html.c

   1 /*      $Id: html.c,v 1.151 2012/05/31 22:29:13 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2011, 2012 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 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21
  22 #include <sys/types.h>
  23
  24 #include <assert.h>
  25 #include <ctype.h>
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28 #include <stdint.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32
  33 #include "mandoc.h"
  34 #include "libmandoc.h"
  35 #include "out.h"
  36 #include "html.h"
  37 #include "main.h"
  38
  39 struct  htmldata {
  40         const char       *name;
  41         int               flags;
  42 #define HTML_CLRLINE     (1 << 0)
  43 #define HTML_NOSTACK     (1 << 1)
  44 #define HTML_AUTOCLOSE   (1 << 2) /* Tag has auto-closure. */
  45 };
  46
  47 static  const struct htmldata htmltags[TAG_MAX] = {
  48         {"html",        HTML_CLRLINE}, /* TAG_HTML */
  49         {"head",        HTML_CLRLINE}, /* TAG_HEAD */
  50         {"body",        HTML_CLRLINE}, /* TAG_BODY */
  51         {"meta",        HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_META */
  52         {"title",       HTML_CLRLINE}, /* TAG_TITLE */
  53         {"div",         HTML_CLRLINE}, /* TAG_DIV */
  54         {"h1",          0}, /* TAG_H1 */
  55         {"h2",          0}, /* TAG_H2 */
  56         {"span",        0}, /* TAG_SPAN */
  57         {"link",        HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_LINK */
  58         {"br",          HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_BR */
  59         {"a",           0}, /* TAG_A */
  60         {"table",       HTML_CLRLINE}, /* TAG_TABLE */
  61         {"tbody",       HTML_CLRLINE}, /* TAG_TBODY */
  62         {"col",         HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_COL */
  63         {"tr",          HTML_CLRLINE}, /* TAG_TR */
  64         {"td",          HTML_CLRLINE}, /* TAG_TD */
  65         {"li",          HTML_CLRLINE}, /* TAG_LI */
  66         {"ul",          HTML_CLRLINE}, /* TAG_UL */
  67         {"ol",          HTML_CLRLINE}, /* TAG_OL */
  68         {"dl",          HTML_CLRLINE}, /* TAG_DL */
  69         {"dt",          HTML_CLRLINE}, /* TAG_DT */
  70         {"dd",          HTML_CLRLINE}, /* TAG_DD */
  71         {"blockquote",  HTML_CLRLINE}, /* TAG_BLOCKQUOTE */
  72         {"p",           HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_P */
  73         {"pre",         HTML_CLRLINE }, /* TAG_PRE */
  74         {"b",           0 }, /* TAG_B */
  75         {"i",           0 }, /* TAG_I */
  76         {"code",        0 }, /* TAG_CODE */
  77         {"small",       0 }, /* TAG_SMALL */
  78 };
  79
  80 static  const char      *const htmlattrs[ATTR_MAX] = {
  81         "http-equiv", /* ATTR_HTTPEQUIV */
  82         "content", /* ATTR_CONTENT */
  83         "name", /* ATTR_NAME */
  84         "rel", /* ATTR_REL */
  85         "href", /* ATTR_HREF */
  86         "type", /* ATTR_TYPE */
  87         "media", /* ATTR_MEDIA */
  88         "class", /* ATTR_CLASS */
  89         "style", /* ATTR_STYLE */
  90         "width", /* ATTR_WIDTH */
  91         "id", /* ATTR_ID */
  92         "summary", /* ATTR_SUMMARY */
  93         "align", /* ATTR_ALIGN */
  94         "colspan", /* ATTR_COLSPAN */
  95 };
  96
  97 static  const char      *const roffscales[SCALE_MAX] = {
  98         "cm", /* SCALE_CM */
  99         "in", /* SCALE_IN */
 100         "pc", /* SCALE_PC */
 101         "pt", /* SCALE_PT */
 102         "em", /* SCALE_EM */
 103         "em", /* SCALE_MM */
 104         "ex", /* SCALE_EN */
 105         "ex", /* SCALE_BU */
 106         "em", /* SCALE_VS */
 107         "ex", /* SCALE_FS */
 108 };
 109
 110 static  void     bufncat(struct html *, const char *, size_t);
 111 static  void     print_ctag(struct html *, enum htmltag);
 112 static  int      print_encode(struct html *, const char *, int);
 113 static  void     print_metaf(struct html *, enum mandoc_esc);
 114 static  void     print_attr(struct html *, const char *, const char *);
 115 static  void     *ml_alloc(char *, enum htmltype);
 116
 117 static void *
 118 ml_alloc(char *outopts, enum htmltype type)
 119 {
 120         struct html     *h;
 121         const char      *toks[5];
 122         char            *v;
 123
 124         toks[0] = "style";
 125         toks[1] = "man";
