html.c

   1 /*      $Id: html.c,v 1.126 2011/01/30 16:05:37 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2011 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 "out.h"
  35 #include "chars.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  void              print_num(struct html *, const char *, size_t);
  98 static  void              print_spec(struct html *, enum roffdeco,
  99                                 const char *, size_t);
 100 static  void              print_res(struct html *, const char *, size_t);
 101 static  void              print_ctag(struct html *, enum htmltag);
 102 static  void              print_doctype(struct html *);
 103 static  void              print_xmltype(struct html *);
 104 static  int               print_encode(struct html *, const char *, int);
 105 static  void              print_metaf(struct html *, enum roffdeco);
 106 static  void              print_attr(struct html *,
 107                                 const char *, const char *);
 108 static  void             *ml_alloc(char *, enum htmltype);
 109
 110
 111 static void *
 112 ml_alloc(char *outopts, enum htmltype type)
 113 {
 114         struct html     *h;
 115         const char      *toks[4];
 116         char            *v;
 117
 118         toks[0] = "style";
 119         toks[1] = "man";
 120         toks[2] = "includes";
 121         toks[3] = NULL;
 122
 123         h = calloc(1, sizeof(struct html));
 124         if (NULL == h) {
 125                 perror(NULL);
 126                 exit((int)MANDOCLEVEL_SYSERR);
 127         }
 128
 129         h->type = type;
 130         h->tags.head = NULL;
 131         h->symtab = chars_init(CHARS_HTML);
 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                 default:
 145                         break;
 146                 }
 147
 148         return(h);
 149 }
 150
 151 void *
 152 html_alloc(char *outopts)
 153 {
 154
 155         return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
 156 }
 157
 158
 159 void *
 160 xhtml_alloc(char *outopts)
 161 {
 162
 163         return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
 164 }
 165
 166
 167 void
 168 html_free(void *p)
 169 {
 170         struct tag      *tag;
 171         struct html     *h;
 172
 173         h = (struct html *)p;
 174
 175         while ((tag = h->tags.head) != NULL) {
 176                 h->tags.head = tag->next;
 177                 free(tag);
 178         }
 179
 180         if (h->symtab)
 181                 chars_free(h->symtab);
 182
 183         free(h);
 184 }
 185
 186
 187 void
 188 print_gen_head(struct html *h)
 189 {
 190         struct htmlpair  tag[4];
 191
 192         tag[0].key = ATTR_HTTPEQUIV;
 193         tag[0].val = "Content-Type";
 194         tag[1].key = ATTR_CONTENT;
 195         tag[1].val = "text/html; charset=utf-8";
 196         print_otag(h, TAG_META, 2, tag);
 197
 198         tag[0].key = ATTR_NAME;
 199         tag[0].val = "resource-type";
 200         tag[1].key = ATTR_CONTENT;
 201         tag[1].val = "document";
 202         print_otag(h, TAG_META, 2, tag);
 203
 204         if (h->style) {
 205                 tag[0].key = ATTR_REL;
 206                 tag[0].val = "stylesheet";
 207                 tag[1].key = ATTR_HREF;
 208                 tag[1].val = h->style;
 209                 tag[2].key = ATTR_TYPE;
 210                 tag[2].val = "text/css";
 211                 tag[3].key = ATTR_MEDIA;
 212                 tag[3].val = "all";
 213                 print_otag(h, TAG_LINK, 4, tag);
 214         }
 215 }
 216
 217
 218 static void
 219 print_num(struct html *h, const char *p, size_t len)
 220 {
 221         const char      *rhs;
