html.c

   1 /*      $Id: html.c,v 1.129 2011/03/17 09:16:38 kristaps 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 = mandoc_calloc(1, sizeof(struct html));
 124
 125         h->type = type;
 126         h->tags.head = NULL;
 127         h->symtab = chars_init(CHARS_HTML);
 128
 129         while (outopts && *outopts)
 130                 switch (getsubopt(&outopts, UNCONST(toks), &v)) {
 131                 case (0):
 132                         h->style = v;
 133                         break;
 134                 case (1):
 135                         h->base_man = v;
 136                         break;
 137                 case (2):
 138                         h->base_includes = v;
 139                         break;
 140                 default:
 141                         break;
 142                 }
 143
 144         return(h);
 145 }
 146
 147 void *
 148 html_alloc(char *outopts)
 149 {
 150
 151         return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
 152 }
 153
 154
 155 void *
 156 xhtml_alloc(char *outopts)
 157 {
 158
 159         return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
 160 }
 161
 162
 163 void
 164 html_free(void *p)
 165 {
 166         struct tag      *tag;
 167         struct html     *h;
 168
 169         h = (struct html *)p;
 170
 171         while ((tag = h->tags.head) != NULL) {
 172                 h->tags.head = tag->next;
 173                 free(tag);
 174         }
 175
 176         if (h->symtab)
 177                 chars_free(h->symtab);
 178
 179         free(h);
 180 }
 181
 182
 183 void
 184 print_gen_head(struct html *h)
 185 {
 186         struct htmlpair  tag[4];
 187
 188         tag[0].key = ATTR_HTTPEQUIV;
 189         tag[0].val = "Content-Type";
 190         tag[1].key = ATTR_CONTENT;
 191         tag[1].val = "text/html; charset=utf-8";
 192         print_otag(h, TAG_META, 2, tag);
 193
 194         tag[0].key = ATTR_NAME;
 195         tag[0].val = "resource-type";
 196         tag[1].key = ATTR_CONTENT;
 197         tag[1].val = "document";
 198         print_otag(h, TAG_META, 2, tag);
 199
 200         if (h->style) {
 201                 tag[0].key = ATTR_REL;
 202                 tag[0].val = "stylesheet";
 203                 tag[1].key = ATTR_HREF;
 204                 tag[1].val = h->style;
 205                 tag[2].key = ATTR_TYPE;
 206                 tag[2].val = "text/css";
 207                 tag[3].key = ATTR_MEDIA;
 208                 tag[3].val = "all";
 209                 print_otag(h, TAG_LINK, 4, tag);
 210         }
 211 }
 212
 213 /* ARGSUSED */
 214 static void
 215 print_num(struct html *h, const char *p, size_t len)
 216 {
 217         const char      *rhs;
 218
 219         rhs = chars_num2char(p, len);
 220         if (rhs)
 221                 putchar((int)*rhs);
 222 }
 223
 224 static void
 225 print_spec(struct html *h, enum roffdeco d, const char *p, size_t len)
 226 {
 227         int              cp;
 228         const char      *rhs;
 229         size_t           sz;
 230
 231         if ((cp = chars_spec2cp(h->symtab, p, len)) > 0) {
 232                 printf("&#%d;", cp);
 233                 return;
 234         } else if (-1 == cp && DECO_SSPECIAL == d) {
 235                 fwrite(p, 1, len, stdout);
 236                 return;
 237         } else if (-1 == cp)
 238                 return;
 239
 240         if (NULL != (rhs = chars_spec2str(h->symtab, p, len, &sz)))
 241                 fwrite(rhs, 1, sz, stdout);
 242 }
 243
 244
 245 static void
 246 print_res(struct html *h, const char *p, size_t len)
 247 {
 248         int              cp;
 249         const char      *rhs;
 250         size_t           sz;
 251
 252         if ((cp = chars_res2cp(h->symtab, p, len)) > 0) {
 253                 printf("&#%d;", cp);
 254                 return;
 255         } else if (-1 == cp)
 256                 return;
 257
 258         if (NULL != (rhs = chars_res2str(h->symtab, p, len, &sz)))
 259                 fwrite(rhs, 1, sz, stdout);
 260 }
 261
 262
 263 static void
 264 print_metaf(struct html *h, enum roffdeco deco)
 265 {
 266         enum htmlfont    font;
 267
 268         switch (deco) {
 269         case (DECO_PREVIOUS):
 270                 font = h->metal;
 271                 break;
 272         case (DECO_ITALIC):
