usr.bin/col/col.c

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