html.c

   1 /*      $Id: html.c,v 1.115 2010/12/15 15:59:23 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <sys/types.h>
  22
  23 #include <assert.h>
  24 #include <ctype.h>
  25 #include <stdarg.h>
  26 #include <stdio.h>
  27 #include <stdint.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <unistd.h>
  31
  32 #include "mandoc.h"
  33 #include "out.h"
  34 #include "chars.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 };
  72
  73 static  const char      *const htmlfonts[HTMLFONT_MAX] = {
  74         "roman",
  75         "bold",
  76         "italic"
  77 };
  78
  79 static  const char      *const htmlattrs[ATTR_MAX] = {
  80         "http-equiv",
  81         "content",
  82         "name",
  83         "rel",
  84         "href",
  85         "type",
  86         "media",
  87         "class",
  88         "style",
  89         "width",
  90         "valign",
  91         "target",
  92         "id",
  93         "summary",
  94 };
  95
  96 static  void              print_spec(struct html *, enum roffdeco,
  97                                 const char *, size_t);
  98 static  void              print_res(struct html *, const char *, size_t);
  99 static  void              print_ctag(struct html *, enum htmltag);
 100 static  void              print_doctype(struct html *);
 101 static  void              print_xmltype(struct html *);
 102 static  int               print_encode(struct html *, const char *, int);
 103 static  void              print_metaf(struct html *, enum roffdeco);
 104 static  void              print_attr(struct html *,
 105                                 const char *, const char *);
 106 static  void             *ml_alloc(char *, enum htmltype);
 107
 108
 109 static void *
 110 ml_alloc(char *outopts, enum htmltype type)
 111 {
 112         struct html     *h;
 113         const char      *toks[4];
 114         char            *v;
 115
 116         toks[0] = "style";
 117         toks[1] = "man";
 118         toks[2] = "includes";
 119         toks[3] = NULL;
 120
 121         h = calloc(1, sizeof(struct html));
 122         if (NULL == h) {
 123                 perror(NULL);
 124                 exit((int)MANDOCLEVEL_SYSERR);
 125         }
 126
 127         h->type = type;
 128         h->tags.head = NULL;
 129         h->symtab = chars_init(CHARS_HTML);
 130
 131         while (outopts && *outopts)
 132                 switch (getsubopt(&outopts, UNCONST(toks), &v)) {
 133                 case (0):
 134                         h->style = v;
 135                         break;
 136                 case (1):
 137                         h->base_man = v;
 138                         break;
 139                 case (2):
 140                         h->base_includes = v;
 141                         break;
 142                 default:
 143                         break;
 144                 }
 145
 146         return(h);
 147 }
 148
 149 void *
 150 html_alloc(char *outopts)
 151 {
 152
 153         return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
 154 }
 155
 156
 157 void *
 158 xhtml_alloc(char *outopts)
 159 {
 160
 161         return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
 162 }
 163
 164
 165 void
 166 html_free(void *p)
 167 {
 168         struct tag      *tag;
 169         struct html     *h;
 170
 171         h = (struct html *)p;
 172
 173         while ((tag = h->tags.head) != NULL) {
 174                 h->tags.head = tag->next;
 175                 free(tag);
 176         }
 177
 178         if (h->symtab)
 179                 chars_free(h->symtab);
 180
 181         free(h);
 182 }
 183
 184
 185 void
 186 print_gen_head(struct html *h)
 187 {
 188         struct htmlpair  tag[4];
 189
 190         tag[0].key = ATTR_HTTPEQUIV;
 191         tag[0].val = "Content-Type";
 192         tag[1].key = ATTR_CONTENT;
 193         tag[1].val = "text/html; charset=utf-8";
 194         print_otag(h, TAG_META, 2, tag);
 195
 196         tag[0].key = ATTR_NAME;
 197         tag[0].val = "resource-type";
