html.c

   1 /*      $Id: html.c,v 1.171 2014/09/27 10:56:18 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2011, 2012, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #include "config.h"
  19
  20 #include <sys/types.h>
  21
  22 #include <assert.h>
  23 #include <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdio.h>
  26 #include <stdint.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 #include "mandoc.h"
  32 #include "mandoc_aux.h"
  33 #include "libmandoc.h"
  34 #include "out.h"
  35 #include "html.h"
  36 #include "main.h"
  37
  38 struct  htmldata {
  39         const char       *name;
  40         int               flags;
  41 #define HTML_CLRLINE     (1 << 0)
  42 #define HTML_NOSTACK     (1 << 1)
  43 #define HTML_AUTOCLOSE   (1 << 2) /* Tag has auto-closure. */
  44 };
  45
  46 static  const struct htmldata htmltags[TAG_MAX] = {
  47         {"html",        HTML_CLRLINE}, /* TAG_HTML */
  48         {"head",        HTML_CLRLINE}, /* TAG_HEAD */
  49         {"body",        HTML_CLRLINE}, /* TAG_BODY */
  50         {"meta",        HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_META */
  51         {"title",       HTML_CLRLINE}, /* TAG_TITLE */
  52         {"div",         HTML_CLRLINE}, /* TAG_DIV */
  53         {"h1",          0}, /* TAG_H1 */
  54         {"h2",          0}, /* TAG_H2 */
  55         {"span",        0}, /* TAG_SPAN */
  56         {"link",        HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_LINK */
  57         {"br",          HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_BR */
  58         {"a",           0}, /* TAG_A */
  59         {"table",       HTML_CLRLINE}, /* TAG_TABLE */
  60         {"tbody",       HTML_CLRLINE}, /* TAG_TBODY */
  61         {"col",         HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_COL */
  62         {"tr",          HTML_CLRLINE}, /* TAG_TR */
  63         {"td",          HTML_CLRLINE}, /* TAG_TD */
  64         {"li",          HTML_CLRLINE}, /* TAG_LI */
  65         {"ul",          HTML_CLRLINE}, /* TAG_UL */
  66         {"ol",          HTML_CLRLINE}, /* TAG_OL */
  67         {"dl",          HTML_CLRLINE}, /* TAG_DL */
  68         {"dt",          HTML_CLRLINE}, /* TAG_DT */
  69         {"dd",          HTML_CLRLINE}, /* TAG_DD */
  70         {"blockquote",  HTML_CLRLINE}, /* TAG_BLOCKQUOTE */
  71         {"pre",         HTML_CLRLINE }, /* TAG_PRE */
  72         {"b",           0 }, /* TAG_B */
  73         {"i",           0 }, /* TAG_I */
  74         {"code",        0 }, /* TAG_CODE */
  75         {"small",       0 }, /* TAG_SMALL */
  76         {"style",       HTML_CLRLINE}, /* TAG_STYLE */
  77 };
  78
  79 static  const char      *const htmlattrs[ATTR_MAX] = {
  80         "name", /* ATTR_NAME */
  81         "rel", /* ATTR_REL */
  82         "href", /* ATTR_HREF */
  83         "type", /* ATTR_TYPE */
  84         "media", /* ATTR_MEDIA */
  85         "class", /* ATTR_CLASS */
  86         "style", /* ATTR_STYLE */
  87         "id", /* ATTR_ID */
  88         "colspan", /* ATTR_COLSPAN */
  89         "charset", /* ATTR_CHARSET */
  90 };
  91
  92 static  const char      *const roffscales[SCALE_MAX] = {
  93         "cm", /* SCALE_CM */
  94         "in", /* SCALE_IN */
  95         "pc", /* SCALE_PC */
  96         "pt", /* SCALE_PT */
  97         "em", /* SCALE_EM */
  98         "em", /* SCALE_MM */
  99         "ex", /* SCALE_EN */
 100         "ex", /* SCALE_BU */
 101         "em", /* SCALE_VS */
 102         "ex", /* SCALE_FS */
 103 };
 104
 105 static  void     bufncat(struct html *, const char *, size_t);
 106 static  void     print_ctag(struct html *, enum htmltag);
 107 static  int      print_escape(char);
 108 static  int      print_encode(struct html *, const char *, int);
 109 static  void     print_metaf(struct html *, enum mandoc_esc);
 110 static  void     print_attr(struct html *, const char *, const char *);
 111 static  void     *ml_alloc(char *, enum htmltype);
 112
 113
 114 static void *
 115 ml_alloc(char *outopts, enum htmltype type)
