html.c

   1 /*      $Id: html.c,v 1.163 2014/08/14 00:31:43 schwarze 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         {"p",           HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_P */
  72         {"pre",         HTML_CLRLINE }, /* TAG_PRE */
  73         {"b",           0 }, /* TAG_B */
  74         {"i",           0 }, /* TAG_I */
  75         {"code",        0 }, /* TAG_CODE */
  76         {"small",       0 }, /* TAG_SMALL */
  77 };
  78
  79 static  const char      *const htmlattrs[ATTR_MAX] = {
  80         "http-equiv", /* ATTR_HTTPEQUIV */
  81         "content", /* ATTR_CONTENT */
  82         "name", /* ATTR_NAME */
  83         "rel", /* ATTR_REL */
  84         "href", /* ATTR_HREF */
  85         "type", /* ATTR_TYPE */
  86         "media", /* ATTR_MEDIA */
  87         "class", /* ATTR_CLASS */
  88         "style", /* ATTR_STYLE */
  89         "width", /* ATTR_WIDTH */
  90         "id", /* ATTR_ID */
  91         "summary", /* ATTR_SUMMARY */
  92         "align", /* ATTR_ALIGN */
  93         "colspan", /* ATTR_COLSPAN */
  94 };
  95
  96 static  const char      *const roffscales[SCALE_MAX] = {
  97         "cm", /* SCALE_CM */
  98         "in", /* SCALE_IN */
  99         "pc", /* SCALE_PC */
 100         "pt", /* SCALE_PT */
 101         "em", /* SCALE_EM */
 102         "em", /* SCALE_MM */
 103         "ex", /* SCALE_EN */
 104         "ex", /* SCALE_BU */
 105         "em", /* SCALE_VS */
 106         "ex", /* SCALE_FS */
 107 };
 108
 109 static  void     bufncat(struct html *, const char *, size_t);
 110 static  void     print_ctag(struct html *, enum htmltag);
 111 static  int      print_escape(char);
 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
 118 static void *
 119 ml_alloc(char *outopts, enum htmltype type)
 120 {
 121         struct html     *h;
 122         const char      *toks[5];
 123         char            *v;
 124
 125         toks[0] = "style";
 126         toks[1] = "man";
 127         toks[2] = "includes";
 128         toks[3] = "fragment";
 129         toks[4] = NULL;
 130
 131         h = mandoc_calloc(1, sizeof(struct html));
 132
 133         h->type = type;
 134         h->tags.head = NULL;
 135         h->symtab = mchars_alloc();
 136
 137         while (outopts && *outopts)
 138                 switch (getsubopt(&outopts, UNCONST(toks), &v)) {
 139                 case 0:
 140                         h->style = v;
 141                         break;
 142                 case 1:
 143                         h->base_man = v;
 144                         break;
 145                 case 2:
 146                         h->base_includes = v;
 147                         break;
 148                 case 3:
 149                         h->oflags |= HTML_FRAGMENT;
 150                         break;
 151                 default:
 152                         break;
 153                 }
 154
 155         return(h);
 156 }
 157
 158 void *
 159 html_alloc(char *outopts)
 160 {
 161
 162         return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
 163 }
 164
 165 void *
 166 xhtml_alloc(char *outopts)
 167 {
 168
 169         return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
 170 }
 171
 172 void
 173 html_free(void *p)
 174 {
 175         struct tag      *tag;
 176         struct html     *h;
 177
 178         h = (struct html *)p;
 179
 180         while ((tag = h->tags.head) != NULL) {
 181                 h->tags.head = tag->next;
 182                 free(tag);
 183         }
 184
 185         if (h->symtab)
 186                 mchars_free(h->symtab);
 187
 188         free(h);
 189 }
 190
 191 void
 192 print_gen_head(struct html *h)
 193 {
 194         struct htmlpair  tag[4];
 195
 196         tag[0].key = ATTR_HTTPEQUIV;
 197         tag[0].val = "Content-Type";
 198         tag[1].key = ATTR_CONTENT;
 199         tag[1].val = "text/html; charset=utf-8";
 200         print_otag(h, TAG_META, 2, tag);
 201
 202         tag[0].key = ATTR_NAME;
 203         tag[0].val = "resource-type";
 204         tag[1].key = ATTR_CONTENT;
 205         tag[1].val = "document";
 206         print_otag(h, TAG_META, 2, tag);
 207
 208         if (h->style) {
 209                 tag[0].key = ATTR_REL;
 210                 tag[0].val = "stylesheet";
 211                 tag[1].key = ATTR_HREF;
 212                 tag[1].val = h->style;
 213                 tag[2].key = ATTR_TYPE;
 214                 tag[2].val = "text/css";
 215                 tag[3].key = ATTR_MEDIA;
