usr.bin/col/col.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1990, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Michael Rendell of the Memorial University of Newfoundland.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifndef lint
  36 static const char copyright[] =
  37 "@(#) Copyright (c) 1990, 1993, 1994\n\
  38         The Regents of the University of California.  All rights reserved.\n";
  39 #endif
  40
  41 #if 0
  42 #ifndef lint
  43 static char sccsid[] = "@(#)col.c       8.5 (Berkeley) 5/4/95";
  44 #endif
  45 #endif
  46
  47 #include <sys/cdefs.h>
  48 __FBSDID("$FreeBSD$");
  49
  50 #include <sys/capsicum.h>
  51
  52 #include <capsicum_helpers.h>
  53 #include <err.h>
  54 #include <errno.h>
  55 #include <locale.h>
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <string.h>
  59 #include <termios.h>
  60 #include <unistd.h>
  61 #include <wchar.h>
  62 #include <wctype.h>
  63
  64 #define BS      '\b'            /* backspace */
  65 #define TAB     '\t'            /* tab */
  66 #define SPACE   ' '             /* space */
  67 #define NL      '\n'            /* newline */
  68 #define CR      '\r'            /* carriage return */
  69 #define ESC     '\033'          /* escape */
  70 #define SI      '\017'          /* shift in to normal character set */
  71 #define SO      '\016'          /* shift out to alternate character set */
  72 #define VT      '\013'          /* vertical tab (aka reverse line feed) */
  73 #define RLF     '7'             /* ESC-7 reverse line feed */
  74 #define RHLF    '8'             /* ESC-8 reverse half-line feed */
  75 #define FHLF    '9'             /* ESC-9 forward half-line feed */
  76
  77 /* build up at least this many lines before flushing them out */
  78 #define BUFFER_MARGIN           32
  79
  80 typedef char CSET;
  81
  82 typedef struct char_str {
  83 #define CS_NORMAL       1
  84 #define CS_ALTERNATE    2
  85         short           c_column;       /* column character is in */
  86         CSET            c_set;          /* character set (currently only 2) */
  87         wchar_t         c_char;         /* character in question */
  88         int             c_width;        /* character width */
  89 } CHAR;
  90
  91 typedef struct line_str LINE;
  92 struct line_str {
  93         CHAR    *l_line;                /* characters on the line */
  94         LINE    *l_prev;                /* previous line */
  95         LINE    *l_next;                /* next line */
  96         int     l_lsize;                /* allocated sizeof l_line */
  97         int     l_line_len;             /* strlen(l_line) */
  98         int     l_needs_sort;           /* set if chars went in out of order */
  99         int     l_max_col;              /* max column in the line */
 100 };
 101
 102 static void     addto_lineno(int *, int);
 103 static LINE     *alloc_line(void);
 104 static void     dowarn(int);
 105 static void     flush_line(LINE *);
 106 static void     flush_lines(int);
 107 static void     flush_blanks(void);
 108 static void     free_line(LINE *);
 109 static void     usage(void);
 110
 111 static CSET     last_set;               /* char_set of last char printed */
 112 static LINE     *lines;
 113 static int      compress_spaces;        /* if doing space -> tab conversion */
 114 static int      fine;                   /* if `fine' resolution (half lines) */
 115 static int      max_bufd_lines;         /* max # of half lines to keep in memory */
 116 static int      nblank_lines;           /* # blanks after last flushed line */
 117 static int      no_backspaces;          /* if not to output any backspaces */
 118 static int      pass_unknown_seqs;      /* pass unknown control sequences */
 119
 120 #define PUTC(ch) \
 121         do {                                    \
 122                 if (putwchar(ch) == WEOF)       \
 123                         errx(1, "write error"); \
 124         } while (0)
 125
 126 int
 127 main(int argc, char **argv)
 128 {
 129         wint_t ch;
 130         CHAR *c;
 131         CSET cur_set;                   /* current character set */
 132         LINE *l;                        /* current line */
 133         int extra_lines;                /* # of lines above first line */
 134         int cur_col;                    /* current column */
 135         int cur_line;                   /* line number of current position */
 136         int max_line;                   /* max value of cur_line */
 137         int this_line;                  /* line l points to */
 138         int nflushd_lines;              /* number of lines that were flushed */
 139         int adjust, opt, warned, width;
 140         const char *errstr;
 141
 142         (void)setlocale(LC_CTYPE, "");
 143
 144         if (caph_limit_stdio() == -1)
 145                 err(1, "unable to limit stdio");
 146
 147         if (caph_enter() < 0)
 148                 err(1, "unable to enter capability mode");
 149
 150         max_bufd_lines = 256;
 151         compress_spaces = 1;            /* compress spaces into tabs */
 152         while ((opt = getopt(argc, argv, "bfhl:px")) != -1)
 153                 switch (opt) {
 154                 case 'b':               /* do not output backspaces */
 155                         no_backspaces = 1;
 156                         break;
 157                 case 'f':               /* allow half forward line feeds */
 158                         fine = 1;
 159                         break;
 160                 case 'h':               /* compress spaces into tabs */
 161                         compress_spaces = 1;
 162                         break;
 163                 case 'l':               /* buffered line count */