 222
 223         rhs = chars_num2char(p, len);
 224         if (rhs)
 225                 putchar((int)*rhs);
 226 }
 227
 228
 229 static void
 230 print_spec(struct html *h, enum roffdeco d, const char *p, size_t len)
 231 {
 232         int              cp;
 233         const char      *rhs;
 234         size_t           sz;
 235
 236         if ((cp = chars_spec2cp(h->symtab, p, len)) > 0) {
 237                 printf("&#%d;", cp);
 238                 return;
 239         } else if (-1 == cp && DECO_SSPECIAL == d) {
 240                 fwrite(p, 1, len, stdout);
 241                 return;
 242         } else if (-1 == cp)
 243                 return;
 244
 245         if (NULL != (rhs = chars_spec2str(h->symtab, p, len, &sz)))
 246                 fwrite(rhs, 1, sz, stdout);
 247 }
 248
 249
 250 static void
 251 print_res(struct html *h, const char *p, size_t len)
 252 {
 253         int              cp;
 254         const char      *rhs;
 255         size_t           sz;
 256
 257         if ((cp = chars_res2cp(h->symtab, p, len)) > 0) {
 258                 printf("&#%d;", cp);
 259                 return;
 260         } else if (-1 == cp)
 261                 return;
 262
 263         if (NULL != (rhs = chars_res2str(h->symtab, p, len, &sz)))
 264                 fwrite(rhs, 1, sz, stdout);
 265 }
 266
 267
 268 static void
 269 print_metaf(struct html *h, enum roffdeco deco)
 270 {
 271         enum htmlfont    font;
 272
 273         switch (deco) {
 274         case (DECO_PREVIOUS):
 275                 font = h->metal;
 276                 break;
 277         case (DECO_ITALIC):
 278                 font = HTMLFONT_ITALIC;
 279                 break;
 280         case (DECO_BOLD):
 281                 font = HTMLFONT_BOLD;
 282                 break;
 283         case (DECO_ROMAN):
 284                 font = HTMLFONT_NONE;
 285                 break;
 286         default:
 287                 abort();
 288                 /* NOTREACHED */
 289         }
 290
 291         if (h->metaf) {
 292                 print_tagq(h, h->metaf);
 293                 h->metaf = NULL;
 294         }
 295
 296         h->metal = h->metac;
 297         h->metac = font;
 298
 299         if (HTMLFONT_NONE != font)
 300                 h->metaf = HTMLFONT_BOLD == font ?
 301                         print_otag(h, TAG_B, 0, NULL) :
 302                         print_otag(h, TAG_I, 0, NULL);
 303 }
 304
 305
 306 static int
 307 print_encode(struct html *h, const char *p, int norecurse)
 308 {
 309         size_t           sz;
 310         int              len, nospace;
 311         const char      *seq;
 312         enum roffdeco    deco;
 313         static const char rejs[6] = { '\\', '<', '>', '&', ASCII_HYPH, '\0' };
 314
 315         nospace = 0;
 316
 317         for (; *p; p++) {
 318                 sz = strcspn(p, rejs);
 319
 320                 fwrite(p, 1, sz, stdout);
 321                 p += /* LINTED */
 322                         sz;
 323
 324                 if ('<' == *p) {
 325                         printf("&lt;");
 326                         continue;
 327                 } else if ('>' == *p) {
 328                         printf("&gt;");
 329                         continue;
 330                 } else if ('&' == *p) {
 331                         printf("&amp;");
 332                         continue;
 333                 } else if (ASCII_HYPH == *p) {
 334                         /*
 335                          * Note: "soft hyphens" aren't graphically
 336                          * displayed when not breaking the text; we want
 337                          * them to be displayed.
