html.c

   1 /*      $Id: html.c,v 1.190 2015/10/12 00:15:31 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2011-2015 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 AUTHORS DISCLAIM ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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 "out.h"
  34 #include "html.h"
  35 #include "manconf.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         {"math",        HTML_CLRLINE}, /* TAG_MATH */
  78         {"mrow",        0}, /* TAG_MROW */
  79         {"mi",          0}, /* TAG_MI */
  80         {"mo",          0}, /* TAG_MO */
  81         {"msup",        0}, /* TAG_MSUP */
  82         {"msub",        0}, /* TAG_MSUB */
  83         {"msubsup",     0}, /* TAG_MSUBSUP */
  84         {"mfrac",       0}, /* TAG_MFRAC */
  85         {"msqrt",       0}, /* TAG_MSQRT */
  86         {"mfenced",     0}, /* TAG_MFENCED */
  87         {"mtable",      0}, /* TAG_MTABLE */
  88         {"mtr",         0}, /* TAG_MTR */
  89         {"mtd",         0}, /* TAG_MTD */
  90         {"munderover",  0}, /* TAG_MUNDEROVER */
  91         {"munder",      0}, /* TAG_MUNDER*/
  92         {"mover",       0}, /* TAG_MOVER*/
  93 };
  94
  95 static  const char      *const htmlattrs[ATTR_MAX] = {
  96         "name", /* ATTR_NAME */
  97         "rel", /* ATTR_REL */
  98         "href", /* ATTR_HREF */
  99         "type", /* ATTR_TYPE */
 100         "media", /* ATTR_MEDIA */
 101         "class", /* ATTR_CLASS */
 102         "style", /* ATTR_STYLE */
 103         "id", /* ATTR_ID */
 104         "colspan", /* ATTR_COLSPAN */
 105         "charset", /* ATTR_CHARSET */
 106         "open", /* ATTR_OPEN */
 107         "close", /* ATTR_CLOSE */
 108         "mathvariant", /* ATTR_MATHVARIANT */
 109 };
 110
 111 static  const char      *const roffscales[SCALE_MAX] = {
 112         "cm", /* SCALE_CM */
 113         "in", /* SCALE_IN */
 114         "pc", /* SCALE_PC */
 115         "pt", /* SCALE_PT */
 116         "em", /* SCALE_EM */
 117         "em", /* SCALE_MM */
 118         "ex", /* SCALE_EN */
 119         "ex", /* SCALE_BU */
 120         "em", /* SCALE_VS */
 121         "ex", /* SCALE_FS */
 122 };
 123
 124 static  void     bufncat(struct html *, const char *, size_t);
 125 static  void     print_ctag(struct html *, struct tag *);
 126 static  int      print_escape(char);
 127 static  int      print_encode(struct html *, const char *, int);
 128 static  void     print_metaf(struct html *, enum mandoc_esc);
 129 static  void     print_attr(struct html *, const char *, const char *);
 130
 131
 132 void *
 133 html_alloc(const struct mchars *mchars, const struct manoutput *outopts)
 134 {
 135         struct html     *h;
 136
 137         h = mandoc_calloc(1, sizeof(struct html));
 138
 139         h->tags.head = NULL;
 140         h->symtab = mchars;
 141
 142         h->style = outopts->style;
 143         h->base_man = outopts->man;
 144         h->base_includes = outopts->includes;
 145         if (outopts->fragment)
 146                 h->oflags |= HTML_FRAGMENT;
 147
 148         return h;
 149 }
 150
 151 void
 152 html_free(void *p)
 153 {
 154         struct tag      *tag;
 155         struct html     *h;
 156
 157         h = (struct html *)p;
 158
 159         while ((tag = h->tags.head) != NULL) {
 160                 h->tags.head = tag->next;
 161                 free(tag);
 162         }
 163
 164         free(h);
 165 }
 166
 167 void
 168 print_gen_head(struct html *h)
 169 {
 170         struct htmlpair  tag[4];
 171         struct tag      *t;
 172
 173         tag[0].key = ATTR_CHARSET;
 174         tag[0].val = "utf-8";
 175         print_otag(h, TAG_META, 1, tag);
 176
 177         /*
 178          * Print a default style-sheet.
