usr/src/cmd/mandoc/html.c - illumos-gate - Gitiles

 /*	$Id: html.c,v 1.150 2011/10/05 21:35:17 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <sys/types.h>

 #include <assert.h>
 #include <ctype.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "mandoc.h"
 #include "libmandoc.h"
 #include "out.h"
 #include "html.h"
 #include "main.h"

 struct	htmldata {
 	const char	 *name;
 	int		  flags;
 #define	HTML_CLRLINE	 (1 << 0)
 #define	HTML_NOSTACK	 (1 << 1)
 #define	HTML_AUTOCLOSE	 (1 << 2) /* Tag has auto-closure. */
 };

 static	const struct htmldata htmltags[TAG_MAX] = {
 	{"html",	HTML_CLRLINE}, /* TAG_HTML */
 	{"head",	HTML_CLRLINE}, /* TAG_HEAD */
 	{"body",	HTML_CLRLINE}, /* TAG_BODY */
 	{"meta",	HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_META */
 	{"title",	HTML_CLRLINE}, /* TAG_TITLE */
 	{"div",		HTML_CLRLINE}, /* TAG_DIV */
 	{"h1",		0}, /* TAG_H1 */
 	{"h2",		0}, /* TAG_H2 */
 	{"span",	0}, /* TAG_SPAN */
 	{"link",	HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_LINK */
 	{"br",		HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_BR */
 	{"a",		0}, /* TAG_A */
 	{"table",	HTML_CLRLINE}, /* TAG_TABLE */
 	{"tbody",	HTML_CLRLINE}, /* TAG_TBODY */
 	{"col",		HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_COL */
 	{"tr",		HTML_CLRLINE}, /* TAG_TR */
 	{"td",		HTML_CLRLINE}, /* TAG_TD */
 	{"li",		HTML_CLRLINE}, /* TAG_LI */
 	{"ul",		HTML_CLRLINE}, /* TAG_UL */
 	{"ol",		HTML_CLRLINE}, /* TAG_OL */
 	{"dl",		HTML_CLRLINE}, /* TAG_DL */
 	{"dt",		HTML_CLRLINE}, /* TAG_DT */
 	{"dd",		HTML_CLRLINE}, /* TAG_DD */
 	{"blockquote",	HTML_CLRLINE}, /* TAG_BLOCKQUOTE */
 	{"p",		HTML_CLRLINE | HTML_NOSTACK | HTML_AUTOCLOSE}, /* TAG_P */
 	{"pre",		HTML_CLRLINE }, /* TAG_PRE */
 	{"b",		0 }, /* TAG_B */
 	{"i",		0 }, /* TAG_I */
 	{"code",	0 }, /* TAG_CODE */
 	{"small",	0 }, /* TAG_SMALL */
 };

 static	const char	*const htmlattrs[ATTR_MAX] = {
 	"http-equiv", /* ATTR_HTTPEQUIV */
 	"content", /* ATTR_CONTENT */
 	"name", /* ATTR_NAME */
 	"rel", /* ATTR_REL */
 	"href", /* ATTR_HREF */
 	"type", /* ATTR_TYPE */
 	"media", /* ATTR_MEDIA */
 	"class", /* ATTR_CLASS */
 	"style", /* ATTR_STYLE */
 	"width", /* ATTR_WIDTH */
 	"id", /* ATTR_ID */
 	"summary", /* ATTR_SUMMARY */
 	"align", /* ATTR_ALIGN */
 	"colspan", /* ATTR_COLSPAN */
 };

 static	const char	*const roffscales[SCALE_MAX] = {
 	"cm", /* SCALE_CM */
 	"in", /* SCALE_IN */
 	"pc", /* SCALE_PC */
 	"pt", /* SCALE_PT */
 	"em", /* SCALE_EM */
 	"em", /* SCALE_MM */
 	"ex", /* SCALE_EN */
 	"ex", /* SCALE_BU */
 	"em", /* SCALE_VS */
 	"ex", /* SCALE_FS */
 };