 116 {
 117         struct html     *h;
 118         const char      *toks[5];
 119         char            *v;
 120
 121         toks[0] = "style";
 122         toks[1] = "man";
 123         toks[2] = "includes";
 124         toks[3] = "fragment";
 125         toks[4] = NULL;
 126
 127         h = mandoc_calloc(1, sizeof(struct html));
 128
 129         h->type = type;
 130         h->tags.head = NULL;
 131         h->symtab = mchars_alloc();
 132
 133         while (outopts && *outopts)
 134                 switch (getsubopt(&outopts, UNCONST(toks), &v)) {
 135                 case 0:
 136                         h->style = v;
 137                         break;
 138                 case 1:
 139                         h->base_man = v;
 140                         break;
 141                 case 2:
 142                         h->base_includes = v;
 143                         break;
 144                 case 3:
 145                         h->oflags |= HTML_FRAGMENT;
 146                         break;
 147                 default:
 148                         break;
 149                 }
 150
 151         return(h);
 152 }
 153
 154 void *
 155 html_alloc(char *outopts)
 156 {
 157
 158         return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
 159 }
 160
 161 void *
 162 xhtml_alloc(char *outopts)
 163 {
 164
 165         return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
 166 }
 167
 168 void
 169 html_free(void *p)
 170 {
 171         struct tag      *tag;
 172         struct html     *h;
 173
 174         h = (struct html *)p;
 175
 176         while ((tag = h->tags.head) != NULL) {
 177                 h->tags.head = tag->next;
 178                 free(tag);
 179         }
 180
 181         if (h->symtab)
 182                 mchars_free(h->symtab);
 183
 184         free(h);
 185 }
 186
 187 void
 188 print_gen_head(struct html *h)
 189 {
 190         struct htmlpair  tag[4];
 191         struct tag      *t;
 192
 193         tag[0].key = ATTR_CHARSET;
 194         tag[0].val = "utf-8";
 195         print_otag(h, TAG_META, 1, tag);
 196
 197         /*
 198          * Print a default style-sheet.
 199          */
 200         t = print_otag(h, TAG_STYLE, 0, NULL);
 201         print_text(h, "table.head, table.foot { width: 100%; }\n"
 202               "td.head-rtitle, td.foot-os { text-align: right; }\n"
 203               "td.head-vol { text-align: center; }\n"
 204               "table.foot td { width: 50%; }\n"
 205               "table.head td { width: 33%; }\n"
 206               "div.spacer { margin: 1em 0; }\n");
 207         print_tagq(h, t);
 208
 209         if (h->style) {
 210                 tag[0].key = ATTR_REL;
 211                 tag[0].val = "stylesheet";
 212                 tag[1].key = ATTR_HREF;
 213                 tag[1].val = h->style;
 214                 tag[2].key = ATTR_TYPE;
 215                 tag[2].val = "text/css";
 216                 tag[3].key = ATTR_MEDIA;
 217                 tag[3].val = "all";
 218                 print_otag(h, TAG_LINK, 4, tag);
 219         }
 220 }
 221
 222 static void
 223 print_metaf(struct html *h, enum mandoc_esc deco)
 224 {
 225         enum htmlfont    font;
 226
 227         switch (deco) {
 228         case ESCAPE_FONTPREV:
 229                 font = h->metal;
 230                 break;
 231         case ESCAPE_FONTITALIC:
 232                 font = HTMLFONT_ITALIC;
 233                 break;
 234         case ESCAPE_FONTBOLD:
 235                 font = HTMLFONT_BOLD;
 236                 break;
 237         case ESCAPE_FONTBI:
 238                 font = HTMLFONT_BI;
 239                 break;
 240         case ESCAPE_FONT:
 241                 /* FALLTHROUGH */
 242         case ESCAPE_FONTROMAN:
 243                 font = HTMLFONT_NONE;
 244                 break;
 245         default:
 246                 abort();
 247                 /* NOTREACHED */
 248         }
 249
 250         if (h->metaf) {
 251                 print_tagq(h, h->metaf);
 252                 h->metaf = NULL;