 273                 font = HTMLFONT_ITALIC;
 274                 break;
 275         case (DECO_BOLD):
 276                 font = HTMLFONT_BOLD;
 277                 break;
 278         case (DECO_ROMAN):
 279                 font = HTMLFONT_NONE;
 280                 break;
 281         default:
 282                 abort();
 283                 /* NOTREACHED */
 284         }
 285
 286         if (h->metaf) {
 287                 print_tagq(h, h->metaf);
 288                 h->metaf = NULL;
 289         }
 290
 291         h->metal = h->metac;
 292         h->metac = font;
 293
 294         if (HTMLFONT_NONE != font)
 295                 h->metaf = HTMLFONT_BOLD == font ?
 296                         print_otag(h, TAG_B, 0, NULL) :
 297                         print_otag(h, TAG_I, 0, NULL);
 298 }
 299
 300
 301 static int
 302 print_encode(struct html *h, const char *p, int norecurse)
 303 {
 304         size_t           sz;
 305         int              len, nospace;
 306         const char      *seq;
 307         enum roffdeco    deco;
 308         static const char rejs[6] = { '\\', '<', '>', '&', ASCII_HYPH, '\0' };
 309
 310         nospace = 0;
 311
 312         for (; *p; p++) {
 313                 sz = strcspn(p, rejs);
 314
 315                 fwrite(p, 1, sz, stdout);
 316                 p += /* LINTED */
 317                         sz;
 318
 319                 if ('<' == *p) {
 320                         printf("&lt;");
 321                         continue;
 322                 } else if ('>' == *p) {
 323                         printf("&gt;");
 324                         continue;
 325                 } else if ('&' == *p) {
 326                         printf("&amp;");
 327                         continue;
 328                 } else if (ASCII_HYPH == *p) {
 329                         /*
 330                          * Note: "soft hyphens" aren't graphically
 331                          * displayed when not breaking the text; we want
 332                          * them to be displayed.
 333                          */
 334                         /*printf("&#173;");*/
 335                         putchar('-');
 336                         continue;
 337                 } else if ('\0' == *p)
 338                         break;
 339
 340                 seq = ++p;
 341                 len = a2roffdeco(&deco, &seq, &sz);
 342
 343                 switch (deco) {
 344                 case (DECO_NUMBERED):
 345                         print_num(h, seq, sz);
 346                         break;
 347                 case (DECO_RESERVED):
 348                         print_res(h, seq, sz);
 349                         break;
 350                 case (DECO_SSPECIAL):
 351                         /* FALLTHROUGH */
 352                 case (DECO_SPECIAL):
 353                         print_spec(h, deco, seq, sz);
 354                         break;
 355                 case (DECO_PREVIOUS):
 356                         /* FALLTHROUGH */
 357                 case (DECO_BOLD):
 358                         /* FALLTHROUGH */
 359                 case (DECO_ITALIC):
 360                         /* FALLTHROUGH */
 361                 case (DECO_ROMAN):
 362                         if (norecurse)
 363                                 break;
 364                         print_metaf(h, deco);
 365                         break;
 366                 default:
 367                         break;
 368                 }
 369
 370                 p += len - 1;
 371
 372                 if (DECO_NOSPACE == deco && '\0' == *(p + 1))
 373                         nospace = 1;
 374         }
 375
 376         return(nospace);
 377 }
 378
 379
 380 static void
 381 print_attr(struct html *h, const char *key, const char *val)
 382 {
 383         printf(" %s=\"", key);
 384         (void)print_encode(h, val, 1);
 385         putchar('\"');
 386 }
 387
 388
 389 struct tag *
 390 print_otag(struct html *h, enum htmltag tag,
 391                 int sz, const struct htmlpair *p)
 392 {
 393         int              i;
 394         struct tag      *t;
 395
 396         /* Push this tags onto the stack of open scopes. */
 397
 398         if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 399                 t = mandoc_malloc(sizeof(struct tag));