 216                 tag[3].val = "all";
 217                 print_otag(h, TAG_LINK, 4, tag);
 218         }
 219 }
 220
 221 static void
 222 print_metaf(struct html *h, enum mandoc_esc deco)
 223 {
 224         enum htmlfont    font;
 225
 226         switch (deco) {
 227         case ESCAPE_FONTPREV:
 228                 font = h->metal;
 229                 break;
 230         case ESCAPE_FONTITALIC:
 231                 font = HTMLFONT_ITALIC;
 232                 break;
 233         case ESCAPE_FONTBOLD:
 234                 font = HTMLFONT_BOLD;
 235                 break;
 236         case ESCAPE_FONTBI:
 237                 font = HTMLFONT_BI;
 238                 break;
 239         case ESCAPE_FONT:
 240                 /* FALLTHROUGH */
 241         case ESCAPE_FONTROMAN:
 242                 font = HTMLFONT_NONE;
 243                 break;
 244         default:
 245                 abort();
 246                 /* NOTREACHED */
 247         }
 248
 249         if (h->metaf) {
 250                 print_tagq(h, h->metaf);
 251                 h->metaf = NULL;
 252         }
 253
 254         h->metal = h->metac;
 255         h->metac = font;
 256
 257         switch (font) {
 258         case HTMLFONT_ITALIC:
 259                 h->metaf = print_otag(h, TAG_I, 0, NULL);
 260                 break;
 261         case HTMLFONT_BOLD:
 262                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 263                 break;
 264         case HTMLFONT_BI:
 265                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 266                 print_otag(h, TAG_I, 0, NULL);
 267                 break;
 268         default:
 269                 break;
 270         }
 271 }
 272
 273 int
 274 html_strlen(const char *cp)
 275 {
 276         size_t           rsz;
 277         int              skip, sz;
 278
 279         /*
 280          * Account for escaped sequences within string length
 281          * calculations.  This follows the logic in term_strlen() as we
 282          * must calculate the width of produced strings.
 283          * Assume that characters are always width of "1".  This is
 284          * hacky, but it gets the job done for approximation of widths.
 285          */
 286
 287         sz = 0;
 288         skip = 0;
 289         while (1) {
 290                 rsz = strcspn(cp, "\\");
 291                 if (rsz) {
 292                         cp += rsz;
 293                         if (skip) {
 294                                 skip = 0;
 295                                 rsz--;
 296                         }
 297                         sz += rsz;
 298                 }
 299                 if ('\0' == *cp)
 300                         break;
 301                 cp++;
 302                 switch (mandoc_escape(&cp, NULL, NULL)) {
 303                 case ESCAPE_ERROR:
 304                         return(sz);
 305                 case ESCAPE_UNICODE:
 306                         /* FALLTHROUGH */
 307                 case ESCAPE_NUMBERED:
 308                         /* FALLTHROUGH */
 309                 case ESCAPE_SPECIAL:
 310                         if (skip)
 311                                 skip = 0;
 312                         else
 313                                 sz++;
 314                         break;
 315                 case ESCAPE_SKIPCHAR:
 316                         skip = 1;
 317                         break;
 318                 default:
 319                         break;
 320                 }
 321         }
 322         return(sz);
 323 }
 324
 325 static int
 326 print_escape(char c)
 327 {
 328
 329         switch (c) {
 330         case '<':
 331                 printf("&lt;");
 332                 break;
 333         case '>':
 334                 printf("&gt;");
 335                 break;
 336         case '&':
 337                 printf("&amp;");
 338                 break;
 339         case '"':
 340                 printf("&quot;");
 341                 break;
 342         case ASCII_NBRSP:
 343                 putchar('-');
 344                 break;
 345         case ASCII_HYPH:
 346                 putchar('-');
 347                 /* FALLTHROUGH */
 348         case ASCII_BREAK:
 349                 break;
 350         default:
 351                 return(0);
 352         }
 353         return(1);
 354 }
 355
 356 static int
 357 print_encode(struct html *h, const char *p, int norecurse)
 358 {
 359         size_t           sz;