 253         }
 254
 255         h->metal = h->metac;
 256         h->metac = font;
 257
 258         switch (font) {
 259         case HTMLFONT_ITALIC:
 260                 h->metaf = print_otag(h, TAG_I, 0, NULL);
 261                 break;
 262         case HTMLFONT_BOLD:
 263                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 264                 break;
 265         case HTMLFONT_BI:
 266                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 267                 print_otag(h, TAG_I, 0, NULL);
 268                 break;
 269         default:
 270                 break;
 271         }
 272 }
 273
 274 int
 275 html_strlen(const char *cp)
 276 {
 277         size_t           rsz;
 278         int              skip, sz;
 279
 280         /*
 281          * Account for escaped sequences within string length
 282          * calculations.  This follows the logic in term_strlen() as we
 283          * must calculate the width of produced strings.
 284          * Assume that characters are always width of "1".  This is
 285          * hacky, but it gets the job done for approximation of widths.
 286          */
 287
 288         sz = 0;
 289         skip = 0;
 290         while (1) {
 291                 rsz = strcspn(cp, "\\");
 292                 if (rsz) {
 293                         cp += rsz;
 294                         if (skip) {
 295                                 skip = 0;
 296                                 rsz--;
 297                         }
 298                         sz += rsz;
 299                 }
 300                 if ('\0' == *cp)
 301                         break;
 302                 cp++;
 303                 switch (mandoc_escape(&cp, NULL, NULL)) {
 304                 case ESCAPE_ERROR:
 305                         return(sz);
 306                 case ESCAPE_UNICODE:
 307                         /* FALLTHROUGH */
 308                 case ESCAPE_NUMBERED:
 309                         /* FALLTHROUGH */
 310                 case ESCAPE_SPECIAL:
 311                         if (skip)
 312                                 skip = 0;
 313                         else
 314                                 sz++;
 315                         break;
 316                 case ESCAPE_SKIPCHAR:
 317                         skip = 1;
 318                         break;
 319                 default:
 320                         break;
 321                 }
 322         }
 323         return(sz);
 324 }
 325
 326 static int
 327 print_escape(char c)
 328 {
 329
 330         switch (c) {
 331         case '<':
 332                 printf("&lt;");
 333                 break;
 334         case '>':
 335                 printf("&gt;");
 336                 break;
 337         case '&':
 338                 printf("&amp;");
 339                 break;
 340         case '"':
 341                 printf("&quot;");
 342                 break;
 343         case ASCII_NBRSP:
 344                 putchar('-');
 345                 break;
 346         case ASCII_HYPH:
 347                 putchar('-');
 348                 /* FALLTHROUGH */
 349         case ASCII_BREAK:
 350                 break;
 351         default:
 352                 return(0);
 353         }
 354         return(1);
 355 }
 356
 357 static int
 358 print_encode(struct html *h, const char *p, int norecurse)
 359 {
 360         size_t           sz;
 361         int              c, len, nospace;
 362         const char      *seq;
 363         enum mandoc_esc  esc;
 364         static const char rejs[9] = { '\\', '<', '>', '&', '"',
 365                 ASCII_NBRSP, ASCII_HYPH, ASCII_BREAK, '\0' };
 366
 367         nospace = 0;
 368
 369         while ('\0' != *p) {
 370                 if (HTML_SKIPCHAR & h->flags && '\\' != *p) {
 371                         h->flags &= ~HTML_SKIPCHAR;
 372                         p++;
 373                         continue;
 374                 }
 375
 376                 sz = strcspn(p, rejs);
 377
 378                 fwrite(p, 1, sz, stdout);
 379                 p += (int)sz;