 164                         max_bufd_lines = strtonum(optarg, 1,
 165                             (INT_MAX - BUFFER_MARGIN) / 2, &errstr) * 2;
 166                         if (errstr != NULL)
 167                                 errx(1, "bad -l argument, %s: %s", errstr,
 168                                         optarg);
 169                         break;
 170                 case 'p':               /* pass unknown control sequences */
 171                         pass_unknown_seqs = 1;
 172                         break;
 173                 case 'x':               /* do not compress spaces into tabs */
 174                         compress_spaces = 0;
 175                         break;
 176                 case '?':
 177                 default:
 178                         usage();
 179                 }
 180
 181         if (optind != argc)
 182                 usage();
 183
 184         adjust = cur_col = extra_lines = warned = 0;
 185         cur_line = max_line = nflushd_lines = this_line = 0;
 186         cur_set = last_set = CS_NORMAL;
 187         lines = l = alloc_line();
 188
 189         while ((ch = getwchar()) != WEOF) {
 190                 if (!iswgraph(ch)) {
 191                         switch (ch) {
 192                         case BS:                /* can't go back further */
 193                                 if (cur_col == 0)
 194                                         continue;
 195                                 --cur_col;
 196                                 continue;
 197                         case CR:
 198                                 cur_col = 0;
 199                                 continue;
 200                         case ESC:               /* just ignore EOF */
 201                                 switch(getwchar()) {
 202                                 /*
 203                                  * In the input stream, accept both the
 204                                  * XPG5 sequences ESC-digit and the
 205                                  * traditional BSD sequences ESC-ctrl.
 206                                  */
 207                                 case '\007':
 208                                         /* FALLTHROUGH */
 209                                 case RLF:
 210                                         addto_lineno(&cur_line, -2);
 211                                         break;
 212                                 case '\010':
 213                                         /* FALLTHROUGH */
 214                                 case RHLF:
 215                                         addto_lineno(&cur_line, -1);
 216                                         break;
 217                                 case '\011':
 218                                         /* FALLTHROUGH */
 219                                 case FHLF:
 220                                         addto_lineno(&cur_line, 1);
 221                                         if (cur_line > max_line)
 222                                                 max_line = cur_line;
 223                                 }
 224                                 continue;
 225                         case NL:
 226                                 addto_lineno(&cur_line, 2);
 227                                 if (cur_line > max_line)
 228                                         max_line = cur_line;
 229                                 cur_col = 0;
 230                                 continue;
 231                         case SPACE:
 232                                 ++cur_col;
 233                                 continue;
 234                         case SI:
 235                                 cur_set = CS_NORMAL;
 236                                 continue;
 237                         case SO:
 238                                 cur_set = CS_ALTERNATE;
 239                                 continue;
 240                         case TAB:               /* adjust column */
 241                                 cur_col |= 7;
 242                                 ++cur_col;
 243                                 continue;
 244                         case VT:
 245                                 addto_lineno(&cur_line, -2);
 246                                 continue;
 247                         }
 248                         if (iswspace(ch)) {
 249                                 if ((width = wcwidth(ch)) > 0)
 250                                         cur_col += width;
 251                                 continue;
 252                         }
 253                         if (!pass_unknown_seqs)
 254                                 continue;
 255                 }
 256
 257                 /* Must stuff ch in a line - are we at the right one? */
 258                 if (cur_line + adjust != this_line) {
 259                         LINE *lnew;
 260
 261                         /* round up to next line */
 262                         adjust = !fine && (cur_line & 1);
 263
 264                         if (cur_line + adjust < this_line) {
 265                                 while (cur_line + adjust < this_line &&
 266                                     l->l_prev != NULL) {
 267                                         l = l->l_prev;
 268                                         this_line--;
 269                                 }
 270                                 if (cur_line + adjust < this_line) {
 271                                         if (nflushd_lines == 0) {
 272                                                 /*
 273                                                  * Allow backup past first
 274                                                  * line if nothing has been
 275                                                  * flushed yet.