 360         int              c, len, nospace;
 361         const char      *seq;
 362         enum mandoc_esc  esc;
 363         static const char rejs[9] = { '\\', '<', '>', '&', '"',
 364                 ASCII_NBRSP, ASCII_HYPH, ASCII_BREAK, '\0' };
 365
 366         nospace = 0;
 367
 368         while ('\0' != *p) {
 369                 if (HTML_SKIPCHAR & h->flags && '\\' != *p) {
 370                         h->flags &= ~HTML_SKIPCHAR;
 371                         p++;
 372                         continue;
 373                 }
 374
 375                 sz = strcspn(p, rejs);
 376
 377                 fwrite(p, 1, sz, stdout);
 378                 p += (int)sz;
 379
 380                 if ('\0' == *p)
 381                         break;
 382
 383                 if (print_escape(*p++))
 384                         continue;
 385
 386                 esc = mandoc_escape(&p, &seq, &len);
 387                 if (ESCAPE_ERROR == esc)
 388                         break;
 389
 390                 switch (esc) {
 391                 case ESCAPE_FONT:
 392                         /* FALLTHROUGH */
 393                 case ESCAPE_FONTPREV:
 394                         /* FALLTHROUGH */
 395                 case ESCAPE_FONTBOLD:
 396                         /* FALLTHROUGH */
 397                 case ESCAPE_FONTITALIC:
 398                         /* FALLTHROUGH */
 399                 case ESCAPE_FONTBI:
 400                         /* FALLTHROUGH */
 401                 case ESCAPE_FONTROMAN:
 402                         if (0 == norecurse)
 403                                 print_metaf(h, esc);
 404                         continue;
 405                 case ESCAPE_SKIPCHAR:
 406                         h->flags |= HTML_SKIPCHAR;
 407                         continue;
 408                 default:
 409                         break;
 410                 }
 411
 412                 if (h->flags & HTML_SKIPCHAR) {
 413                         h->flags &= ~HTML_SKIPCHAR;
 414                         continue;
 415                 }
 416
 417                 switch (esc) {
 418                 case ESCAPE_UNICODE:
 419                         /* Skip past "u" header. */
 420                         c = mchars_num2uc(seq + 1, len - 1);
 421                         if ('\0' != c)
 422                                 printf("&#x%x;", c);
 423                         break;
 424                 case ESCAPE_NUMBERED:
 425                         c = mchars_num2char(seq, len);
 426                         if ( ! ('\0' == c || print_escape(c)))
 427                                 putchar(c);
 428                         break;
 429                 case ESCAPE_SPECIAL:
 430                         c = mchars_spec2cp(h->symtab, seq, len);
 431                         if (c > 0)
 432                                 printf("&#%d;", c);
 433                         else if (-1 == c && 1 == len &&
 434                             !print_escape(*seq))
 435                                 putchar((int)*seq);
 436                         break;
 437                 case ESCAPE_NOSPACE:
 438                         if ('\0' == *p)
 439                                 nospace = 1;
 440                         break;
 441                 default:
 442                         break;
 443                 }
 444         }
 445
 446         return(nospace);
 447 }
 448
 449 static void
 450 print_attr(struct html *h, const char *key, const char *val)
 451 {
 452         printf(" %s=\"", key);
 453         (void)print_encode(h, val, 1);
 454         putchar('\"');
 455 }
 456
 457 struct tag *
 458 print_otag(struct html *h, enum htmltag tag,
 459                 int sz, const struct htmlpair *p)
 460 {
 461         int              i;
 462         struct tag      *t;
 463
 464         /* Push this tags onto the stack of open scopes. */
 465
 466         if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 467                 t = mandoc_malloc(sizeof(struct tag));
 468                 t->tag = tag;
 469                 t->next = h->tags.head;
 470                 h->tags.head = t;
 471         } else
 472                 t = NULL;
 473
 474         if ( ! (HTML_NOSPACE & h->flags))
 475                 if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 476                         /* Manage keeps! */
 477                         if ( ! (HTML_KEEP & h->flags)) {
 478                                 if (HTML_PREKEEP & h->flags)
 479                                         h->flags |= HTML_KEEP;