 179          */
 180         t = print_otag(h, TAG_STYLE, 0, NULL);
 181         print_text(h, "table.head, table.foot { width: 100%; }\n"
 182               "td.head-rtitle, td.foot-os { text-align: right; }\n"
 183               "td.head-vol { text-align: center; }\n"
 184               "table.foot td { width: 50%; }\n"
 185               "table.head td { width: 33%; }\n"
 186               "div.spacer { margin: 1em 0; }\n");
 187         print_tagq(h, t);
 188
 189         if (h->style) {
 190                 tag[0].key = ATTR_REL;
 191                 tag[0].val = "stylesheet";
 192                 tag[1].key = ATTR_HREF;
 193                 tag[1].val = h->style;
 194                 tag[2].key = ATTR_TYPE;
 195                 tag[2].val = "text/css";
 196                 tag[3].key = ATTR_MEDIA;
 197                 tag[3].val = "all";
 198                 print_otag(h, TAG_LINK, 4, tag);
 199         }
 200 }
 201
 202 static void
 203 print_metaf(struct html *h, enum mandoc_esc deco)
 204 {
 205         enum htmlfont    font;
 206
 207         switch (deco) {
 208         case ESCAPE_FONTPREV:
 209                 font = h->metal;
 210                 break;
 211         case ESCAPE_FONTITALIC:
 212                 font = HTMLFONT_ITALIC;
 213                 break;
 214         case ESCAPE_FONTBOLD:
 215                 font = HTMLFONT_BOLD;
 216                 break;
 217         case ESCAPE_FONTBI:
 218                 font = HTMLFONT_BI;
 219                 break;
 220         case ESCAPE_FONT:
 221         case ESCAPE_FONTROMAN:
 222                 font = HTMLFONT_NONE;
 223                 break;
 224         default:
 225                 abort();
 226         }
 227
 228         if (h->metaf) {
 229                 print_tagq(h, h->metaf);
 230                 h->metaf = NULL;
 231         }
 232
 233         h->metal = h->metac;
 234         h->metac = font;
 235
 236         switch (font) {
 237         case HTMLFONT_ITALIC:
 238                 h->metaf = print_otag(h, TAG_I, 0, NULL);
 239                 break;
 240         case HTMLFONT_BOLD:
 241                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 242                 break;
 243         case HTMLFONT_BI:
 244                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 245                 print_otag(h, TAG_I, 0, NULL);
 246                 break;
 247         default:
 248                 break;
 249         }
 250 }
 251
 252 int
 253 html_strlen(const char *cp)
 254 {
 255         size_t           rsz;
 256         int              skip, sz;
 257
 258         /*
 259          * Account for escaped sequences within string length
 260          * calculations.  This follows the logic in term_strlen() as we
 261          * must calculate the width of produced strings.
 262          * Assume that characters are always width of "1".  This is
 263          * hacky, but it gets the job done for approximation of widths.
 264          */
 265
 266         sz = 0;
 267         skip = 0;
 268         while (1) {
 269                 rsz = strcspn(cp, "\\");
 270                 if (rsz) {
 271                         cp += rsz;
 272                         if (skip) {
 273                                 skip = 0;
 274                                 rsz--;
 275                         }
 276                         sz += rsz;
 277                 }
 278                 if ('\0' == *cp)
 279                         break;
 280                 cp++;
 281                 switch (mandoc_escape(&cp, NULL, NULL)) {
 282                 case ESCAPE_ERROR:
 283                         return sz;
 284                 case ESCAPE_UNICODE:
 285                 case ESCAPE_NUMBERED:
 286                 case ESCAPE_SPECIAL:
 287                 case ESCAPE_OVERSTRIKE:
 288                         if (skip)
 289                                 skip = 0;
 290                         else
 291                                 sz++;
 292                         break;
 293                 case ESCAPE_SKIPCHAR:
 294                         skip = 1;
 295                         break;
 296                 default:
 297                         break;
 298                 }
 299         }
 300         return sz;
 301 }
 302
 303 static int
 304 print_escape(char c)
 305 {
 306
 307         switch (c) {
 308         case '<':
 309                 printf("&lt;");
 310                 break;
 311         case '>':
 312                 printf("&gt;");
 313                 break;
 314         case '&':
 315                 printf("&amp;");
 316                 break;
 317         case '"':
 318                 printf("&quot;");
 319                 break;
 320         case ASCII_NBRSP:
 321                 printf("&nbsp;");
 322                 break;