 338                          */
 339                         /*printf("&#173;");*/
 340                         putchar('-');
 341                         continue;
 342                 } else if ('\0' == *p)
 343                         break;
 344
 345                 seq = ++p;
 346                 len = a2roffdeco(&deco, &seq, &sz);
 347
 348                 switch (deco) {
 349                 case (DECO_NUMBERED):
 350                         print_num(h, seq, sz);
 351                         break;
 352                 case (DECO_RESERVED):
 353                         print_res(h, seq, sz);
 354                         break;
 355                 case (DECO_SSPECIAL):
 356                         /* FALLTHROUGH */
 357                 case (DECO_SPECIAL):
 358                         print_spec(h, deco, seq, sz);
 359                         break;
 360                 case (DECO_PREVIOUS):
 361                         /* FALLTHROUGH */
 362                 case (DECO_BOLD):
 363                         /* FALLTHROUGH */
 364                 case (DECO_ITALIC):
 365                         /* FALLTHROUGH */
 366                 case (DECO_ROMAN):
 367                         if (norecurse)
 368                                 break;
 369                         print_metaf(h, deco);
 370                         break;
 371                 default:
 372                         break;
 373                 }
 374
 375                 p += len - 1;
 376
 377                 if (DECO_NOSPACE == deco && '\0' == *(p + 1))
 378                         nospace = 1;
 379         }
 380
 381         return(nospace);
 382 }
 383
 384
 385 static void
 386 print_attr(struct html *h, const char *key, const char *val)
 387 {
 388         printf(" %s=\"", key);
 389         (void)print_encode(h, val, 1);
 390         putchar('\"');
 391 }
 392
 393
 394 struct tag *
 395 print_otag(struct html *h, enum htmltag tag,
 396                 int sz, const struct htmlpair *p)
 397 {
 398         int              i;
 399         struct tag      *t;
 400
 401         /* Push this tags onto the stack of open scopes. */
 402
 403         if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 404                 t = malloc(sizeof(struct tag));
 405                 if (NULL == t) {
 406                         perror(NULL);
 407                         exit((int)MANDOCLEVEL_SYSERR);
 408                 }
 409                 t->tag = tag;
 410                 t->next = h->tags.head;
 411                 h->tags.head = t;
 412         } else
 413                 t = NULL;
 414
 415         if ( ! (HTML_NOSPACE & h->flags))
 416                 if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 417                         /* Manage keeps! */
 418                         if ( ! (HTML_KEEP & h->flags)) {
 419                                 if (HTML_PREKEEP & h->flags)
 420                                         h->flags |= HTML_KEEP;
 421                                 putchar(' ');
 422                         } else
 423                                 printf("&#160;");
 424                 }
 425
 426         if ( ! (h->flags & HTML_NONOSPACE))
 427                 h->flags &= ~HTML_NOSPACE;
 428         else
 429                 h->flags |= HTML_NOSPACE;
 430
 431         /* Print out the tag name and attributes. */
 432
 433         printf("<%s", htmltags[tag].name);
 434         for (i = 0; i < sz; i++)
 435                 print_attr(h, htmlattrs[p[i].key], p[i].val);
 436
 437         /* Add non-overridable attributes. */
 438
 439         if (TAG_HTML == tag && HTML_XHTML_1_0_STRICT == h->type) {
 440                 print_attr(h, "xmlns", "http://www.w3.org/1999/xhtml");
 441                 print_attr(h, "xml:lang", "en");
 442                 print_attr(h, "lang", "en");
 443         }
 444
 445         /* Accomodate for XML "well-formed" singleton escaping. */
 446
 447         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 448                 switch (h->type) {
 449                 case (HTML_XHTML_1_0_STRICT):
 450                         putchar('/');
 451                         break;
 452                 default:
 453                         break;
 454                 }
 455
 456         putchar('>');
 457
 458         h->flags |= HTML_NOSPACE;
 459
 460         if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
 461                 putchar('\n');
 462
 463         return(t);
 464 }
 465
 466
 467 static void
 468 print_ctag(struct html *h, enum htmltag tag)
 469 {
 470
 471         printf("</%s>", htmltags[tag].name);
 472         if (HTML_CLRLINE & htmltags[tag].flags) {
 473                 h->flags |= HTML_NOSPACE;
 474                 putchar('\n');
 475         }
 476 }
 477
 478
 479 void
 480 print_gen_decls(struct html *h)
 481 {
 482
 483         print_xmltype(h);
