute to the line buffer. 558 */ 559 #define STORE_CHAR(ch,a,rep,pos) \ 560 do { \ 561 if (store_char((ch),(a),(rep),(pos))) return (1); \ 562 } while (0) 563 564 static int 565 store_char(ch, a, rep, pos) 566 LWCHAR ch; 567 int a; 568 char *rep; 569 POSITION pos; 570 { 571 int w; 572 int replen; 573 char cs; 574 575 w = (a & (AT_UNDERLINE|AT_BOLD)); /* Pre-use w. */ 576 if (w != AT_NORMAL) 577 last_overstrike = w; 578 579 #if HILITE_SEARCH 580 { 581 int matches; 582 if (is_hilited(pos, pos+1, 0, &matches)) 583 { 584 /* 585 * This character should be highlighted. 586 * Override the attribute passed in. 587 */ 588 if (a != AT_ANSI) 589 a |= AT_HILITE; 590 } 591 } 592 #endif 593 594 if (ctldisp == OPT_ONPLUS && in_ansi_esc_seq()) 595 { 596 if (!is_ansi_end(ch) && !is_ansi_middle(ch)) { 597 /* Remove whole unrecognized sequence. */ 598 char *p = &linebuf[curr]; 599 LWCHAR bch; 600 do { 601 bch = step_char(&p, -1, linebuf); 602 } while (p > linebuf && !IS_CSI_START(bch)); 603 curr = p - linebuf; 604 return 0; 605 } 606 a = AT_ANSI; /* Will force re-AT_'ing around it. */ 607 w = 0; 608 } 609 else if (ctldisp == OPT_ONPLUS && IS_CSI_START(ch)) 610 { 611 a = AT_ANSI; /* Will force re-AT_'ing around it. */ 612 w = 0; 613 } 614 else 615 { 616 char *p = &linebuf[curr]; 617 LWCHAR prev_ch = step_char(&p, -1, linebuf); 618 w = pwidth(ch, a, prev_ch); 619 } 620 621 if (ctldisp != OPT_ON && column + w + attr_ewidth(a) > sc_width) 622 /* 623 * Won't fit on screen. 624 */ 625 return (1); 626 627 if (rep == NULL) 628 { 629 cs = (char) ch; 630 rep = &cs; 631 replen = 1; 632 } else 633 { 634 replen = utf_len(rep[0]); 635 } 636 if (curr + replen >= size_linebuf-6) 637 { 638 /* 639 * Won't fit in line buffer. 640 * Try to expand it. 641 */ 642 if (expand_linebuf()) 643 return (1); 644 } 645 646 while (replen-- > 0) 647 { 648 linebuf[curr] = *rep++; 649 attr[curr] = a; 650 curr++; 651 } 652 column += w; 653 return (0); 654 } 655 656 /* 657 * Append a tab to the line buffer. 658 * Store spaces to represent the tab. 659 */ 660 #define STORE_TAB(a,pos) \ 661 do { if (store_tab((a),(pos))) return (1); } while (0) 662 663 static int 664 store_tab(attr, pos) 665 int attr; 666 POSITION pos; 667 { 668 int to_tab = column + cshift - lmargin; 669 int i; 670 671 if (ntabstops < 2 || to_tab >= tabstops[ntabstops-1]) 672 to_tab = tabdefault - 673 ((to_tab - tabstops[ntabstops-1]) % tabdefault); 674 else 675 { 676 for (i = ntabstops - 2; i >= 0; i--) 677 if (to_tab >= tabstops[i]) 678 break; 679 to_tab = tabstops[i+1] - to_tab; 680 } 681 682 if (column + to_tab - 1 + pwidth(' ', attr, 0) + attr_ewidth(attr) > sc_width) 683 return 1; 684 685 do { 686 STORE_CHAR(' ', attr, " ", pos); 687 } while (--to_tab > 0); 688 return 0; 689 } 690 691 #define STORE_PRCHAR(c, pos) \ 692 do { if (store_prchar((c), (pos))) return 1; } while (0) 693 694 static int 695 store_prchar(c, pos) 696 char c; 697 POSITION pos; 698 { 699 char *s; 700 701 /* 702 * Convert to printable representation. 