 400                 t->tag = tag;
 401                 t->next = h->tags.head;
 402                 h->tags.head = t;
 403         } else
 404                 t = NULL;
 405
 406         if ( ! (HTML_NOSPACE & h->flags))
 407                 if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 408                         /* Manage keeps! */
 409                         if ( ! (HTML_KEEP & h->flags)) {
 410                                 if (HTML_PREKEEP & h->flags)
 411                                         h->flags |= HTML_KEEP;
 412                                 putchar(' ');
 413                         } else
 414                                 printf("&#160;");
 415                 }
 416
 417         if ( ! (h->flags & HTML_NONOSPACE))
 418                 h->flags &= ~HTML_NOSPACE;
 419         else
 420                 h->flags |= HTML_NOSPACE;
 421
 422         /* Print out the tag name and attributes. */
 423
 424         printf("<%s", htmltags[tag].name);
 425         for (i = 0; i < sz; i++)
 426                 print_attr(h, htmlattrs[p[i].key], p[i].val);
 427
 428         /* Add non-overridable attributes. */
 429
 430         if (TAG_HTML == tag && HTML_XHTML_1_0_STRICT == h->type) {
 431                 print_attr(h, "xmlns", "http://www.w3.org/1999/xhtml");
 432                 print_attr(h, "xml:lang", "en");
 433                 print_attr(h, "lang", "en");
 434         }
 435
 436         /* Accomodate for XML "well-formed" singleton escaping. */
 437
 438         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 439                 switch (h->type) {
 440                 case (HTML_XHTML_1_0_STRICT):
 441                         putchar('/');
 442                         break;
 443                 default:
 444                         break;
 445                 }
 446
 447         putchar('>');
 448
 449         h->flags |= HTML_NOSPACE;
 450
 451         if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
 452                 putchar('\n');
 453
 454         return(t);
 455 }
 456
 457
 458 static void
 459 print_ctag(struct html *h, enum htmltag tag)
 460 {
 461
 462         printf("</%s>", htmltags[tag].name);
 463         if (HTML_CLRLINE & htmltags[tag].flags) {
 464                 h->flags |= HTML_NOSPACE;
 465                 putchar('\n');
 466         }
 467 }
 468
 469
 470 void
 471 print_gen_decls(struct html *h)
 472 {
 473
 474         print_xmltype(h);
 475         print_doctype(h);
 476 }
 477
 478
 479 static void
 480 print_xmltype(struct html *h)
 481 {
 482
 483         if (HTML_XHTML_1_0_STRICT == h->type)
 484                 puts("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 485 }
 486
 487
 488 static void
 489 print_doctype(struct html *h)
 490 {
 491         const char      *doctype;
 492         const char      *dtd;
 493         const char      *name;
 494
 495         switch (h->type) {
 496         case (HTML_HTML_4_01_STRICT):
 497                 name = "HTML";
 498                 doctype = "-//W3C//DTD HTML 4.01//EN";
 499                 dtd = "http://www.w3.org/TR/html4/strict.dtd";
 500                 break;
 501         default:
 502                 name = "html";
 503                 doctype = "-//W3C//DTD XHTML 1.0 Strict//EN";
 504                 dtd = "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";
 505                 break;
 506         }
 507
 508         printf("<!DOCTYPE %s PUBLIC \"%s\" \"%s\">\n",
 509                         name, doctype, dtd);
 510 }
 511
 512
 513 void
 514 print_text(struct html *h, const char *word)
 515 {
 516
 517         if (DELIM_CLOSE == mandoc_isdelim(word))
 518                 if ( ! (HTML_IGNDELIM & h->flags))
 519                         h->flags |= HTML_NOSPACE;
 520
 521         if ( ! (HTML_NOSPACE & h->flags)) {
 522                 /* Manage keeps! */
 523                 if ( ! (HTML_KEEP & h->flags)) {
 524                         if (HTML_PREKEEP & h->flags)
 525                                 h->flags |= HTML_KEEP;
 526                         putchar(' ');
 527                 } else
 528                         printf("&#160;");
 529         }
 530
 531         assert(NULL == h->metaf);
 532         if (HTMLFONT_NONE != h->metac)
 533                 h->metaf = HTMLFONT_BOLD == h->metac ?