 126         toks[2] = "includes";
 127         toks[3] = "fragment";
 128         toks[4] = NULL;
 129
 130         h = mandoc_calloc(1, sizeof(struct html));
 131
 132         h->type = type;
 133         h->tags.head = NULL;
 134         h->symtab = mchars_alloc();
 135
 136         while (outopts && *outopts)
 137                 switch (getsubopt(&outopts, UNCONST(toks), &v)) {
 138                 case (0):
 139                         h->style = v;
 140                         break;
 141                 case (1):
 142                         h->base_man = v;
 143                         break;
 144                 case (2):
 145                         h->base_includes = v;
 146                         break;
 147                 case (3):
 148                         h->oflags |= HTML_FRAGMENT;
 149                         break;
 150                 default:
 151                         break;
 152                 }
 153
 154         return(h);
 155 }
 156
 157 void *
 158 html_alloc(char *outopts)
 159 {
 160
 161         return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
 162 }
 163
 164
 165 void *
 166 xhtml_alloc(char *outopts)
 167 {
 168
 169         return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
 170 }
 171
 172
 173 void
 174 html_free(void *p)
 175 {
 176         struct tag      *tag;
 177         struct html     *h;
 178
 179         h = (struct html *)p;
 180
 181         while ((tag = h->tags.head) != NULL) {
 182                 h->tags.head = tag->next;
 183                 free(tag);
 184         }
 185
 186         if (h->symtab)
 187                 mchars_free(h->symtab);
 188
 189         free(h);
 190 }
 191
 192
 193 void
 194 print_gen_head(struct html *h)
 195 {
 196         struct htmlpair  tag[4];
 197
 198         tag[0].key = ATTR_HTTPEQUIV;
 199         tag[0].val = "Content-Type";
 200         tag[1].key = ATTR_CONTENT;
 201         tag[1].val = "text/html; charset=utf-8";
 202         print_otag(h, TAG_META, 2, tag);
 203
 204         tag[0].key = ATTR_NAME;
 205         tag[0].val = "resource-type";
 206         tag[1].key = ATTR_CONTENT;
 207         tag[1].val = "document";
 208         print_otag(h, TAG_META, 2, tag);
 209
 210         if (h->style) {
 211                 tag[0].key = ATTR_REL;
 212                 tag[0].val = "stylesheet";
 213                 tag[1].key = ATTR_HREF;
 214                 tag[1].val = h->style;
 215                 tag[2].key = ATTR_TYPE;
 216                 tag[2].val = "text/css";
 217                 tag[3].key = ATTR_MEDIA;
 218                 tag[3].val = "all";
 219                 print_otag(h, TAG_LINK, 4, tag);
 220         }
 221 }
 222
 223 static void
 224 print_metaf(struct html *h, enum mandoc_esc deco)
 225 {
 226         enum htmlfont    font;
 227
 228         switch (deco) {
 229         case (ESCAPE_FONTPREV):
 230                 font = h->metal;
 231                 break;
 232         case (ESCAPE_FONTITALIC):
 233                 font = HTMLFONT_ITALIC;
 234                 break;
 235         case (ESCAPE_FONTBOLD):
 236                 font = HTMLFONT_BOLD;
 237                 break;
 238         case (ESCAPE_FONT):
 239                 /* FALLTHROUGH */
 240         case (ESCAPE_FONTROMAN):
 241                 font = HTMLFONT_NONE;
 242                 break;
 243         default:
 244                 abort();
 245                 /* NOTREACHED */
 246         }
 247
 248         if (h->metaf) {
 249                 print_tagq(h, h->metaf);
 250                 h->metaf = NULL;
 251         }
 252
 253         h->metal = h->metac;
 254         h->metac = font;
 255
 256         if (HTMLFONT_NONE != font)
 257                 h->metaf = HTMLFONT_BOLD == font ?
 258                         print_otag(h, TAG_B, 0, NULL) :
 259                         print_otag(h, TAG_I, 0, NULL);
 260 }
 261
 262 int
 263 html_strlen(const char *cp)
 264 {
 265         size_t           rsz;
 266         int              skip, sz;
 267
 268         /*
 269          * Account for escaped sequences within string length
 270          * calculations.  This follows the logic in term_strlen() as we
 271          * must calculate the width of produced strings.
 272          * Assume that characters are always width of "1".  This is
 273          * hacky, but it gets the job done for approximation of widths.