 380
 381                 if ('\0' == *p)
 382                         break;
 383
 384                 if (print_escape(*p++))
 385                         continue;
 386
 387                 esc = mandoc_escape(&p, &seq, &len);
 388                 if (ESCAPE_ERROR == esc)
 389                         break;
 390
 391                 switch (esc) {
 392                 case ESCAPE_FONT:
 393                         /* FALLTHROUGH */
 394                 case ESCAPE_FONTPREV:
 395                         /* FALLTHROUGH */
 396                 case ESCAPE_FONTBOLD:
 397                         /* FALLTHROUGH */
 398                 case ESCAPE_FONTITALIC:
 399                         /* FALLTHROUGH */
 400                 case ESCAPE_FONTBI:
 401                         /* FALLTHROUGH */
 402                 case ESCAPE_FONTROMAN:
 403                         if (0 == norecurse)
 404                                 print_metaf(h, esc);
 405                         continue;
 406                 case ESCAPE_SKIPCHAR:
 407                         h->flags |= HTML_SKIPCHAR;
 408                         continue;
 409                 default:
 410                         break;
 411                 }
 412
 413                 if (h->flags & HTML_SKIPCHAR) {
 414                         h->flags &= ~HTML_SKIPCHAR;
 415                         continue;
 416                 }
 417
 418                 switch (esc) {
 419                 case ESCAPE_UNICODE:
 420                         /* Skip past "u" header. */
 421                         c = mchars_num2uc(seq + 1, len - 1);
 422                         if ('\0' != c)
 423                                 printf("&#x%x;", c);
 424                         break;
 425                 case ESCAPE_NUMBERED:
 426                         c = mchars_num2char(seq, len);
 427                         if ( ! ('\0' == c || print_escape(c)))
 428                                 putchar(c);
 429                         break;
 430                 case ESCAPE_SPECIAL:
 431                         c = mchars_spec2cp(h->symtab, seq, len);
 432                         if (c > 0)
 433                                 printf("&#%d;", c);
 434                         else if (-1 == c && 1 == len &&
 435                             !print_escape(*seq))
 436                                 putchar((int)*seq);
 437                         break;
 438                 case ESCAPE_NOSPACE:
 439                         if ('\0' == *p)
 440                                 nospace = 1;
 441                         break;
 442                 default:
 443                         break;
 444                 }
 445         }
 446
 447         return(nospace);
 448 }
 449
 450 static void
 451 print_attr(struct html *h, const char *key, const char *val)
 452 {
 453         printf(" %s=\"", key);
 454         (void)print_encode(h, val, 1);
 455         putchar('\"');
 456 }
 457
 458 struct tag *
 459 print_otag(struct html *h, enum htmltag tag,
 460                 int sz, const struct htmlpair *p)
 461 {
 462         int              i;
 463         struct tag      *t;
 464
 465         /* Push this tags onto the stack of open scopes. */
 466
 467         if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 468                 t = mandoc_malloc(sizeof(struct tag));
 469                 t->tag = tag;
 470                 t->next = h->tags.head;
 471                 h->tags.head = t;
 472         } else
 473                 t = NULL;
 474
 475         if ( ! (HTML_NOSPACE & h->flags))
 476                 if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 477                         /* Manage keeps! */
 478                         if ( ! (HTML_KEEP & h->flags)) {
 479                                 if (HTML_PREKEEP & h->flags)
 480                                         h->flags |= HTML_KEEP;
 481                                 putchar(' ');
 482                         } else
 483                                 printf("&#160;");
 484                 }
 485