 534                         print_otag(h, TAG_B, 0, NULL) :
 535                         print_otag(h, TAG_I, 0, NULL);
 536
 537         assert(word);
 538         if ( ! print_encode(h, word, 0))
 539                 if ( ! (h->flags & HTML_NONOSPACE))
 540                         h->flags &= ~HTML_NOSPACE;
 541
 542         if (h->metaf) {
 543                 print_tagq(h, h->metaf);
 544                 h->metaf = NULL;
 545         }
 546
 547         h->flags &= ~HTML_IGNDELIM;
 548
 549         if (DELIM_OPEN == mandoc_isdelim(word))
 550                 h->flags |= HTML_NOSPACE;
 551 }
 552
 553
 554 void
 555 print_tagq(struct html *h, const struct tag *until)
 556 {
 557         struct tag      *tag;
 558
 559         while ((tag = h->tags.head) != NULL) {
 560                 /*
 561                  * Remember to close out and nullify the current
 562                  * meta-font and table, if applicable.
 563                  */
 564                 if (tag == h->metaf)
 565                         h->metaf = NULL;
 566                 if (tag == h->tblt)
 567                         h->tblt = NULL;
 568                 print_ctag(h, tag->tag);
 569                 h->tags.head = tag->next;
 570                 free(tag);
 571                 if (until && tag == until)
 572                         return;
 573         }
 574 }
 575
 576
 577 void
 578 print_stagq(struct html *h, const struct tag *suntil)
 579 {
 580         struct tag      *tag;
 581
 582         while ((tag = h->tags.head) != NULL) {
 583                 if (suntil && tag == suntil)
 584                         return;
 585                 /*
 586                  * Remember to close out and nullify the current
 587                  * meta-font and table, if applicable.
 588                  */
 589                 if (tag == h->metaf)
 590                         h->metaf = NULL;
 591                 if (tag == h->tblt)
 592                         h->tblt = NULL;
 593                 print_ctag(h, tag->tag);
 594                 h->tags.head = tag->next;
 595                 free(tag);
 596         }
 597 }
 598
 599
 600 void
 601 bufinit(struct html *h)
 602 {
 603
 604         h->buf[0] = '\0';
 605         h->buflen = 0;
 606 }
 607
 608
 609 void
 610 bufcat_style(struct html *h, const char *key, const char *val)
 611 {
 612
 613         bufcat(h, key);
 614         bufncat(h, ":", 1);
 615         bufcat(h, val);
 616         bufncat(h, ";", 1);
 617 }
 618
 619
 620 void
 621 bufcat(struct html *h, const char *p)
 622 {
 623
 624         bufncat(h, p, strlen(p));
 625 }
 626
 627
 628 void
 629 buffmt(struct html *h, const char *fmt, ...)