703 */ 704 s = prchar(c); 705 706 /* 707 * Make sure we can get the entire representation 708 * of the character on this line. 709 */ 710 if (column + (int) strlen(s) - 1 + 711 pwidth(' ', binattr, 0) + attr_ewidth(binattr) > sc_width) 712 return 1; 713 714 for ( ; *s != 0; s++) 715 STORE_CHAR(*s, AT_BINARY, NULL, pos); 716 717 return 0; 718 } 719 720 static int 721 flush_mbc_buf(pos) 722 POSITION pos; 723 { 724 int i; 725 726 for (i = 0; i < mbc_buf_index; i++) 727 if (store_prchar(mbc_buf[i], pos)) 728 return mbc_buf_index - i; 729 730 return 0; 731 } 732 733 /* 734 * Append a character to the line buffer. 735 * Expand tabs into spaces, handle underlining, boldfacing, etc. 736 * Returns 0 if ok, 1 if couldn't fit in buffer. 737 */ 738 public int 739 pappend(c, pos) 740 char c; 741 POSITION pos; 742 { 743 int r; 744 745 if (pendc) 746 { 747 if (do_append(pendc, NULL, pendpos)) 748 /* 749 * Oops. We've probably lost the char which 750 * was in pendc, since caller won't back up. 751 */ 752 return (1); 753 pendc = '\0'; 754 } 755 756 if (c == '\r' && bs_mode == BS_SPECIAL) 757 { 758 if (mbc_buf_len > 0) /* utf_mode must be on. */ 759 { 760 /* Flush incomplete (truncated) sequence. */ 761 r = flush_mbc_buf(mbc_pos); 762 mbc_buf_index = r + 1; 763 mbc_buf_len = 0; 764 if (r) 765 return (mbc_buf_index); 766 } 767 768 /* 769 * Don't put the CR into the buffer until we see 770 * the next char. If the next char is a newline, 771 * discard the CR. 772 */ 773 pendc = c; 774 pendpos = pos; 775 return (0); 776 } 777 778 if (!utf_mode) 779 { 780 r = do_append((LWCHAR) c, NULL, pos); 781 } else 782 { 783 /* Perform strict validation in all possible cases. */ 784 if (mbc_buf_len == 0) 785 { 786 retry: 787 mbc_buf_index = 1; 788 *mbc_buf = c; 789 if (IS_ASCII_OCTET(c)) 790 r = do_append((LWCHAR) c, NULL, pos); 791 else if (IS_UTF8_LEAD(c)) 792 { 793 mbc_buf_len = utf_len(c); 794 mbc_pos = pos; 795 return (0); 796 } else 797 /* UTF8_INVALID or stray UTF8_TRAIL */ 798 r = flush_mbc_buf(pos); 799 } else if (IS_UTF8_TRAIL(c)) 800 { 801 mbc_buf[mbc_buf_index++] = c; 802 if (mbc_buf_index < mbc_buf_len) 803 return (0); 804 if (is_utf8_well_formed(mbc_buf)) 805 r = do_append(get_wchar(mbc_buf), mbc_buf, mbc_pos); 806 else 807 /* Complete, but not shortest form, sequence. */ 808 mbc_buf_index = r = flush_mbc_buf(mbc_pos); 809 mbc_buf_len = 0; 810 } else 811 { 812 /* Flush incomplete (truncated) sequence. */ 813 r = flush_mbc_buf(mbc_pos); 814 mbc_buf_index = r + 1; 815 mbc_buf_len = 0; 816 /* Handle new char. */ 817 if (!r) 818 goto retry; 819 } 820 } 821 822 /* 823 * If we need to shift the line, do it. 824 * But wait until we get to at least the middle of the screen, 825 * so shifting it doesn't affect the chars we're currently 826 * pappending. (Bold & underline can get messed up otherwise.) 827 */ 828 if (cshift < hshift && column > sc_width / 2) 829 { 830 linebuf[curr] = '\0'; 831 pshift(hshift - cshift); 832 } 833 if (r) 834 { 835 /* How many chars should caller back up? */ 836 r = (!utf_mode) ? 1 : mbc_buf_index; 837 } 838 return (r); 839 } 840 841 static int 842 do_append(ch, rep, pos) 843 LWCHAR ch; 844 char *rep; 845 POSITION pos; 846 { 847 register int a; 848 LWCHAR prev_ch; 849 850 a = AT_NORMAL; 851 852 if (ch == '\b') 853 { 854 if (bs_mode == BS_CONTROL) 855 goto do_control_char; 856 857 /* 858 * A better test is needed here so we don't 859 * backspace over part of the printed 860 * representation of a binary character. 