 484         print_doctype(h);
 485 }
 486
 487
 488 static void
 489 print_xmltype(struct html *h)
 490 {
 491
 492         if (HTML_XHTML_1_0_STRICT == h->type)
 493                 puts("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 494 }
 495
 496
 497 static void
 498 print_doctype(struct html *h)
 499 {
 500         const char      *doctype;
 501         const char      *dtd;
 502         const char      *name;
 503
 504         switch (h->type) {
 505         case (HTML_HTML_4_01_STRICT):
 506                 name = "HTML";
 507                 doctype = "-//W3C//DTD HTML 4.01//EN";
 508                 dtd = "http://www.w3.org/TR/html4/strict.dtd";
 509                 break;
 510         default:
 511                 name = "html";
 512                 doctype = "-//W3C//DTD XHTML 1.0 Strict//EN";
 513                 dtd = "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";
 514                 break;
 515         }
 516
 517         printf("<!DOCTYPE %s PUBLIC \"%s\" \"%s\">\n",
 518                         name, doctype, dtd);
 519 }
 520
 521
 522 void
 523 print_text(struct html *h, const char *word)
 524 {
 525
 526         if (word[0] && '\0' == word[1])
 527                 switch (word[0]) {
 528                 case('.'):
 529                         /* FALLTHROUGH */
 530                 case(','):
 531                         /* FALLTHROUGH */
 532                 case(';'):
 533                         /* FALLTHROUGH */
 534                 case(':'):
 535                         /* FALLTHROUGH */
 536                 case('?'):
 537                         /* FALLTHROUGH */
 538                 case('!'):
 539                         /* FALLTHROUGH */
 540                 case(')'):
 541                         /* FALLTHROUGH */
 542                 case(']'):
 543                         if ( ! (HTML_IGNDELIM & h->flags))
 544                                 h->flags |= HTML_NOSPACE;
 545                         break;
 546                 default:
 547                         break;
 548                 }
 549
 550         if ( ! (HTML_NOSPACE & h->flags)) {
 551                 /* Manage keeps! */
 552                 if ( ! (HTML_KEEP & h->flags)) {
 553                         if (HTML_PREKEEP & h->flags)
 554                                 h->flags |= HTML_KEEP;
 555                         putchar(' ');
 556                 } else
 557                         printf("&#160;");
 558         }
 559
 560         assert(NULL == h->metaf);
 561         if (HTMLFONT_NONE != h->metac)
 562                 h->metaf = HTMLFONT_BOLD == h->metac ?
 563                         print_otag(h, TAG_B, 0, NULL) :
 564                         print_otag(h, TAG_I, 0, NULL);
 565
 566         assert(word);
 567         if ( ! print_encode(h, word, 0))
 568                 if ( ! (h->flags & HTML_NONOSPACE))
 569                         h->flags &= ~HTML_NOSPACE;
 570
 571         if (h->metaf) {
 572                 print_tagq(h, h->metaf);
 573                 h->metaf = NULL;
 574         }
 575
 576         h->flags &= ~HTML_IGNDELIM;
 577
 578         /*
 579          * Note that we don't process the pipe: the parser sees it as
 580          * punctuation, but we don't in terms of typography.
 581          */
 582         if (word[0] && '\0' == word[1])
 583                 switch (word[0]) {
 584                 case('('):
 585                         /* FALLTHROUGH */
 586                 case('['):
 587                         h->flags |= HTML_NOSPACE;
 588                         break;
 589                 default:
 590                         break;
 591                 }
 592 }
 593
 594
 595 void
 596 print_tagq(struct html *h, const struct tag *until)
 597 {
 598         struct tag      *tag;
 599
 600         while ((tag = h->tags.head) != NULL) {
 601                 /*
 602                  * Remember to close out and nullify the current
 603                  * meta-font and table, if applicable.
 604                  */
 605                 if (tag == h->metaf)
 606                         h->metaf = NULL;
 607                 if (tag == h->tblt)
 608                         h->tblt = NULL;
 609                 print_ctag(h, tag->tag);
 610                 h->tags.head = tag->next;
 611                 free(tag);
 612                 if (until && tag == until)
 613                         return;
 614         }
 615 }
 616
 617
 618 void
 619 print_stagq(struct html *h, const struct tag *suntil)
 620 {
 621         struct tag      *tag;
 622
 623         while ((tag = h->tags.head) != NULL) {
 624                 if (suntil && tag == suntil)
 625                         return;
 626                 /*
 627                  * Remember to close out and nullify the current
 628                  * meta-font and table, if applicable.