 276                                                  */
 277                                                 while (cur_line + adjust
 278                                                     < this_line) {
 279                                                         lnew = alloc_line();
 280                                                         l->l_prev = lnew;
 281                                                         lnew->l_next = l;
 282                                                         l = lines = lnew;
 283                                                         extra_lines++;
 284                                                         this_line--;
 285                                                 }
 286                                         } else {
 287                                                 if (!warned++)
 288                                                         dowarn(cur_line);
 289                                                 cur_line = this_line - adjust;
 290                                         }
 291                                 }
 292                         } else {
 293                                 /* may need to allocate here */
 294                                 while (cur_line + adjust > this_line) {
 295                                         if (l->l_next == NULL) {
 296                                                 l->l_next = alloc_line();
 297                                                 l->l_next->l_prev = l;
 298                                         }
 299                                         l = l->l_next;
 300                                         this_line++;
 301                                 }
 302                         }
 303                         if (this_line > nflushd_lines &&
 304                             this_line - nflushd_lines >=
 305                             max_bufd_lines + BUFFER_MARGIN) {
 306                                 if (extra_lines) {
 307                                         flush_lines(extra_lines);
 308                                         extra_lines = 0;
 309                                 }
 310                                 flush_lines(this_line - nflushd_lines -
 311                                     max_bufd_lines);
 312                                 nflushd_lines = this_line - max_bufd_lines;
 313                         }
 314                 }
 315                 /* grow line's buffer? */
 316                 if (l->l_line_len + 1 >= l->l_lsize) {
 317                         int need;
 318
 319                         need = l->l_lsize ? l->l_lsize * 2 : 90;
 320                         if ((l->l_line = realloc(l->l_line,
 321                             (unsigned)need * sizeof(CHAR))) == NULL)
 322                                 err(1, NULL);
 323                         l->l_lsize = need;
 324                 }
 325                 c = &l->l_line[l->l_line_len++];
 326                 c->c_char = ch;
 327                 c->c_set = cur_set;
 328                 c->c_column = cur_col;
 329                 c->c_width = wcwidth(ch);
 330                 /*
 331                  * If things are put in out of order, they will need sorting
 332                  * when it is flushed.
 333                  */
 334                 if (cur_col < l->l_max_col)
 335                         l->l_needs_sort = 1;
 336                 else
 337                         l->l_max_col = cur_col;
 338                 if (c->c_width > 0)
 339                         cur_col += c->c_width;
 340         }
 341         if (ferror(stdin))
 342                 err(1, NULL);
 343         if (extra_lines) {
 344                 /*
 345                  * Extra lines only exist if no lines have been flushed
 346                  * yet. This means that 'lines' must point to line zero
 347                  * after we flush the extra lines.