 274          */
 275
 276         sz = 0;
 277         skip = 0;
 278         while (1) {
 279                 rsz = strcspn(cp, "\\");
 280                 if (rsz) {
 281                         cp += rsz;
 282                         if (skip) {
 283                                 skip = 0;
 284                                 rsz--;
 285                         }
 286                         sz += rsz;
 287                 }
 288                 if ('\0' == *cp)
 289                         break;
 290                 cp++;
 291                 switch (mandoc_escape(&cp, NULL, NULL)) {
 292                 case (ESCAPE_ERROR):
 293                         return(sz);
 294                 case (ESCAPE_UNICODE):
 295                         /* FALLTHROUGH */
 296                 case (ESCAPE_NUMBERED):
 297                         /* FALLTHROUGH */
 298                 case (ESCAPE_SPECIAL):
 299                         if (skip)
 300                                 skip = 0;
 301                         else
 302                                 sz++;
 303                         break;
 304                 case (ESCAPE_SKIPCHAR):
 305                         skip = 1;
 306                         break;
 307                 default:
 308                         break;
 309                 }
 310         }
 311         return(sz);
 312 }
 313
 314 static int
 315 print_encode(struct html *h, const char *p, int norecurse)
 316 {
 317         size_t           sz;
 318         int              c, len, nospace;
 319         const char      *seq;
 320         enum mandoc_esc  esc;
 321         static const char rejs[6] = { '\\', '<', '>', '&', ASCII_HYPH, '\0' };
 322
 323         nospace = 0;
 324
 325         while ('\0' != *p) {
 326                 if (HTML_SKIPCHAR & h->flags && '\\' != *p) {
 327                         h->flags &= ~HTML_SKIPCHAR;
 328                         p++;
 329                         continue;
 330                 }
 331
 332                 sz = strcspn(p, rejs);
 333
 334                 fwrite(p, 1, sz, stdout);
 335                 p += (int)sz;
 336
 337                 if ('\0' == *p)
 338                         break;
 339
 340                 switch (*p++) {
 341                 case ('<'):
 342                         printf("&lt;");
 343                         continue;
 344                 case ('>'):
 345                         printf("&gt;");
 346                         continue;
 347                 case ('&'):
 348                         printf("&amp;");
 349                         continue;
 350                 case (ASCII_HYPH):
 351                         putchar('-');
 352                         continue;
 353                 default:
 354                         break;
 355                 }
 356
 357                 esc = mandoc_escape(&p, &seq, &len);
 358                 if (ESCAPE_ERROR == esc)
 359                         break;
 360
 361                 switch (esc) {
 362                 case (ESCAPE_FONT):
 363                         /* FALLTHROUGH */
 364                 case (ESCAPE_FONTPREV):
 365                         /* FALLTHROUGH */
 366                 case (ESCAPE_FONTBOLD):
 367                         /* FALLTHROUGH */
 368                 case (ESCAPE_FONTITALIC):
 369                         /* FALLTHROUGH */
 370                 case (ESCAPE_FONTROMAN):
 371                         if (0 == norecurse)
 372                                 print_metaf(h, esc);
 373                         continue;
 374                 case (ESCAPE_SKIPCHAR):
 375                         h->flags |= HTML_SKIPCHAR;
 376                         continue;
 377                 default:
 378                         break;
 379                 }
 380
 381                 if (h->flags & HTML_SKIPCHAR) {
 382                         h->flags &= ~HTML_SKIPCHAR;
 383                         continue;
 384                 }
 385
 386                 switch (esc) {
 387                 case (ESCAPE_UNICODE):
 388                         /* Skip passed "u" header. */
 389                         c = mchars_num2uc(seq + 1, len - 1);
 390                         if ('\0' != c)
 391                                 printf("&#x%x;", c);
 392                         break;
 393                 case (ESCAPE_NUMBERED):
 394                         c = mchars_num2char(seq, len);
 395                         if ('\0' != c)
 396                                 putchar(c);
 397                         break;
 398                 case (ESCAPE_SPECIAL):
 399                         c = mchars_spec2cp(h->symtab, seq, len);
 400                         if (c > 0)
 401                                 printf("&#%d;", c);
 402                         else if (-1 == c && 1 == len)
 403                                 putchar((int)*seq);
 404                         break;
 405                 case (ESCAPE_NOSPACE):
 406                         if ('\0' == *p)
 407                                 nospace = 1;
 408                         break;
 409                 default:
 410                         break;
 411                 }
 412         }
 413
 414         return(nospace);
 415 }
 416
 417