 198         tag[1].key = ATTR_CONTENT;
 199         tag[1].val = "document";
 200         print_otag(h, TAG_META, 2, tag);
 201
 202         if (h->style) {
 203                 tag[0].key = ATTR_REL;
 204                 tag[0].val = "stylesheet";
 205                 tag[1].key = ATTR_HREF;
 206                 tag[1].val = h->style;
 207                 tag[2].key = ATTR_TYPE;
 208                 tag[2].val = "text/css";
 209                 tag[3].key = ATTR_MEDIA;
 210                 tag[3].val = "all";
 211                 print_otag(h, TAG_LINK, 4, tag);
 212         }
 213 }
 214
 215
 216 static void
 217 print_spec(struct html *h, enum roffdeco d, const char *p, size_t len)
 218 {
 219         int              cp;
 220         const char      *rhs;
 221         size_t           sz;
 222
 223         if ((cp = chars_spec2cp(h->symtab, p, len)) > 0) {
 224                 printf("&#%d;", cp);
 225                 return;
 226         } else if (-1 == cp && DECO_SSPECIAL == d) {
 227                 fwrite(p, 1, len, stdout);
 228                 return;
 229         } else if (-1 == cp)
 230                 return;
 231
 232         if (NULL != (rhs = chars_spec2str(h->symtab, p, len, &sz)))
 233                 fwrite(rhs, 1, sz, stdout);
 234 }
 235
 236
 237 static void
 238 print_res(struct html *h, const char *p, size_t len)
 239 {
 240         int              cp;
 241         const char      *rhs;
 242         size_t           sz;
 243
 244         if ((cp = chars_res2cp(h->symtab, p, len)) > 0) {
 245                 printf("&#%d;", cp);
 246                 return;
 247         } else if (-1 == cp)
 248                 return;
 249
 250         if (NULL != (rhs = chars_res2str(h->symtab, p, len, &sz)))
 251                 fwrite(rhs, 1, sz, stdout);
 252 }
 253
 254
 255 struct tag *
 256 print_ofont(struct html *h, enum htmlfont font)
 257 {
 258         struct htmlpair  tag;
 259
 260         h->metal = h->metac;
 261         h->metac = font;
 262
 263         /* FIXME: DECO_ROMAN should just close out preexisting. */
 264
 265         if (h->metaf && h->tags.head == h->metaf)
 266                 print_tagq(h, h->metaf);
 267
 268         PAIR_CLASS_INIT(&tag, htmlfonts[font]);
 269         h->metaf = print_otag(h, TAG_SPAN, 1, &tag);
 270         return(h->metaf);
 271 }
 272
 273
 274 static void
 275 print_metaf(struct html *h, enum roffdeco deco)
 276 {
 277         enum htmlfont    font;
 278
 279         switch (deco) {
 280         case (DECO_PREVIOUS):
 281                 font = h->metal;
 282                 break;
 283         case (DECO_ITALIC):
 284                 font = HTMLFONT_ITALIC;
 285                 break;
 286         case (DECO_BOLD):
 287                 font = HTMLFONT_BOLD;
 288                 break;
 289         case (DECO_ROMAN):
 290                 font = HTMLFONT_NONE;
 291                 break;
 292         default:
 293                 abort();
 294                 /* NOTREACHED */
 295         }
 296
 297         (void)print_ofont(h, font);
 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_RESERVED):
 345                         print_res(h, seq, sz);
 346                         break;
 347                 case (DECO_SSPECIAL):
 348                         /* FALLTHROUGH */
 349                 case (DECO_SPECIAL):
 350                         print_spec(h, deco, seq, sz);
 351                         break;
 352                 case (DECO_PREVIOUS):
 353                         /* FALLTHROUGH */
 354                 case (DECO_BOLD):
 355                         /* FALLTHROUGH */
 356                 case (DECO_ITALIC):
 357                         /* FALLTHROUGH */
 358                 case (DECO_ROMAN):
 359                         if (norecurse)
 360                                 break;
 361                         print_metaf(h, deco);
 362                         break;
 363                 default:
 364                         break;
 365                 }
 366
 367                 p += len - 1;
 368