 486         if ( ! (h->flags & HTML_NONOSPACE))
 487                 h->flags &= ~HTML_NOSPACE;
 488         else
 489                 h->flags |= HTML_NOSPACE;
 490
 491         /* Print out the tag name and attributes. */
 492
 493         printf("<%s", htmltags[tag].name);
 494         for (i = 0; i < sz; i++)
 495                 print_attr(h, htmlattrs[p[i].key], p[i].val);
 496
 497         /* Accommodate for XML "well-formed" singleton escaping. */
 498
 499         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 500                 switch (h->type) {
 501                 case HTML_XHTML_1_0_STRICT:
 502                         putchar('/');
 503                         break;
 504                 default:
 505                         break;
 506                 }
 507
 508         putchar('>');
 509
 510         h->flags |= HTML_NOSPACE;
 511
 512         if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
 513                 putchar('\n');
 514
 515         return(t);
 516 }
 517
 518 static void
 519 print_ctag(struct html *h, enum htmltag tag)
 520 {
 521
 522         printf("</%s>", htmltags[tag].name);
 523         if (HTML_CLRLINE & htmltags[tag].flags) {
 524                 h->flags |= HTML_NOSPACE;
 525                 putchar('\n');
 526         }
 527 }
 528
 529 void
 530 print_gen_decls(struct html *h)
 531 {
 532
 533         puts("<!DOCTYPE html>");
 534 }
 535
 536 void
 537 print_text(struct html *h, const char *word)
 538 {
 539
 540         if ( ! (HTML_NOSPACE & h->flags)) {
 541                 /* Manage keeps! */
 542                 if ( ! (HTML_KEEP & h->flags)) {
 543                         if (HTML_PREKEEP & h->flags)
 544                                 h->flags |= HTML_KEEP;
 545                         putchar(' ');
 546                 } else
 547                         printf("&#160;");
 548         }
 549
 550         assert(NULL == h->metaf);
 551         switch (h->metac) {
 552         case HTMLFONT_ITALIC:
 553                 h->metaf = print_otag(h, TAG_I, 0, NULL);
 554                 break;
 555         case HTMLFONT_BOLD:
 556                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 557                 break;
 558         case HTMLFONT_BI:
 559                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 560                 print_otag(h, TAG_I, 0, NULL);
 561                 break;
 562         default:
 563                 break;
 564         }
 565
 566         assert(word);
 567         if ( ! print_encode(h, word, 0)) {
 568                 if ( ! (h->flags & HTML_NONOSPACE))
 569                         h->flags &= ~HTML_NOSPACE;
 570         } else
 571                 h->flags |= HTML_NOSPACE;
 572
 573         if (h->metaf) {
 574                 print_tagq(h, h->metaf);
 575                 h->metaf = NULL;
 576         }
 577
 578         h->flags &= ~HTML_IGNDELIM;
 579 }
 580
 581 void
 582 print_tagq(struct html *h, const struct tag *until)
 583 {
 584         struct tag      *tag;
 585
 586         while ((tag = h->tags.head) != NULL) {
 587                 /*
 588                  * Remember to close out and nullify the current
 589                  * meta-font and table, if applicable.
 590                  */
 591                 if (tag == h->metaf)
 592                         h->metaf = NULL;
 593                 if (tag == h->tblt)
 594                         h->tblt = NULL;
 595                 print_ctag(h, tag->tag);
 596                 h->tags.head = tag->next;
 597                 free(tag);
 598                 if (until && tag == until)
 599                         return;
 600         }
 601 }
 602
 603 void
 604 print_stagq(struct html *h, const struct tag *suntil)
 605 {
 606         struct tag      *tag;
 607
 608         while ((tag = h->tags.head) != NULL) {
 609                 if (suntil && tag == suntil)
 610                         return;
 611                 /*
 612                  * Remember to close out and nullify the current
 613                  * meta-font and table, if applicable.