861 */ 862 if ( curr <= lmargin 863 || column <= lmargin 864 || (attr[curr - 1] & (AT_ANSI|AT_BINARY))) 865 STORE_PRCHAR('\b', pos); 866 else if (bs_mode == BS_NORMAL) 867 STORE_CHAR(ch, AT_NORMAL, NULL, pos); 868 else if (bs_mode == BS_SPECIAL) 869 overstrike = backc(); 870 871 return 0; 872 } 873 874 if (overstrike > 0) 875 { 876 /* 877 * Overstrike the character at the current position 878 * in the line buffer. This will cause either 879 * underline (if a "_" is overstruck), 880 * bold (if an identical character is overstruck), 881 * or just deletion of the character in the buffer. 882 */ 883 overstrike = utf_mode ? -1 : 0; 884 /* To be correct, this must be a base character. */ 885 prev_ch = get_wchar(linebuf + curr); 886 a = attr[curr]; 887 if (ch == prev_ch) 888 { 889 /* 890 * Overstriking a char with itself means make it bold. 891 * But overstriking an underscore with itself is 892 * ambiguous. It could mean make it bold, or 893 * it could mean make it underlined. 894 * Use the previous overstrike to resolve it. 895 */ 896 if (ch == '_') 897 { 898 if ((a & (AT_BOLD|AT_UNDERLINE)) != AT_NORMAL) 899 a |= (AT_BOLD|AT_UNDERLINE); 900 else if (last_overstrike != AT_NORMAL) 901 a |= last_overstrike; 902 else 903 a |= AT_BOLD; 904 } else 905 a |= AT_BOLD; 906 } else if (ch == '_') 907 { 908 a |= AT_UNDERLINE; 909 ch = prev_ch; 910 rep = linebuf + curr; 911 } else if (prev_ch == '_') 912 { 913 a |= AT_UNDERLINE; 914 } 915 /* Else we replace prev_ch, but we keep its attributes. */ 916 } else if (overstrike < 0) 917 { 918 if ( is_composing_char(ch) 919 || is_combining_char(get_wchar(linebuf + curr), ch)) 920 /* Continuation of the same overstrike. */ 921 a = last_overstrike; 922 else 923 overstrike = 0; 924 } 925 926 if (ch == '\t') 927 { 928 /* 929 * Expand a tab into spaces. 930 */ 931 switch (bs_mode) 932 { 933 case BS_CONTROL: 934 goto do_control_char; 935 case BS_NORMAL: 936 case BS_SPECIAL: 937 STORE_TAB(a, pos); 938 break; 939 } 940 } else if ((!utf_mode || is_ascii_char(ch)) && control_char((char)ch)) 941 { 942 do_control_char: 943 if (ctldisp == OPT_ON || (ctldisp == OPT_ONPLUS && IS_CSI_START(ch))) 944 { 945 /* 946 * Output as a normal character. 947 */ 948 STORE_CHAR(ch, AT_NORMAL, rep, pos); 949 } else 950 { 951 STORE_PRCHAR((char) ch, pos); 952 } 953 } else if (utf_mode && ctldisp != OPT_ON && is_ubin_char(ch)) 954 { 955 char *s; 956 957 s = prutfchar(ch); 958 959 if (column + (int) strlen(s) - 1 + 960 pwidth(' ', binattr, 0) + attr_ewidth(binattr) > sc_width) 961 return (1); 962 963 for ( ; *s != 0; s++) 964 STORE_CHAR(*s, AT_BINARY, NULL, pos); 965 } else 966 { 967 STORE_CHAR(ch, a, rep, pos); 968 } 969 return (0); 970 } 971 972 /* 973 * 974 */ 975 public int 976 pflushmbc() 977 { 978 int r = 0; 979 980 if (mbc_buf_len > 0) 981 { 982 /* Flush incomplete (truncated) sequence. */ 983 r = flush_mbc_buf(mbc_pos); 984 mbc_buf_len = 0; 985 } 986 return r; 987 } 988 989 /* 990 * Terminate the line in the line buffer. 