 369                 if (DECO_NOSPACE == deco && '\0' == *(p + 1))
 370                         nospace = 1;
 371         }
 372
 373         return(nospace);
 374 }
 375
 376
 377 static void
 378 print_attr(struct html *h, const char *key, const char *val)
 379 {
 380         printf(" %s=\"", key);
 381         (void)print_encode(h, val, 1);
 382         putchar('\"');
 383 }
 384
 385
 386 struct tag *
 387 print_otag(struct html *h, enum htmltag tag,
 388                 int sz, const struct htmlpair *p)
 389 {
 390         int              i;
 391         struct tag      *t;
 392
 393         /* Push this tags onto the stack of open scopes. */
 394
 395         if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 396                 t = malloc(sizeof(struct tag));
 397                 if (NULL == t) {
 398                         perror(NULL);
 399                         exit((int)MANDOCLEVEL_SYSERR);
 400                 }
 401                 t->tag = tag;
 402                 t->next = h->tags.head;
 403                 h->tags.head = t;
 404         } else
 405                 t = NULL;
 406
 407         if ( ! (HTML_NOSPACE & h->flags))
 408                 if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 409                         /* Manage keeps! */
 410                         if ( ! (HTML_KEEP & h->flags)) {
 411                                 if (HTML_PREKEEP & h->flags)
 412                                         h->flags |= HTML_KEEP;
 413                                 putchar(' ');
 414                         } else
 415                                 printf("&#160;");
 416                 }
 417
 418         if ( ! (h->flags & HTML_NONOSPACE))
 419                 h->flags &= ~HTML_NOSPACE;
 420         else
 421                 h->flags |= HTML_NOSPACE;
 422
 423         /* Print out the tag name and attributes. */
 424
 425         printf("<%s", htmltags[tag].name);
 426         for (i = 0; i < sz; i++)
 427                 print_attr(h, htmlattrs[p[i].key], p[i].val);
 428
 429         /* Add non-overridable attributes. */
 430
 431         if (TAG_HTML == tag && HTML_XHTML_1_0_STRICT == h->type) {
 432                 print_attr(h, "xmlns", "http://www.w3.org/1999/xhtml");
 433                 print_attr(h, "xml:lang", "en");
 434                 print_attr(h, "lang", "en");
 435         }
 436
 437         /* Accomodate for XML "well-formed" singleton escaping. */
 438
 439         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 440                 switch (h->type) {
 441                 case (HTML_XHTML_1_0_STRICT):
 442                         putchar('/');
 443                         break;
 444                 default:
 445                         break;
 446                 }
 447
 448         putchar('>');
 449
 450         h->flags |= HTML_NOSPACE;
 451         return(t);
 452 }
 453
 454
 455 static void
 456 print_ctag(struct html *h, enum htmltag tag)
 457 {
 458
 459         printf("</%s>", htmltags[tag].name);
 460         if (HTML_CLRLINE & htmltags[tag].flags) {
 461                 h->flags |= HTML_NOSPACE;
 462                 putchar('\n');
 463         }
 464 }
 465
 466
 467 void
 468 print_gen_decls(struct html *h)
 469 {
 470
 471         print_xmltype(h);
 472         print_doctype(h);
 473 }
 474
 475
 476 static void
 477 print_xmltype(struct html *h)
 478 {
 479
 480         if (HTML_XHTML_1_0_STRICT == h->type)
 481                 printf("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 482 }
 483
 484
 485 static void
 486 print_doctype(struct html *h)
 487 {
 488         const char      *doctype;
 489         const char      *dtd;
 490         const char      *name;
 491
 492         switch (h->type) {
 493         case (HTML_HTML_4_01_STRICT):
 494                 name = "HTML";
 495                 doctype = "-//W3C//DTD HTML 4.01//EN";
 496                 dtd = "http://www.w3.org/TR/html4/strict.dtd";
 497                 break;
 498         default:
 499                 name = "html";