 static	void	 bufncat(struct html *, const char *, size_t);
 static	void	 print_ctag(struct html *, enum htmltag);
 static	int	 print_encode(struct html *, const char *, int);
 static	void	 print_metaf(struct html *, enum mandoc_esc);
 static	void	 print_attr(struct html *, const char *, const char *);
 static	void	 *ml_alloc(char *, enum htmltype);

 static void *
 ml_alloc(char *outopts, enum htmltype type)
 {
 	struct html	*h;
 	const char	*toks[5];
 	char		*v;

 	toks[0] = "style";
 	toks[1] = "man";
 	toks[2] = "includes";
 	toks[3] = "fragment";
 	toks[4] = NULL;

 	h = mandoc_calloc(1, sizeof(struct html));

 	h->type = type;
 	h->tags.head = NULL;
 	h->symtab = mchars_alloc();

 	while (outopts && *outopts)
 		switch (getsubopt(&outopts, UNCONST(toks), &v)) {
 		case (0):
 			h->style = v;
 			break;
 		case (1):
 			h->base_man = v;
 			break;
 		case (2):
 			h->base_includes = v;
 			break;
 		case (3):
 			h->oflags |= HTML_FRAGMENT;
 			break;
 		default:
 			break;
 		}

 	return(h);
 }

 void *
 html_alloc(char *outopts)
 {

 	return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
 }


 void *
 xhtml_alloc(char *outopts)
 {

 	return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
 }


 void
 html_free(void *p)
 {
 	struct tag	*tag;
 	struct html	*h;

 	h = (struct html *)p;

 	while ((tag = h->tags.head) != NULL) {
 		h->tags.head = tag->next;
 		free(tag);
 	}

 	if (h->symtab)
 		mchars_free(h->symtab);

 	free(h);
 }


 void
 print_gen_head(struct html *h)
 {
 	struct htmlpair	 tag[4];

 	tag[0].key = ATTR_HTTPEQUIV;
 	tag[0].val = "Content-Type";
 	tag[1].key = ATTR_CONTENT;
 	tag[1].val = "text/html; charset=utf-8";
 	print_otag(h, TAG_META, 2, tag);

 	tag[0].key = ATTR_NAME;
 	tag[0].val = "resource-type";
 	tag[1].key = ATTR_CONTENT;
 	tag[1].val = "document";
 	print_otag(h, TAG_META, 2, tag);

 	if (h->style) {
 		tag[0].key = ATTR_REL;
 		tag[0].val = "stylesheet";
 		tag[1].key = ATTR_HREF;
 		tag[1].val = h->style;
 		tag[2].key = ATTR_TYPE;
 		tag[2].val = "text/css";
 		tag[3].key = ATTR_MEDIA;
 		tag[3].val = "all";
 		print_otag(h, TAG_LINK, 4, tag);
 	}
 }

 static void
 print_metaf(struct html *h, enum mandoc_esc deco)
 {
 	enum htmlfont	 font;

 	switch (deco) {
 	case (ESCAPE_FONTPREV):
 		font = h->metal;
 		break;
 	case (ESCAPE_FONTITALIC):
 		font = HTMLFONT_ITALIC;
 		break;
 	case (ESCAPE_FONTBOLD):
 		font = HTMLFONT_BOLD;
 		break;
 	case (ESCAPE_FONT):
 		/* FALLTHROUGH */
 	case (ESCAPE_FONTROMAN):
 		font = HTMLFONT_NONE;
 		break;
 	default:
 		abort();
 		/* NOTREACHED */
 	}

 	if (h->metaf) {
 		print_tagq(h, h->metaf);
 		h->metaf = NULL;
 	}

 	h->metal = h->metac;
 	h->metac = font;

 	if (HTMLFONT_NONE != font)
 		h->metaf = HTMLFONT_BOLD == font ?
 			print_otag(h, TAG_B, 0, NULL) :
 			print_otag(h, TAG_I, 0, NULL);
 }

 int
 html_strlen(const char *cp)
 {
 	int		 ssz, sz;
 	const char	*seq, *p;