991 */ 992 public void 993 pdone(endline, forw) 994 int endline; 995 int forw; 996 { 997 (void) pflushmbc(); 998 999 if (pendc && (pendc != '\r' || !endline)) 1000 /* 1001 * If we had a pending character, put it in the buffer. 1002 * But discard a pending CR if we are at end of line 1003 * (that is, discard the CR in a CR/LF sequence). 1004 */ 1005 (void) do_append(pendc, NULL, pendpos); 1006 1007 /* 1008 * Make sure we've shifted the line, if we need to. 1009 */ 1010 if (cshift < hshift) 1011 pshift(hshift - cshift); 1012 1013 if (ctldisp == OPT_ONPLUS && is_ansi_end('m')) 1014 { 1015 /* Switch to normal attribute at end of line. */ 1016 char *p = "\033[m"; 1017 for ( ; *p != '\0'; p++) 1018 { 1019 linebuf[curr] = *p; 1020 attr[curr++] = AT_ANSI; 1021 } 1022 } 1023 1024 /* 1025 * Add a newline if necessary, 1026 * and append a '\0' to the end of the line. 1027 * We output a newline if we're not at the right edge of the screen, 1028 * or if the terminal doesn't auto wrap, 1029 * or if this is really the end of the line AND the terminal ignores 1030 * a newline at the right edge. 1031 * (In the last case we don't want to output a newline if the terminal 1032 * doesn't ignore it since that would produce an extra blank line. 1033 * But we do want to output a newline if the terminal ignores it in case 1034 * the next line is blank. In that case the single newline output for 1035 * that blank line would be ignored!) 1036 */ 1037 if (column < sc_width || !auto_wrap || (endline && ignaw) || ctldisp == OPT_ON) 1038 { 1039 linebuf[curr] = '\n'; 1040 attr[curr] = AT_NORMAL; 1041 curr++; 1042 } 1043 else if (ignaw && column >= sc_width && forw) 1044 { 1045 /* 1046 * Terminals with "ignaw" don't wrap until they *really* need 1047 * to, i.e. when the character *after* the last one to fit on a 1048 * line is output. But they are too hard to deal with when they 1049 * get in the state where a full screen width of characters 1050 * have been output but the cursor is sitting on the right edge 1051 * instead of at the start of the next line. 1052 * So we nudge them into wrapping by outputting a space 1053 * character plus a backspace. But do this only if moving 1054 * forward; if we're moving backward and drawing this line at 1055 * the top of the screen, the space would overwrite the first 1056 * char on the next line. We don't need to do this "nudge" 1057 * at the top of the screen anyway. 1058 */ 1059 linebuf[curr] = ' '; 1060 attr[curr++] = AT_NORMAL; 1061 linebuf[curr] = '\b'; 1062 attr[curr++] = AT_NORMAL; 1063 } 1064 linebuf[curr] = '\0'; 1065 attr[curr] = AT_NORMAL; 1066 } 1067 1068 /* 1069 * 1070 */ 1071 public void 1072 set_status_col(c) 1073 char c; 1074 { 1075 linebuf[0] = c; 1076 attr[0] = AT_NORMAL|AT_HILITE; 1077 } 1078 1079 /* 1080 * Get a character from the current line. 1081 * Return the character as the function return value, 1082 * and the character attribute in *ap. 1083 */ 1084 public int 1085 gline(i, ap) 1086 register int i; 1087 register int *ap; 1088 { 1089 if (is_null_line) 1090 { 1091 /* 1092 * If there is no current line, we pretend the line is 1093 * either "~" or "", depending on the "twiddle" flag. 1094 */ 1095 if (twiddle) 1096 { 1097 if (i == 0) 1098 { 1099 *ap = AT_BOLD; 1100 return '~'; 1101 } 1102 --i; 1103 } 1104 /* Make sure we're back to AT_NORMAL before the '\n'. */ 1105 *ap = AT_NORMAL; 1106 return i ? '\0' : '\n'; 1107 } 1108 1109 *ap = attr[i]; 1110 return (linebuf[i] & 0xFF); 1111 } 1112 1113 /* 1114 * Indicate that there is no current line. 1115 */ 1116 public void 1117 null_line() 1118 { 1119 is_null_line = 1; 1120 cshift = 0; 1121 } 1122 1123 /* 1124 * Analogous to forw_line(), but deals with "raw lines": 1125 * lines which are not split for screen width. 1126 * {{ This is supposed to be more efficient than forw_line(). }} 1127 */ 1128 public POSITION 1129 forw_raw_line(curr_pos, linep, line_lenp) 1130 POSITION curr_pos; 1131 char **linep; 1132 int *line_lenp; 1133 { 1134 register int n; 1135 register int c; 1136 POSITION new_pos; 1137 1138 if (curr_pos == NULL_POSITION || ch_seek(curr_pos) || 1139 (c = ch_forw_get()) == EOI) 1140 return (NULL_POSITION); 1141 1142 n = 0; 1143 for (;;) 1144 { 1145 if (c == '\n' || c == EOI || ABORT_SIGS()) 1146 { 1147 new_pos = ch_tell(); 1148 break; 1149 } 1150 if (n >= size_linebuf-1) 1151 { 1152 if (expand_linebuf()) 1153 { 1154 /* 1155 * Overflowed the input buffer. 1156 * Pretend the line ended here. 1157 */ 1158 new_pos = ch_tell() - 1; 1159 break; 1160 } 1161 } 1162 linebuf[n++] = c; 1163 c = ch_forw_get(); 1164 } 1165 linebuf[n] = '\0'; 1166 if (linep != NULL) 1167 *linep = linebuf; 1168 if (line_lenp != NULL) 1169 *line_lenp = n; 1170 return (new_pos); 1171 } 1172 1173 /* 1174 * Analogous to back_line(), but deals with "raw lines". 1175 * {{ This is supposed to be more efficient than back_line(). }} 1176 */ 1177 public POSITION 1178 back_raw_line(curr_pos, linep, line_lenp) 1179 POSITION curr_pos; 1180 char **linep; 1181 int *line_lenp; 1182 { 1183 register int n; 1184 register int c; 1185 POSITION new_pos; 1186 1187 if (curr_pos == NULL_POSITION || curr_pos <= ch_zero() || 1188 ch_seek(curr_pos-1)) 1189 return (NULL_POSITION); 1190 1191 n = size_linebuf; 1192 linebuf[--n] = '\0'; 1193 for (;;) 1194 { 1195 c = ch_back_get(); 1196 if (c == '\n' || ABORT_SIGS()) 1197 { 1198 /* 1199 * This is the newline ending the previous line. 1200 * We have hit the beginning of the line. 1201 */ 1202 new_pos = ch_tell() + 1; 1203 break; 1204 } 1205 if (c == EOI) 1206 { 1207 /* 1208 * We have hit the beginning of the file. 1209 * This must be the first line in the file. 1210 * This must, of course, be the beginning of the line. 1211 */ 1212 new_pos = ch_zero(); 1213 break; 1214 } 1215 if (n <= 0) 1216 { 1217 int old_size_linebuf = size_linebuf; 1218 char *fm; 1219 char *to; 1220 if (expand_linebuf()) 1221 { 1222 /* 1223 * Overflowed the input buffer. 1224 * Pretend the line ended here. 1225 */ 1226 new_pos = ch_tell() + 1; 1227 break; 1228 } 1229 /* 1230 * Shift the data to the end of the new linebuf. 1231 */ 1232 for (fm = linebuf + old_size_linebuf - 1, 1233 to = linebuf + size_linebuf - 1; 1234 fm >= linebuf; fm--, to--) 1235 *to = *fm; 1236 n = size_linebuf - old_size_linebuf; 1237 } 1238 linebuf[--n] = c; 1239 } 1240 if (linep != NULL) 1241 *linep = &linebuf[n]; 1242 if (line_lenp != NULL) 1243 *line_lenp = size_linebuf - 1 - n; 1244 return (new_pos); 1245 } 1246