 630 {
 631         va_list          ap;
 632
 633         va_start(ap, fmt);
 634         (void)vsnprintf(h->buf + (int)h->buflen,
 635                         BUFSIZ - h->buflen - 1, fmt, ap);
 636         va_end(ap);
 637         h->buflen = strlen(h->buf);
 638 }
 639
 640
 641 void
 642 bufncat(struct html *h, const char *p, size_t sz)
 643 {
 644
 645         if (h->buflen + sz > BUFSIZ - 1)
 646                 sz = BUFSIZ - 1 - h->buflen;
 647
 648         (void)strncat(h->buf, p, sz);
 649         h->buflen += sz;
 650 }
 651
 652
 653 void
 654 buffmt_includes(struct html *h, const char *name)
 655 {
 656         const char      *p, *pp;
 657
 658         pp = h->base_includes;
 659
 660         while (NULL != (p = strchr(pp, '%'))) {
 661                 bufncat(h, pp, (size_t)(p - pp));
 662                 switch (*(p + 1)) {
 663                 case('I'):
 664                         bufcat(h, name);
 665                         break;
 666                 default:
 667                         bufncat(h, p, 2);
 668                         break;
 669                 }
 670                 pp = p + 2;
 671         }
 672         if (pp)
 673                 bufcat(h, pp);
 674 }
 675
 676
 677 void
 678 buffmt_man(struct html *h,
 679                 const char *name, const char *sec)
 680 {
 681         const char      *p, *pp;
 682
 683         pp = h->base_man;
 684
 685         /* LINTED */
 686         while (NULL != (p = strchr(pp, '%'))) {
 687                 bufncat(h, pp, (size_t)(p - pp));
 688                 switch (*(p + 1)) {
 689                 case('S'):
 690                         bufcat(h, sec ? sec : "1");
 691                         break;
 692                 case('N'):
 693                         buffmt(h, name);
 694                         break;
 695                 default:
 696                         bufncat(h, p, 2);
 697                         break;
 698                 }
 699                 pp = p + 2;
 700         }
 701         if (pp)
 702                 bufcat(h, pp);
 703 }
 704
 705
 706 void
 707 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 708 {
 709         double           v;
 710         const char      *u;
 711
 712         v = su->scale;
 713
 714         switch (su->unit) {
 715         case (SCALE_CM):
 716                 u = "cm";
 717                 break;
 718         case (SCALE_IN):
 719                 u = "in";
 720                 break;
 721         case (SCALE_PC):
 722                 u = "pc";
 723                 break;
 724         case (SCALE_PT):
 725                 u = "pt";
 726                 break;
 727         case (SCALE_EM):
 728                 u = "em";
 729                 break;
 730         case (SCALE_MM):
 731                 if (0 == (v /= 100))
 732                         v = 1;
 733                 u = "em";
 734                 break;
 735         case (SCALE_EN):
 736                 u = "ex";
 737                 break;
 738         case (SCALE_BU):
 739                 u = "ex";
 740                 break;
 741         case (SCALE_VS):
 742                 u = "em";
 743                 break;
 744         default:
 745                 u = "ex";
 746                 break;
 747         }
 748
 749         /*
 750          * XXX: the CSS spec isn't clear as to which types accept
 751          * integer or real numbers, so we just make them all decimals.
 752          */
 753         buffmt(h, "%s: %.2f%s;", p, v, u);
 754 }
 755
 756
 757 void
 758 html_idcat(char *dst, const char *src, int sz)
 759 {
 760         int              ssz;
 761
 762         assert(sz > 2);
 763
 764         /* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */
 765
 766         /* We can't start with a number (bah). */
 767
 768         if ('#' == *dst) {
 769                 dst++;
 770                 sz--;
 771         }
 772         if ('\0' == *dst) {
 773                 *dst++ = 'x';
 774                 *dst = '\0';
 775                 sz--;
 776         }
 777
 778         for ( ; *dst != '\0' && sz; dst++, sz--)
 779                 /* Jump to end. */ ;
 780
 781         for ( ; *src != '\0' && sz > 1; src++) {
 782                 ssz = snprintf(dst, (size_t)sz, "%.2x", *src);
 783                 sz -= ssz;
 784                 dst += ssz;
 785         }
 786 }