 	/*
 	 * Account for escaped sequences within string length
 	 * calculations.  This follows the logic in term_strlen() as we
 	 * must calculate the width of produced strings.
 	 * Assume that characters are always width of "1".  This is
 	 * hacky, but it gets the job done for approximation of widths.
 	 */

 	sz = 0;
 	while (NULL != (p = strchr(cp, '\\'))) {
 		sz += (int)(p - cp);
 		++cp;
 		switch (mandoc_escape(&cp, &seq, &ssz)) {
 		case (ESCAPE_ERROR):
 			return(sz);
 		case (ESCAPE_UNICODE):
 			/* FALLTHROUGH */
 		case (ESCAPE_NUMBERED):
 			/* FALLTHROUGH */
 		case (ESCAPE_SPECIAL):
 			sz++;
 			break;
 		default:
 			break;
 		}
 	}

 	assert(sz >= 0);
 	return(sz + strlen(cp));
 }

 static int
 print_encode(struct html *h, const char *p, int norecurse)
 {
 	size_t		 sz;
 	int		 c, len, nospace;
 	const char	*seq;
 	enum mandoc_esc	 esc;
 	static const char rejs[6] = { '\\', '<', '>', '&', ASCII_HYPH, '\0' };

 	nospace = 0;

 	while ('\0' != *p) {
 		sz = strcspn(p, rejs);

 		fwrite(p, 1, sz, stdout);
 		p += (int)sz;

 		if ('\0' == *p)
 			break;

 		switch (*p++) {
 		case ('<'):
 			printf("&lt;");
 			continue;
 		case ('>'):
 			printf("&gt;");
 			continue;
 		case ('&'):
 			printf("&amp;");
 			continue;
 		case (ASCII_HYPH):
 			putchar('-');
 			continue;
 		default:
 			break;
 		}

 		esc = mandoc_escape(&p, &seq, &len);
 		if (ESCAPE_ERROR == esc)
 			break;

 		switch (esc) {
 		case (ESCAPE_UNICODE):
 			/* Skip passed "u" header. */
 			c = mchars_num2uc(seq + 1, len - 1);
 			if ('\0' != c)
 				printf("&#x%x;", c);
 			break;
 		case (ESCAPE_NUMBERED):
 			c = mchars_num2char(seq, len);
 			if ('\0' != c)
 				putchar(c);
 			break;
 		case (ESCAPE_SPECIAL):
 			c = mchars_spec2cp(h->symtab, seq, len);
 			if (c > 0)
 				printf("&#%d;", c);
 			else if (-1 == c && 1 == len)
 				putchar((int)*seq);
 			break;
 		case (ESCAPE_FONT):
 			/* FALLTHROUGH */
 		case (ESCAPE_FONTPREV):
 			/* FALLTHROUGH */
 		case (ESCAPE_FONTBOLD):
 			/* FALLTHROUGH */
 		case (ESCAPE_FONTITALIC):
 			/* FALLTHROUGH */
 		case (ESCAPE_FONTROMAN):
 			if (norecurse)
 				break;
 			print_metaf(h, esc);
 			break;
 		case (ESCAPE_NOSPACE):
 			if ('\0' == *p)
 				nospace = 1;
 			break;
 		default:
 			break;
 		}
 	}

 	return(nospace);
 }


 static void
 print_attr(struct html *h, const char *key, const char *val)
 {
 	printf(" %s=\"", key);
 	(void)print_encode(h, val, 1);
 	putchar('\"');
 }


 struct tag *
 print_otag(struct html *h, enum htmltag tag,
 		int sz, const struct htmlpair *p)
 {
 	int		 i;
 	struct tag	*t;