 500                 doctype = "-//W3C//DTD XHTML 1.0 Strict//EN";
 501                 dtd = "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";
 502                 break;
 503         }
 504
 505         printf("<!DOCTYPE %s PUBLIC \"%s\" \"%s\">\n",
 506                         name, doctype, dtd);
 507 }
 508
 509
 510 void
 511 print_text(struct html *h, const char *word)
 512 {
 513
 514         if (word[0] && '\0' == word[1])
 515                 switch (word[0]) {
 516                 case('.'):
 517                         /* FALLTHROUGH */
 518                 case(','):
 519                         /* FALLTHROUGH */
 520                 case(';'):
 521                         /* FALLTHROUGH */
 522                 case(':'):
 523                         /* FALLTHROUGH */
 524                 case('?'):
 525                         /* FALLTHROUGH */
 526                 case('!'):
 527                         /* FALLTHROUGH */
 528                 case(')'):
 529                         /* FALLTHROUGH */
 530                 case(']'):
 531                         if ( ! (HTML_IGNDELIM & h->flags))
 532                                 h->flags |= HTML_NOSPACE;
 533                         break;
 534                 default:
 535                         break;
 536                 }
 537
 538         if ( ! (HTML_NOSPACE & h->flags)) {
 539                 /* Manage keeps! */
 540                 if ( ! (HTML_KEEP & h->flags)) {
 541                         if (HTML_PREKEEP & h->flags)
 542                                 h->flags |= HTML_KEEP;
 543                         putchar(' ');
 544                 } else
 545                         printf("&#160;");
 546         }
 547
 548         assert(word);
 549         if ( ! print_encode(h, word, 0))
 550                 if ( ! (h->flags & HTML_NONOSPACE))
 551                         h->flags &= ~HTML_NOSPACE;
 552
 553         h->flags &= ~HTML_IGNDELIM;
 554
 555         /*
 556          * Note that we don't process the pipe: the parser sees it as
 557          * punctuation, but we don't in terms of typography.
 558          */
 559         if (word[0] && '\0' == word[1])
 560                 switch (word[0]) {
 561                 case('('):
 562                         /* FALLTHROUGH */
 563                 case('['):
 564                         h->flags |= HTML_NOSPACE;
 565                         break;
 566                 default:
 567                         break;
 568                 }
 569 }
 570
 571
 572 void
 573 print_tagq(struct html *h, const struct tag *until)
 574 {
 575         struct tag      *tag;
 576
 577         while ((tag = h->tags.head) != NULL) {
 578                 if (tag == h->metaf)
 579                         h->metaf = NULL;
 580                 print_ctag(h, tag->tag);
 581                 h->tags.head = tag->next;
 582                 free(tag);
 583                 if (until && tag == until)
 584                         return;
 585         }
 586 }
 587
 588
 589 void
 590 print_stagq(struct html *h, const struct tag *suntil)
 591 {
 592         struct tag      *tag;
 593
 594         while ((tag = h->tags.head) != NULL) {
 595                 if (suntil && tag == suntil)
 596                         return;
 597                 if (tag == h->metaf)
 598                         h->metaf = NULL;
 599                 print_ctag(h, tag->tag);
 600                 h->tags.head = tag->next;
 601                 free(tag);
 602         }
 603 }
 604
 605
 606 void
 607 bufinit(struct html *h)
 608 {
 609
 610         h->buf[0] = '\0';
 611         h->buflen = 0;
 612 }
 613
 614
 615 void
 616 bufcat_style(struct html *h, const char *key, const char *val)
 617 {
 618
 619         bufcat(h, key);
 620         bufncat(h, ":", 1);
 621         bufcat(h, val);
 622         bufncat(h, ";", 1);
 623 }
 624
 625
 626 void
 627 bufcat(struct html *h, const char *p)
 628 {
 629
 630         bufncat(h, p, strlen(p));
 631 }
 632
 633
 634 void
 635 buffmt(struct html *h, const char *fmt, ...)