 418 static void
 419 print_attr(struct html *h, const char *key, const char *val)
 420 {
 421         printf(" %s=\"", key);
 422         (void)print_encode(h, val, 1);
 423         putchar('\"');
 424 }
 425
 426
 427 struct tag *
 428 print_otag(struct html *h, enum htmltag tag,
 429                 int sz, const struct htmlpair *p)
 430 {
 431         int              i;
 432         struct tag      *t;
 433
 434         /* Push this tags onto the stack of open scopes. */
 435
 436         if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 437                 t = mandoc_malloc(sizeof(struct tag));
 438                 t->tag = tag;
 439                 t->next = h->tags.head;
 440                 h->tags.head = t;
 441         } else
 442                 t = NULL;
 443
 444         if ( ! (HTML_NOSPACE & h->flags))
 445                 if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 446                         /* Manage keeps! */
 447                         if ( ! (HTML_KEEP & h->flags)) {
 448                                 if (HTML_PREKEEP & h->flags)
 449                                         h->flags |= HTML_KEEP;
 450                                 putchar(' ');
 451                         } else
 452                                 printf("&#160;");
 453                 }
 454
 455         if ( ! (h->flags & HTML_NONOSPACE))
 456                 h->flags &= ~HTML_NOSPACE;
 457         else
 458                 h->flags |= HTML_NOSPACE;
 459
 460         /* Print out the tag name and attributes. */
 461
 462         printf("<%s", htmltags[tag].name);
 463         for (i = 0; i < sz; i++)
 464                 print_attr(h, htmlattrs[p[i].key], p[i].val);
 465
 466         /* Add non-overridable attributes. */
 467
 468         if (TAG_HTML == tag && HTML_XHTML_1_0_STRICT == h->type) {
 469                 print_attr(h, "xmlns", "http://www.w3.org/1999/xhtml");
 470                 print_attr(h, "xml:lang", "en");
 471                 print_attr(h, "lang", "en");
 472         }
 473
 474         /* Accommodate for XML "well-formed" singleton escaping. */
 475
 476         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 477                 switch (h->type) {
 478                 case (HTML_XHTML_1_0_STRICT):
 479                         putchar('/');
 480                         break;
 481                 default:
 482                         break;
 483                 }
 484
 485         putchar('>');
 486
 487         h->flags |= HTML_NOSPACE;
 488
 489         if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
 490                 putchar('\n');
 491
 492         return(t);
 493 }
 494
 495
 496 static void
 497 print_ctag(struct html *h, enum htmltag tag)
 498 {
 499
 500         printf("</%s>", htmltags[tag].name);
 501         if (HTML_CLRLINE & htmltags[tag].flags) {
 502                 h->flags |= HTML_NOSPACE;
 503                 putchar('\n');
 504         }
 505 }
 506
 507 void
 508 print_gen_decls(struct html *h)
 509 {
 510         const char      *doctype;
 511         const char      *dtd;
 512         const char      *name;
 513
 514         switch (h->type) {
 515         case (HTML_HTML_4_01_STRICT):
 516                 name = "HTML";
 517                 doctype = "-//W3C//DTD HTML 4.01//EN";
 518                 dtd = "http://www.w3.org/TR/html4/strict.dtd";
 519                 break;
 520         default:
 521                 puts("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 522                 name = "html";
 523                 doctype = "-//W3C//DTD XHTML 1.0 Strict//EN";
 524                 dtd = "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";
 525                 break;
 526         }
 527
 528         printf("<!DOCTYPE %s PUBLIC \"%s\" \"%s\">\n",
 529                         name, doctype, dtd);
 530 }
 531
 532 void
 533 print_text(struct html *h, const char *word)
 534 {
 535
 536         if ( ! (HTML_NOSPACE & h->flags)) {
 537                 /* Manage keeps! */
 538                 if ( ! (HTML_KEEP & h->flags)) {
 539                         if (HTML_PREKEEP & h->flags)
 540                                 h->flags |= HTML_KEEP;
 541                         putchar(' ');
 542                 } else
 543                         printf("&#160;");
 544         }
 545
 546         assert(NULL == h->metaf);
 547         if (HTMLFONT_NONE != h->metac)
 548                 h->metaf = HTMLFONT_BOLD == h->metac ?
 549                         print_otag(h, TAG_B, 0, NULL) :
 550                         print_otag(h, TAG_I, 0, NULL);
 551
 552         assert(word);
 553         if ( ! print_encode(h, word, 0)) {
 554                 if ( ! (h->flags & HTML_NONOSPACE))
 555                         h->flags &= ~HTML_NOSPACE;
 556         } else
 557                 h->flags |= HTML_NOSPACE;
 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
 568 void
 569 print_tagq(struct html *h, const struct tag *until)
 570 {
 571         struct tag      *tag;
 572
 573         while ((tag = h->tags.head) != NULL) {
 574                 /*
 575                  * Remember to close out and nullify the current
 576                  * meta-font and table, if applicable.