 323         case ASCII_HYPH:
 324                 putchar('-');
 325                 break;
 326         case ASCII_BREAK:
 327                 break;
 328         default:
 329                 return 0;
 330         }
 331         return 1;
 332 }
 333
 334 static int
 335 print_encode(struct html *h, const char *p, int norecurse)
 336 {
 337         size_t           sz;
 338         int              c, len, nospace;
 339         const char      *seq;
 340         enum mandoc_esc  esc;
 341         static const char rejs[9] = { '\\', '<', '>', '&', '"',
 342                 ASCII_NBRSP, ASCII_HYPH, ASCII_BREAK, '\0' };
 343
 344         nospace = 0;
 345
 346         while ('\0' != *p) {
 347                 if (HTML_SKIPCHAR & h->flags && '\\' != *p) {
 348                         h->flags &= ~HTML_SKIPCHAR;
 349                         p++;
 350                         continue;
 351                 }
 352
 353                 sz = strcspn(p, rejs);
 354
 355                 fwrite(p, 1, sz, stdout);
 356                 p += (int)sz;
 357
 358                 if ('\0' == *p)
 359                         break;
 360
 361                 if (print_escape(*p++))
 362                         continue;
 363
 364                 esc = mandoc_escape(&p, &seq, &len);
 365                 if (ESCAPE_ERROR == esc)
 366                         break;
 367
 368                 switch (esc) {
 369                 case ESCAPE_FONT:
 370                 case ESCAPE_FONTPREV:
 371                 case ESCAPE_FONTBOLD:
 372                 case ESCAPE_FONTITALIC:
 373                 case ESCAPE_FONTBI:
 374                 case ESCAPE_FONTROMAN:
 375                         if (0 == norecurse)
 376                                 print_metaf(h, esc);
 377                         continue;
 378                 case ESCAPE_SKIPCHAR:
 379                         h->flags |= HTML_SKIPCHAR;
 380                         continue;
 381                 default:
 382                         break;
 383                 }
 384
 385                 if (h->flags & HTML_SKIPCHAR) {
 386                         h->flags &= ~HTML_SKIPCHAR;
 387                         continue;
 388                 }
 389
 390                 switch (esc) {
 391                 case ESCAPE_UNICODE:
 392                         /* Skip past "u" header. */
 393                         c = mchars_num2uc(seq + 1, len - 1);
 394                         break;
 395                 case ESCAPE_NUMBERED:
 396                         c = mchars_num2char(seq, len);
 397                         if (c < 0)
 398                                 continue;
 399                         break;
 400                 case ESCAPE_SPECIAL:
 401                         c = mchars_spec2cp(h->symtab, seq, len);
 402                         if (c <= 0)
 403                                 continue;
 404                         break;
 405                 case ESCAPE_NOSPACE:
 406                         if ('\0' == *p)
 407                                 nospace = 1;
 408                         continue;
 409                 case ESCAPE_OVERSTRIKE:
 410                         if (len == 0)
 411                                 continue;
 412                         c = seq[len - 1];
 413                         break;
 414                 default:
 415                         continue;
 416                 }
 417                 if ((c < 0x20 && c != 0x09) ||
 418                     (c > 0x7E && c < 0xA0))
 419                         c = 0xFFFD;
 420                 if (c > 0x7E)
 421                         printf("&#%d;", c);
 422                 else if ( ! print_escape(c))
 423                         putchar(c);
 424         }
 425
 426         return nospace;
 427 }
 428
 429 static void
 430 print_attr(struct html *h, const char *key, const char *val)
 431 {
 432         printf(" %s=\"", key);
 433         (void)print_encode(h, val, 1);
 434         putchar('\"');
 435 }
 436
 437 struct tag *
 438 print_otag(struct html *h, enum htmltag tag,
 439                 int sz, const struct htmlpair *p)
 440 {
 441         int              i;
 442         struct tag      *t;
 443
 444         /* Push this tags onto the stack of open scopes. */
 445
 446         if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 447                 t = mandoc_malloc(sizeof(struct tag));
 448                 t->tag = tag;
 449                 t->next = h->tags.head;
 450                 h->tags.head = t;
 451         } else
 452                 t = NULL;
 453
 454         if ( ! (HTML_NOSPACE & h->flags))
 455                 if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 456                         /* Manage keeps! */
 457                         if ( ! (HTML_KEEP & h->flags)) {