 636 {
 637         va_list          ap;
 638
 639         va_start(ap, fmt);
 640         (void)vsnprintf(h->buf + (int)h->buflen,
 641                         BUFSIZ - h->buflen - 1, fmt, ap);
 642         va_end(ap);
 643         h->buflen = strlen(h->buf);
 644 }
 645
 646
 647 void
 648 bufncat(struct html *h, const char *p, size_t sz)
 649 {
 650
 651         if (h->buflen + sz > BUFSIZ - 1)
 652                 sz = BUFSIZ - 1 - h->buflen;
 653
 654         (void)strncat(h->buf, p, sz);
 655         h->buflen += sz;
 656 }
 657
 658
 659 void
 660 buffmt_includes(struct html *h, const char *name)
 661 {
 662         const char      *p, *pp;
 663
 664         pp = h->base_includes;
 665
 666         while (NULL != (p = strchr(pp, '%'))) {
 667                 bufncat(h, pp, (size_t)(p - pp));
 668                 switch (*(p + 1)) {
 669                 case('I'):
 670                         bufcat(h, name);
 671                         break;
 672                 default:
 673                         bufncat(h, p, 2);
 674                         break;
 675                 }
 676                 pp = p + 2;
 677         }
 678         if (pp)
 679                 bufcat(h, pp);
 680 }
 681
 682
 683 void
 684 buffmt_man(struct html *h,
 685                 const char *name, const char *sec)
 686 {
 687         const char      *p, *pp;
 688
 689         pp = h->base_man;
 690
 691         /* LINTED */
 692         while (NULL != (p = strchr(pp, '%'))) {
 693                 bufncat(h, pp, (size_t)(p - pp));
 694                 switch (*(p + 1)) {
 695                 case('S'):
 696                         bufcat(h, sec ? sec : "1");
 697                         break;
 698                 case('N'):
 699                         buffmt(h, name);
 700                         break;
 701                 default:
 702                         bufncat(h, p, 2);
 703                         break;
 704                 }
 705                 pp = p + 2;
 706         }
 707         if (pp)
 708                 bufcat(h, pp);
 709 }
 710
 711
 712 void
 713 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 714 {
 715         double           v;
 716         const char      *u;
 717
 718         v = su->scale;
 719
 720         switch (su->unit) {
 721         case (SCALE_CM):
 722                 u = "cm";
 723                 break;
 724         case (SCALE_IN):
 725                 u = "in";
 726                 break;
 727         case (SCALE_PC):
 728                 u = "pc";
 729                 break;
 730         case (SCALE_PT):
 731                 u = "pt";
 732                 break;
 733         case (SCALE_EM):
 734                 u = "em";
 735                 break;
 736         case (SCALE_MM):
 737                 if (0 == (v /= 100))
 738                         v = 1;
 739                 u = "em";
 740                 break;
 741         case (SCALE_EN):
 742                 u = "ex";
 743                 break;
 744         case (SCALE_BU):
 745                 u = "ex";
 746                 break;
 747         case (SCALE_VS):
 748                 u = "em";
 749                 break;
 750         default:
 751                 u = "ex";
 752                 break;
 753         }
 754
 755         /*
 756          * XXX: the CSS spec isn't clear as to which types accept
 757          * integer or real numbers, so we just make them all decimals.
 758          */
 759         buffmt(h, "%s: %.2f%s;", p, v, u);
 760 }
 761
 762
 763 void
 764 html_idcat(char *dst, const char *src, int sz)
 765 {
 766         int              ssz;
 767
 768         assert(sz);
 769
 770         /* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */
 771
 772         for ( ; *dst != '\0' && sz; dst++, sz--)
 773                 /* Jump to end. */ ;
 774
 775         assert(sz > 2);
 776
 777         /* We can't start with a number (bah). */
 778
 779         *dst++ = 'x';
 780         *dst = '\0';
 781         sz--;
 782
 783         for ( ; *src != '\0' && sz > 1; src++) {
 784                 ssz = snprintf(dst, (size_t)sz, "%.2x", *src);
 785                 sz -= ssz;
 786                 dst += ssz;
 787         }
 788 }