 577                  */
 578                 if (tag == h->metaf)
 579                         h->metaf = NULL;
 580                 if (tag == h->tblt)
 581                         h->tblt = NULL;
 582                 print_ctag(h, tag->tag);
 583                 h->tags.head = tag->next;
 584                 free(tag);
 585                 if (until && tag == until)
 586                         return;
 587         }
 588 }
 589
 590
 591 void
 592 print_stagq(struct html *h, const struct tag *suntil)
 593 {
 594         struct tag      *tag;
 595
 596         while ((tag = h->tags.head) != NULL) {
 597                 if (suntil && tag == suntil)
 598                         return;
 599                 /*
 600                  * Remember to close out and nullify the current
 601                  * meta-font and table, if applicable.
 602                  */
 603                 if (tag == h->metaf)
 604                         h->metaf = NULL;
 605                 if (tag == h->tblt)
 606                         h->tblt = NULL;
 607                 print_ctag(h, tag->tag);
 608                 h->tags.head = tag->next;
 609                 free(tag);
 610         }
 611 }
 612
 613 void
 614 bufinit(struct html *h)
 615 {
 616
 617         h->buf[0] = '\0';
 618         h->buflen = 0;
 619 }
 620
 621 void
 622 bufcat_style(struct html *h, const char *key, const char *val)
 623 {
 624
 625         bufcat(h, key);
 626         bufcat(h, ":");
 627         bufcat(h, val);
 628         bufcat(h, ";");
 629 }
 630
 631 void
 632 bufcat(struct html *h, const char *p)
 633 {
 634
 635         h->buflen = strlcat(h->buf, p, BUFSIZ);
 636         assert(h->buflen < BUFSIZ);
 637 }
 638
 639 void
 640 bufcat_fmt(struct html *h, const char *fmt, ...)
 641 {
 642         va_list          ap;
 643
 644         va_start(ap, fmt);
 645         (void)vsnprintf(h->buf + (int)h->buflen,
 646                         BUFSIZ - h->buflen - 1, fmt, ap);
 647         va_end(ap);
 648         h->buflen = strlen(h->buf);
 649 }
 650
 651 static void
 652 bufncat(struct html *h, const char *p, size_t sz)
 653 {
 654
 655         assert(h->buflen + sz + 1 < BUFSIZ);
 656         strncat(h->buf, p, sz);
 657         h->buflen += sz;
 658 }
 659
 660 void
 661 buffmt_includes(struct html *h, const char *name)
 662 {
 663         const char      *p, *pp;
 664
 665         pp = h->base_includes;
 666
 667         bufinit(h);
 668         while (NULL != (p = strchr(pp, '%'))) {
 669                 bufncat(h, pp, (size_t)(p - pp));
 670                 switch (*(p + 1)) {
 671                 case('I'):
 672                         bufcat(h, name);
 673                         break;
 674                 default:
 675                         bufncat(h, p, 2);
 676                         break;
 677                 }
 678                 pp = p + 2;
 679         }
 680         if (pp)
 681                 bufcat(h, pp);
 682 }
 683
 684 void
 685 buffmt_man(struct html *h,
 686                 const char *name, const char *sec)
 687 {
 688         const char      *p, *pp;
 689
 690         pp = h->base_man;
 691
 692         bufinit(h);
 693         while (NULL != (p = strchr(pp, '%'))) {
 694                 bufncat(h, pp, (size_t)(p - pp));
 695                 switch (*(p + 1)) {
 696                 case('S'):
 697                         bufcat(h, sec ? sec : "1");
 698                         break;
 699                 case('N'):
 700                         bufcat_fmt(h, name);
 701                         break;
 702                 default:
 703                         bufncat(h, p, 2);
 704                         break;
 705                 }
 706                 pp = p + 2;
 707         }
 708         if (pp)
 709                 bufcat(h, pp);
 710 }
 711
 712 void
 713 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 714 {
 715         double           v;
 716
 717         v = su->scale;
 718         if (SCALE_MM == su->unit && 0.0 == (v /= 100.0))
 719                 v = 1.0;
 720
 721         bufcat_fmt(h, "%s: %.2f%s;", p, v, roffscales[su->unit]);
 722 }
 723
 724 void
 725 bufcat_id(struct html *h, const char *src)
 726 {
 727
 728         /* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */
 729
 730         while ('\0' != *src)
 731                 bufcat_fmt(h, "%.2x", *src++);
 732 }