 614                  */
 615                 if (tag == h->metaf)
 616                         h->metaf = NULL;
 617                 if (tag == h->tblt)
 618                         h->tblt = NULL;
 619                 print_ctag(h, tag->tag);
 620                 h->tags.head = tag->next;
 621                 free(tag);
 622         }
 623 }
 624
 625 void
 626 print_paragraph(struct html *h)
 627 {
 628         struct tag      *t;
 629         struct htmlpair  tag;
 630
 631         PAIR_CLASS_INIT(&tag, "spacer");
 632         t = print_otag(h, TAG_DIV, 1, &tag);
 633         print_tagq(h, t);
 634 }
 635
 636
 637 void
 638 bufinit(struct html *h)
 639 {
 640
 641         h->buf[0] = '\0';
 642         h->buflen = 0;
 643 }
 644
 645 void
 646 bufcat_style(struct html *h, const char *key, const char *val)
 647 {
 648
 649         bufcat(h, key);
 650         bufcat(h, ":");
 651         bufcat(h, val);
 652         bufcat(h, ";");
 653 }
 654
 655 void
 656 bufcat(struct html *h, const char *p)
 657 {
 658
 659         /*
 660          * XXX This is broken and not easy to fix.
 661          * When using the -Oincludes option, buffmt_includes()
 662          * may pass in strings overrunning BUFSIZ, causing a crash.
 663          */
 664
 665         h->buflen = strlcat(h->buf, p, BUFSIZ);
 666         assert(h->buflen < BUFSIZ);
 667 }
 668
 669 void
 670 bufcat_fmt(struct html *h, const char *fmt, ...)
 671 {
 672         va_list          ap;
 673
 674         va_start(ap, fmt);
 675         (void)vsnprintf(h->buf + (int)h->buflen,
 676             BUFSIZ - h->buflen - 1, fmt, ap);
 677         va_end(ap);
 678         h->buflen = strlen(h->buf);
 679 }
 680
 681 static void
 682 bufncat(struct html *h, const char *p, size_t sz)
 683 {
 684
 685         assert(h->buflen + sz + 1 < BUFSIZ);
 686         strncat(h->buf, p, sz);
 687         h->buflen += sz;
 688 }
 689
 690 void
 691 buffmt_includes(struct html *h, const char *name)
 692 {
 693         const char      *p, *pp;
 694
 695         pp = h->base_includes;
 696
 697         bufinit(h);
 698         while (NULL != (p = strchr(pp, '%'))) {
 699                 bufncat(h, pp, (size_t)(p - pp));
 700                 switch (*(p + 1)) {
 701                 case'I':
 702                         bufcat(h, name);
 703                         break;
 704                 default:
 705                         bufncat(h, p, 2);
 706                         break;
 707                 }
 708                 pp = p + 2;
 709         }
 710         if (pp)
 711                 bufcat(h, pp);
 712 }
 713
 714 void
 715 buffmt_man(struct html *h, const char *name, const char *sec)
 716 {
 717         const char      *p, *pp;
 718
 719         pp = h->base_man;
 720
 721         bufinit(h);
 722         while (NULL != (p = strchr(pp, '%'))) {
 723                 bufncat(h, pp, (size_t)(p - pp));
 724                 switch (*(p + 1)) {
 725                 case 'S':
 726                         bufcat(h, sec ? sec : "1");
 727                         break;
 728                 case 'N':
 729                         bufcat_fmt(h, "%s", name);
 730                         break;
 731                 default:
 732                         bufncat(h, p, 2);
 733                         break;
 734                 }
 735                 pp = p + 2;
 736         }
 737         if (pp)
 738                 bufcat(h, pp);
 739 }
 740
 741 void
 742 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 743 {
 744         double           v;
 745
 746         v = su->scale;
 747         if (SCALE_MM == su->unit && 0.0 == (v /= 100.0))
 748                 v = 1.0;
 749         else if (SCALE_BU == su->unit)
 750                 v /= 24.0;
 751
 752         bufcat_fmt(h, "%s: %.2f%s;", p, v, roffscales[su->unit]);
 753 }
 754
 755 void
 756 bufcat_id(struct html *h, const char *src)
 757 {
 758
 759         /* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */
 760
 761         while ('\0' != *src)
 762                 bufcat_fmt(h, "%.2x", *src++);
 763 }