 629                  */
 630                 if (tag == h->metaf)
 631                         h->metaf = NULL;
 632                 if (tag == h->tblt)
 633                         h->tblt = NULL;
 634                 print_ctag(h, tag->tag);
 635                 h->tags.head = tag->next;
 636                 free(tag);
 637         }
 638 }
 639
 640
 641 void
 642 bufinit(struct html *h)
 643 {
 644
 645         h->buf[0] = '\0';
 646         h->buflen = 0;
 647 }
 648
 649
 650 void
 651 bufcat_style(struct html *h, const char *key, const char *val)
 652 {
 653
 654         bufcat(h, key);
 655         bufncat(h, ":", 1);
 656         bufcat(h, val);
 657         bufncat(h, ";", 1);
 658 }
 659
 660
 661 void
 662 bufcat(struct html *h, const char *p)
 663 {
 664
 665         bufncat(h, p, strlen(p));
 666 }
 667
 668
 669 void
 670 buffmt(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
 682 void
 683 bufncat(struct html *h, const char *p, size_t sz)
 684 {
 685
 686         if (h->buflen + sz > BUFSIZ - 1)
 687                 sz = BUFSIZ - 1 - h->buflen;
 688
 689         (void)strncat(h->buf, p, sz);
 690         h->buflen += sz;
 691 }
 692
 693
 694 void
 695 buffmt_includes(struct html *h, const char *name)
 696 {
 697         const char      *p, *pp;
 698
 699         pp = h->base_includes;
 700
 701         while (NULL != (p = strchr(pp, '%'))) {
 702                 bufncat(h, pp, (size_t)(p - pp));
 703                 switch (*(p + 1)) {
 704                 case('I'):
 705                         bufcat(h, name);
 706                         break;
 707                 default:
 708                         bufncat(h, p, 2);
 709                         break;
 710                 }
 711                 pp = p + 2;
 712         }
 713         if (pp)
 714                 bufcat(h, pp);
 715 }
 716
 717
 718 void
 719 buffmt_man(struct html *h,
 720                 const char *name, const char *sec)
 721 {
 722         const char      *p, *pp;
 723
 724         pp = h->base_man;
 725
 726         /* LINTED */
 727         while (NULL != (p = strchr(pp, '%'))) {
 728                 bufncat(h, pp, (size_t)(p - pp));
 729                 switch (*(p + 1)) {
 730                 case('S'):
 731                         bufcat(h, sec ? sec : "1");
 732                         break;
 733                 case('N'):
 734                         buffmt(h, name);
 735                         break;
 736                 default:
 737                         bufncat(h, p, 2);
 738                         break;
 739                 }
 740                 pp = p + 2;
 741         }
 742         if (pp)
 743                 bufcat(h, pp);
 744 }
 745
 746
 747 void
 748 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 749 {
 750         double           v;
 751         const char      *u;
 752
 753         v = su->scale;
 754
 755         switch (su->unit) {
 756         case (SCALE_CM):
 757                 u = "cm";
 758                 break;
 759         case (SCALE_IN):
 760                 u = "in";
 761                 break;
 762         case (SCALE_PC):
 763                 u = "pc";
 764                 break;
 765         case (SCALE_PT):
 766                 u = "pt";
 767                 break;
 768         case (SCALE_EM):
 769                 u = "em";
 770                 break;
 771         case (SCALE_MM):
 772                 if (0 == (v /= 100))
 773                         v = 1;
 774                 u = "em";
 775                 break;
 776         case (SCALE_EN):
 777                 u = "ex";
 778                 break;
 779         case (SCALE_BU):
 780                 u = "ex";
 781                 break;
 782         case (SCALE_VS):
 783                 u = "em";
 784                 break;
 785         default:
 786                 u = "ex";
 787                 break;
 788         }
 789
 790         /*
 791          * XXX: the CSS spec isn't clear as to which types accept
 792          * integer or real numbers, so we just make them all decimals.
 793          */
 794         buffmt(h, "%s: %.2f%s;", p, v, u);
 795 }
 796
 797
 798 void
 799 html_idcat(char *dst, const char *src, int sz)
 800 {
 801         int              ssz;
 802
 803         assert(sz > 2);
 804
 805         /* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */
 806
 807         /* We can't start with a number (bah). */
 808
 809         if ('#' == *dst) {
 810                 dst++;
 811                 sz--;
 812         }
 813         if ('\0' == *dst) {
 814                 *dst++ = 'x';
 815                 *dst = '\0';
 816                 sz--;
 817         }
 818
 819         for ( ; *dst != '\0' && sz; dst++, sz--)
 820                 /* Jump to end. */ ;
 821
 822         for ( ; *src != '\0' && sz > 1; src++) {
 823                 ssz = snprintf(dst, (size_t)sz, "%.2x", *src);
 824                 sz -= ssz;
 825                 dst += ssz;
 826         }
 827 }