 348                  */
 349                 flush_lines(extra_lines);
 350                 l = lines;
 351                 this_line = 0;
 352         }
 353
 354         /* goto the last line that had a character on it */
 355         for (; l->l_next; l = l->l_next)
 356                 this_line++;
 357         flush_lines(this_line - nflushd_lines + 1);
 358
 359         /* make sure we leave things in a sane state */
 360         if (last_set != CS_NORMAL)
 361                 PUTC(SI);
 362
 363         /* flush out the last few blank lines */
 364         if (max_line >= this_line)
 365                 nblank_lines = max_line - this_line + (max_line & 1);
 366         if (nblank_lines == 0)
 367                 /* end with a newline even if the source doesn't */
 368                 nblank_lines = 2;
 369         flush_blanks();
 370         exit(0);
 371 }
 372
 373 /*
 374  * Prints the first 'nflush' lines. Printed lines are freed.
 375  * After this function returns, 'lines' points to the first
 376  * of the remaining lines, and 'nblank_lines' will have the
 377  * number of half line feeds between the final flushed line
 378  * and the first remaining line.
 379  */
 380 static void
 381 flush_lines(int nflush)
 382 {
 383         LINE *l;
 384
 385         while (--nflush >= 0) {
 386                 l = lines;
 387                 lines = l->l_next;
 388                 if (l->l_line) {
 389                         flush_blanks();
 390                         flush_line(l);
 391                         free(l->l_line);
 392                 }
 393                 if (l->l_next)
 394                         nblank_lines++;
 395                 free_line(l);
 396         }
 397         if (lines)
 398                 lines->l_prev = NULL;
 399 }
 400
 401 /*
 402  * Print a number of newline/half newlines.
 403  * nblank_lines is the number of half line feeds.
 404  */
 405 static void
 406 flush_blanks(void)
 407 {
 408         int half, i, nb;
 409
 410         half = 0;
 411         nb = nblank_lines;
 412         if (nb & 1) {
 413                 if (fine)
 414                         half = 1;
 415                 else
 416                         nb++;
 417         }
 418         nb /= 2;
 419         for (i = nb; --i >= 0;)
 420                 PUTC('\n');
 421         if (half) {
 422                 PUTC(ESC);
 423                 PUTC(FHLF);
 424                 if (!nb)
 425                         PUTC('\r');
 426         }
 427         nblank_lines = 0;
 428 }
 429
 430 /*
 431  * Write a line to stdout taking care of space to tab conversion (-h flag)
 432  * and character set shifts.
 433  */
 434 static void
 435 flush_line(LINE *l)
 436 {
 437         CHAR *c, *endc;
 438         int i, j, nchars, last_col, save, this_col, tot;
 439
 440         last_col = 0;
 441         nchars = l->l_line_len;
 442
 443         if (l->l_needs_sort) {
 444                 static CHAR *sorted;
 445                 static int count_size, *count, sorted_size;
 446
 447                 /*
 448                  * Do an O(n) sort on l->l_line by column being careful to
 449                  * preserve the order of characters in the same column.
 450                  */
 451                 if (l->l_lsize > sorted_size) {
 452                         sorted_size = l->l_lsize;
 453                         if ((sorted = realloc(sorted,
 454                             (unsigned)sizeof(CHAR) * sorted_size)) == NULL)
 455                                 err(1, NULL);
 456                 }
 457                 if (l->l_max_col >= count_size) {
 458                         count_size = l->l_max_col + 1;
 459                         if ((count = realloc(count,
 460                             (unsigned)sizeof(int) * count_size)) == NULL)
 461                                 err(1, NULL);
 462                 }
 463                 memset(count, 0, sizeof(int) * l->l_max_col + 1);
 464                 for (i = nchars, c = l->l_line; --i >= 0; c++)
 465                         count[c->c_column]++;
 466
 467                 /*
 468                  * calculate running total (shifted down by 1) to use as
 469                  * indices into new line.