 458                                 if (HTML_PREKEEP & h->flags)
 459                                         h->flags |= HTML_KEEP;
 460                                 putchar(' ');
 461                         } else
 462                                 printf("&#160;");
 463                 }
 464
 465         if ( ! (h->flags & HTML_NONOSPACE))
 466                 h->flags &= ~HTML_NOSPACE;
 467         else
 468                 h->flags |= HTML_NOSPACE;
 469
 470         /* Print out the tag name and attributes. */
 471
 472         printf("<%s", htmltags[tag].name);
 473         for (i = 0; i < sz; i++)
 474                 print_attr(h, htmlattrs[p[i].key], p[i].val);
 475
 476         /* Accommodate for "well-formed" singleton escaping. */
 477
 478         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 479                 putchar('/');
 480
 481         putchar('>');
 482
 483         h->flags |= HTML_NOSPACE;
 484
 485         if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
 486                 putchar('\n');
 487
 488         return t;
 489 }
 490
 491 static void
 492 print_ctag(struct html *h, struct tag *tag)
 493 {
 494
 495         /*
 496          * Remember to close out and nullify the current
 497          * meta-font and table, if applicable.
 498          */
 499         if (tag == h->metaf)
 500                 h->metaf = NULL;
 501         if (tag == h->tblt)
 502                 h->tblt = NULL;
 503
 504         printf("</%s>", htmltags[tag->tag].name);
 505         if (HTML_CLRLINE & htmltags[tag->tag].flags) {
 506                 h->flags |= HTML_NOSPACE;
 507                 putchar('\n');
 508         }
 509
 510         h->tags.head = tag->next;
 511         free(tag);
 512 }
 513
 514 void
 515 print_gen_decls(struct html *h)
 516 {
 517
 518         puts("<!DOCTYPE html>");
 519 }
 520
 521 void
 522 print_text(struct html *h, const char *word)
 523 {
 524
 525         if ( ! (HTML_NOSPACE & h->flags)) {
 526                 /* Manage keeps! */
 527                 if ( ! (HTML_KEEP & h->flags)) {
 528                         if (HTML_PREKEEP & h->flags)
 529                                 h->flags |= HTML_KEEP;
 530                         putchar(' ');
 531                 } else
 532                         printf("&#160;");
 533         }
 534
 535         assert(NULL == h->metaf);
 536         switch (h->metac) {
 537         case HTMLFONT_ITALIC:
 538                 h->metaf = print_otag(h, TAG_I, 0, NULL);
 539                 break;
 540         case HTMLFONT_BOLD:
 541                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 542                 break;
 543         case HTMLFONT_BI:
 544                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 545                 print_otag(h, TAG_I, 0, NULL);
 546                 break;
 547         default:
 548                 break;
 549         }
 550
 551         assert(word);
 552         if ( ! print_encode(h, word, 0)) {
 553                 if ( ! (h->flags & HTML_NONOSPACE))
 554                         h->flags &= ~HTML_NOSPACE;
 555                 h->flags &= ~HTML_NONEWLINE;
 556         } else
 557                 h->flags |= HTML_NOSPACE | HTML_NONEWLINE;
 558
 559         if (h->metaf) {
 560                 print_tagq(h, h->metaf);
 561                 h->metaf = NULL;
 562         }
 563
 564         h->flags &= ~HTML_IGNDELIM;
 565 }
 566
 567 void
 568 print_tagq(struct html *h, const struct tag *until)
 569 {
 570         struct tag      *tag;
 571
 572         while ((tag = h->tags.head) != NULL) {
 573                 print_ctag(h, tag);
 574                 if (until && tag == until)
 575                         return;
 576         }
 577 }
 578
 579 void
 580 print_stagq(struct html *h, const struct tag *suntil)
 581 {
 582         struct tag      *tag;
 583
 584         while ((tag = h->tags.head) != NULL) {
 585                 if (suntil && tag == suntil)
 586                         return;
 587                 print_ctag(h, tag);
 588         }
 589 }
 590
 591 void
 592 print_paragraph(struct html *h)
 593 {
 594         struct tag      *t;
 595         struct htmlpair  tag;
 596
 597         PAIR_CLASS_INIT(&tag, "spacer");
 598         t = print_otag(h, TAG_DIV, 1, &tag);
 599         print_tagq(h, t);
 600 }
 601
 602
 603 void
 604 bufinit(struct html *h)
 605 {
 606
 607         h->buf[0] = '\0';
 608         h->buflen = 0;
 609 }
 610
 611 void
 612 bufcat_style(struct html *h, const char *key, const char *val)
 613 {
 614
 615         bufcat(h, key);
 616         bufcat(h, ":");
 617         bufcat(h, val);
 618         bufcat(h, ";");
 619 }
 620
 621 void
 622 bufcat(struct html *h, const char *p)
 623 {
 624
 625         /*
 626          * XXX This is broken and not easy to fix.