 480                                 putchar(' ');
 481                         } else
 482                                 printf("&#160;");
 483                 }
 484
 485         if ( ! (h->flags & HTML_NONOSPACE))
 486                 h->flags &= ~HTML_NOSPACE;
 487         else
 488                 h->flags |= HTML_NOSPACE;
 489
 490         /* Print out the tag name and attributes. */
 491
 492         printf("<%s", htmltags[tag].name);
 493         for (i = 0; i < sz; i++)
 494                 print_attr(h, htmlattrs[p[i].key], p[i].val);
 495
 496         /* Add non-overridable attributes. */
 497
 498         if (TAG_HTML == tag && HTML_XHTML_1_0_STRICT == h->type) {
 499                 print_attr(h, "xmlns", "http://www.w3.org/1999/xhtml");
 500                 print_attr(h, "xml:lang", "en");
 501                 print_attr(h, "lang", "en");
 502         }
 503
 504         /* Accommodate for XML "well-formed" singleton escaping. */
 505
 506         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 507                 switch (h->type) {
 508                 case HTML_XHTML_1_0_STRICT:
 509                         putchar('/');
 510                         break;
 511                 default:
 512                         break;
 513                 }
 514
 515         putchar('>');
 516
 517         h->flags |= HTML_NOSPACE;
 518
 519         if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
 520                 putchar('\n');
 521
 522         return(t);
 523 }
 524
 525 static void
 526 print_ctag(struct html *h, enum htmltag tag)
 527 {
 528
 529         printf("</%s>", htmltags[tag].name);
 530         if (HTML_CLRLINE & htmltags[tag].flags) {
 531                 h->flags |= HTML_NOSPACE;
 532                 putchar('\n');
 533         }
 534 }
 535
 536 void
 537 print_gen_decls(struct html *h)
 538 {
 539         const char      *doctype;
 540         const char      *dtd;
 541         const char      *name;
 542
 543         switch (h->type) {
 544         case HTML_HTML_4_01_STRICT:
 545                 name = "HTML";
 546                 doctype = "-//W3C//DTD HTML 4.01//EN";
 547                 dtd = "http://www.w3.org/TR/html4/strict.dtd";
 548                 break;
 549         default:
 550                 puts("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 551                 name = "html";
 552                 doctype = "-//W3C//DTD XHTML 1.0 Strict//EN";
 553                 dtd = "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";
 554                 break;
 555         }
 556
 557         printf("<!DOCTYPE %s PUBLIC \"%s\" \"%s\">\n",
 558             name, doctype, dtd);
 559 }
 560
 561 void
 562 print_text(struct html *h, const char *word)
 563 {
 564
 565         if ( ! (HTML_NOSPACE & h->flags)) {
 566                 /* Manage keeps! */
 567                 if ( ! (HTML_KEEP & h->flags)) {
 568                         if (HTML_PREKEEP & h->flags)
 569                                 h->flags |= HTML_KEEP;
 570                         putchar(' ');
 571                 } else
 572                         printf("&#160;");
 573         }
 574
 575         assert(NULL == h->metaf);
 576         switch (h->metac) {
 577         case HTMLFONT_ITALIC:
 578                 h->metaf = print_otag(h, TAG_I, 0, NULL);
 579                 break;
 580         case HTMLFONT_BOLD:
 581                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 582                 break;
 583         case HTMLFONT_BI:
 584                 h->metaf = print_otag(h, TAG_B, 0, NULL);
 585                 print_otag(h, TAG_I, 0, NULL);
 586                 break;
 587         default:
 588                 break;
 589         }
 590
 591         assert(word);
 592         if ( ! print_encode(h, word, 0)) {
 593                 if ( ! (h->flags & HTML_NONOSPACE))
 594                         h->flags &= ~HTML_NOSPACE;
 595         } else
 596                 h->flags |= HTML_NOSPACE;
 597
 598         if (h->metaf) {
 599                 print_tagq(h, h->metaf);
 600                 h->metaf = NULL;
 601         }
 602
 603         h->flags &= ~HTML_IGNDELIM;
 604 }
 605
 606 void
 607 print_tagq(struct html *h, const struct tag *until)
 608 {
 609         struct tag      *tag;
 610
 611         while ((tag = h->tags.head) != NULL) {
 612                 /*
 613                  * Remember to close out and nullify the current
 614                  * meta-font and table, if applicable.