 470                  */
 471                 for (tot = 0, i = 0; i <= l->l_max_col; i++) {
 472                         save = count[i];
 473                         count[i] = tot;
 474                         tot += save;
 475                 }
 476
 477                 for (i = nchars, c = l->l_line; --i >= 0; c++)
 478                         sorted[count[c->c_column]++] = *c;
 479                 c = sorted;
 480         } else
 481                 c = l->l_line;
 482         while (nchars > 0) {
 483                 this_col = c->c_column;
 484                 endc = c;
 485                 do {
 486                         ++endc;
 487                 } while (--nchars > 0 && this_col == endc->c_column);
 488
 489                 /* if -b only print last character */
 490                 if (no_backspaces) {
 491                         c = endc - 1;
 492                         if (nchars > 0 &&
 493                             this_col + c->c_width > endc->c_column)
 494                                 continue;
 495                 }
 496
 497                 if (this_col > last_col) {
 498                         int nspace = this_col - last_col;
 499
 500                         if (compress_spaces && nspace > 1) {
 501                                 while (1) {
 502                                         int tab_col, tab_size;
 503
 504                                         tab_col = (last_col + 8) & ~7;
 505                                         if (tab_col > this_col)
 506                                                 break;
 507                                         tab_size = tab_col - last_col;
 508                                         if (tab_size == 1)
 509                                                 PUTC(' ');
 510                                         else
 511                                                 PUTC('\t');
 512                                         nspace -= tab_size;
 513                                         last_col = tab_col;
 514                                 }
 515                         }
 516                         while (--nspace >= 0)
 517                                 PUTC(' ');
 518                         last_col = this_col;
 519                 }
 520
 521                 for (;;) {
 522                         if (c->c_set != last_set) {
 523                                 switch (c->c_set) {
 524                                 case CS_NORMAL:
 525                                         PUTC(SI);
 526                                         break;
 527                                 case CS_ALTERNATE:
 528                                         PUTC(SO);
 529                                 }
 530                                 last_set = c->c_set;
 531                         }
 532                         PUTC(c->c_char);
 533                         if ((c + 1) < endc)
 534                                 for (j = 0; j < c->c_width; j++)
 535                                         PUTC('\b');
 536                         if (++c >= endc)
 537                                 break;
 538                 }
 539                 last_col += (c - 1)->c_width;
 540         }
 541 }
 542
 543 /*
 544  * Increment or decrement a line number, checking for overflow.
 545  * Stop one below INT_MAX such that the adjust variable is safe.
 546  */
 547 void
 548 addto_lineno(int *lno, int offset)
 549 {
 550         if (offset > 0) {
 551                 if (*lno >= INT_MAX - offset)
 552                         errx(1, "too many lines");
 553         } else {
 554                 if (*lno < INT_MIN - offset)
 555                         errx(1, "too many reverse line feeds");
 556         }
 557         *lno += offset;
 558 }
 559
 560 #define NALLOC 64
 561
 562 static LINE *line_freelist;
 563
 564 static LINE *
 565 alloc_line(void)
 566 {
 567         LINE *l;
 568         int i;
 569
 570         if (!line_freelist) {
 571                 if ((l = realloc(NULL, sizeof(LINE) * NALLOC)) == NULL)
 572                         err(1, NULL);
 573                 line_freelist = l;
 574                 for (i = 1; i < NALLOC; i++, l++)
 575                         l->l_next = l + 1;
 576                 l->l_next = NULL;
 577         }
 578         l = line_freelist;
 579         line_freelist = l->l_next;
 580
 581         memset(l, 0, sizeof(LINE));
 582         return (l);
 583 }
 584
 585 static void
 586 free_line(LINE *l)
 587 {
 588
 589         l->l_next = line_freelist;
 590         line_freelist = l;
 591 }
 592
 593 static void
 594 usage(void)
 595 {
 596
 597         (void)fprintf(stderr, "usage: col [-bfhpx] [-l nline]\n");
 598         exit(1);
 599 }
 600
 601 static void
 602 dowarn(int line)
 603 {
 604
 605         warnx("warning: can't back up %s",
 606                 line < 0 ? "past first line" : "-- line already flushed");
 607 }