 627          * When using the -Oincludes option, buffmt_includes()
 628          * may pass in strings overrunning BUFSIZ, causing a crash.
 629          */
 630
 631         h->buflen = strlcat(h->buf, p, BUFSIZ);
 632         assert(h->buflen < BUFSIZ);
 633 }
 634
 635 void
 636 bufcat_fmt(struct html *h, const char *fmt, ...)
 637 {
 638         va_list          ap;
 639
 640         va_start(ap, fmt);
 641         (void)vsnprintf(h->buf + (int)h->buflen,
 642             BUFSIZ - h->buflen - 1, fmt, ap);
 643         va_end(ap);
 644         h->buflen = strlen(h->buf);
 645 }
 646
 647 static void
 648 bufncat(struct html *h, const char *p, size_t sz)
 649 {
 650
 651         assert(h->buflen + sz + 1 < BUFSIZ);
 652         strncat(h->buf, p, sz);
 653         h->buflen += sz;
 654 }
 655
 656 void
 657 buffmt_includes(struct html *h, const char *name)
 658 {
 659         const char      *p, *pp;
 660
 661         pp = h->base_includes;
 662
 663         bufinit(h);
 664         while (NULL != (p = strchr(pp, '%'))) {
 665                 bufncat(h, pp, (size_t)(p - pp));
 666                 switch (*(p + 1)) {
 667                 case'I':
 668                         bufcat(h, name);
 669                         break;
 670                 default:
 671                         bufncat(h, p, 2);
 672                         break;
 673                 }
 674                 pp = p + 2;
 675         }
 676         if (pp)
 677                 bufcat(h, pp);
 678 }
 679
 680 void
 681 buffmt_man(struct html *h, const char *name, const char *sec)
 682 {
 683         const char      *p, *pp;
 684
 685         pp = h->base_man;
 686
 687         bufinit(h);
 688         while (NULL != (p = strchr(pp, '%'))) {
 689                 bufncat(h, pp, (size_t)(p - pp));
 690                 switch (*(p + 1)) {
 691                 case 'S':
 692                         bufcat(h, sec ? sec : "1");
 693                         break;
 694                 case 'N':
 695                         bufcat_fmt(h, "%s", name);
 696                         break;
 697                 default:
 698                         bufncat(h, p, 2);
 699                         break;
 700                 }
 701                 pp = p + 2;
 702         }
 703         if (pp)
 704                 bufcat(h, pp);
 705 }
 706
 707 void
 708 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 709 {
 710         double           v;
 711
 712         v = su->scale;
 713         if (SCALE_MM == su->unit && 0.0 == (v /= 100.0))
 714                 v = 1.0;
 715         else if (SCALE_BU == su->unit)
 716                 v /= 24.0;
 717
 718         bufcat_fmt(h, "%s: %.2f%s;", p, v, roffscales[su->unit]);
 719 }
 720
 721 void
 722 bufcat_id(struct html *h, const char *src)
 723 {
 724
 725         /* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */
 726
 727         while ('\0' != *src)
 728                 bufcat_fmt(h, "%.2x", *src++);
 729 }