 615                  */
 616                 if (tag == h->metaf)
 617                         h->metaf = NULL;
 618                 if (tag == h->tblt)
 619                         h->tblt = NULL;
 620                 print_ctag(h, tag->tag);
 621                 h->tags.head = tag->next;
 622                 free(tag);
 623                 if (until && tag == until)
 624                         return;
 625         }
 626 }
 627
 628 void
 629 print_stagq(struct html *h, const struct tag *suntil)
 630 {
 631         struct tag      *tag;
 632
 633         while ((tag = h->tags.head) != NULL) {
 634                 if (suntil && tag == suntil)
 635                         return;
 636                 /*
 637                  * Remember to close out and nullify the current
 638                  * meta-font and table, if applicable.
 639                  */
 640                 if (tag == h->metaf)
 641                         h->metaf = NULL;
 642                 if (tag == h->tblt)
 643                         h->tblt = NULL;
 644                 print_ctag(h, tag->tag);
 645                 h->tags.head = tag->next;
 646                 free(tag);
 647         }
 648 }
 649
 650 void
 651 bufinit(struct html *h)
 652 {
 653
 654         h->buf[0] = '\0';
 655         h->buflen = 0;
 656 }
 657
 658 void
 659 bufcat_style(struct html *h, const char *key, const char *val)
 660 {
 661
 662         bufcat(h, key);
 663         bufcat(h, ":");
 664         bufcat(h, val);
 665         bufcat(h, ";");
 666 }
 667
 668 void
 669 bufcat(struct html *h, const char *p)
 670 {
 671
 672         /*
 673          * XXX This is broken and not easy to fix.
 674          * When using the -Oincludes option, buffmt_includes()
 675          * may pass in strings overrunning BUFSIZ, causing a crash.
 676          */
 677
 678         h->buflen = strlcat(h->buf, p, BUFSIZ);
 679         assert(h->buflen < BUFSIZ);
 680 }
 681
 682 void
 683 bufcat_fmt(struct html *h, const char *fmt, ...)
 684 {
 685         va_list          ap;
 686
 687         va_start(ap, fmt);
 688         (void)vsnprintf(h->buf + (int)h->buflen,
 689             BUFSIZ - h->buflen - 1, fmt, ap);
 690         va_end(ap);
 691         h->buflen = strlen(h->buf);
 692 }
 693
 694 static void
 695 bufncat(struct html *h, const char *p, size_t sz)
 696 {
 697
 698         assert(h->buflen + sz + 1 < BUFSIZ);
 699         strncat(h->buf, p, sz);
 700         h->buflen += sz;
 701 }
 702
 703 void
 704 buffmt_includes(struct html *h, const char *name)
 705 {
 706         const char      *p, *pp;
 707
 708         pp = h->base_includes;
 709
 710         bufinit(h);
 711         while (NULL != (p = strchr(pp, '%'))) {
 712                 bufncat(h, pp, (size_t)(p - pp));
 713                 switch (*(p + 1)) {
 714                 case'I':
 715                         bufcat(h, name);
 716                         break;
 717                 default:
 718                         bufncat(h, p, 2);
 719                         break;
 720                 }
 721                 pp = p + 2;
 722         }
 723         if (pp)
 724                 bufcat(h, pp);
 725 }
 726
 727 void
 728 buffmt_man(struct html *h, const char *name, const char *sec)
 729 {
 730         const char      *p, *pp;
 731
 732         pp = h->base_man;
 733
 734         bufinit(h);
 735         while (NULL != (p = strchr(pp, '%'))) {
 736                 bufncat(h, pp, (size_t)(p - pp));
 737                 switch (*(p + 1)) {
 738                 case 'S':
 739                         bufcat(h, sec ? sec : "1");
 740                         break;
 741                 case 'N':
 742                         bufcat_fmt(h, "%s", name);
 743                         break;
 744                 default:
 745                         bufncat(h, p, 2);
 746                         break;
 747                 }
 748                 pp = p + 2;
 749         }
 750         if (pp)
 751                 bufcat(h, pp);
 752 }
 753
 754 void
 755 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 756 {
 757         double           v;
 758
 759         v = su->scale;
 760         if (SCALE_MM == su->unit && 0.0 == (v /= 100.0))
 761                 v = 1.0;
 762         else if (SCALE_BU == su->unit)
 763                 v /= 24.0;
 764
 765         bufcat_fmt(h, "%s: %.2f%s;", p, v, roffscales[su->unit]);
 766 }
 767
 768 void
 769 bufcat_id(struct html *h, const char *src)
 770 {
 771
 772         /* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */
 773
 774         while ('\0' != *src)
 775                 bufcat_fmt(h, "%.2x", *src++);
 776 }