 	/* Push this tags onto the stack of open scopes. */

 	if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
 		t = mandoc_malloc(sizeof(struct tag));
 		t->tag = tag;
 		t->next = h->tags.head;
 		h->tags.head = t;
 	} else
 		t = NULL;

 	if ( ! (HTML_NOSPACE & h->flags))
 		if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
 			/* Manage keeps! */
 			if ( ! (HTML_KEEP & h->flags)) {
 				if (HTML_PREKEEP & h->flags)
 					h->flags |= HTML_KEEP;
 				putchar(' ');
 			} else
 				printf("&#160;");
 		}

 	if ( ! (h->flags & HTML_NONOSPACE))
 		h->flags &= ~HTML_NOSPACE;
 	else
 		h->flags |= HTML_NOSPACE;

 	/* Print out the tag name and attributes. */

 	printf("<%s", htmltags[tag].name);
 	for (i = 0; i < sz; i++)
 		print_attr(h, htmlattrs[p[i].key], p[i].val);

 	/* Add non-overridable attributes. */

 	if (TAG_HTML == tag && HTML_XHTML_1_0_STRICT == h->type) {
 		print_attr(h, "xmlns", "http://www.w3.org/1999/xhtml");
 		print_attr(h, "xml:lang", "en");
 		print_attr(h, "lang", "en");
 	}

 	/* Accommodate for XML "well-formed" singleton escaping. */

 	if (HTML_AUTOCLOSE & htmltags[tag].flags)
 		switch (h->type) {
 		case (HTML_XHTML_1_0_STRICT):
 			putchar('/');
 			break;
 		default:
 			break;
 		}

 	putchar('>');

 	h->flags |= HTML_NOSPACE;

 	if ((HTML_AUTOCLOSE | HTML_CLRLINE) & htmltags[tag].flags)
 		putchar('\n');

 	return(t);
 }


 static void
 print_ctag(struct html *h, enum htmltag tag)
 {

 	printf("</%s>", htmltags[tag].name);
 	if (HTML_CLRLINE & htmltags[tag].flags) {
 		h->flags |= HTML_NOSPACE;
 		putchar('\n');
 	}
 }

 void
 print_gen_decls(struct html *h)
 {
 	const char	*doctype;
 	const char	*dtd;
 	const char	*name;

 	switch (h->type) {
 	case (HTML_HTML_4_01_STRICT):
 		name = "HTML";
 		doctype = "-//W3C//DTD HTML 4.01//EN";
 		dtd = "http://www.w3.org/TR/html4/strict.dtd";
 		break;
 	default:
 		puts("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
 		name = "html";
 		doctype = "-//W3C//DTD XHTML 1.0 Strict//EN";
 		dtd = "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";
 		break;
 	}

 	printf("<!DOCTYPE %s PUBLIC \"%s\" \"%s\">\n",
 			name, doctype, dtd);
 }

 void
 print_text(struct html *h, const char *word)
 {

 	if ( ! (HTML_NOSPACE & h->flags)) {
 		/* Manage keeps! */
 		if ( ! (HTML_KEEP & h->flags)) {
 			if (HTML_PREKEEP & h->flags)
 				h->flags |= HTML_KEEP;
 			putchar(' ');
 		} else
 			printf("&#160;");
 	}

 	assert(NULL == h->metaf);
 	if (HTMLFONT_NONE != h->metac)
 		h->metaf = HTMLFONT_BOLD == h->metac ?
 			print_otag(h, TAG_B, 0, NULL) :
 			print_otag(h, TAG_I, 0, NULL);

 	assert(word);
 	if ( ! print_encode(h, word, 0)) {
 		if ( ! (h->flags & HTML_NONOSPACE))
 			h->flags &= ~HTML_NOSPACE;
 	} else
 		h->flags |= HTML_NOSPACE;

 	if (h->metaf) {
 		print_tagq(h, h->metaf);
 		h->metaf = NULL;
 	}

 	h->flags &= ~HTML_IGNDELIM;
 }


 void
 print_tagq(struct html *h, const struct tag *until)
 {
 	struct tag	*tag;

 	while ((tag = h->tags.head) != NULL) {
 		/*
 		 * Remember to close out and nullify the current
 		 * meta-font and table, if applicable.
 		 */
 		if (tag == h->metaf)
 			h->metaf = NULL;
 		if (tag == h->tblt)
 			h->tblt = NULL;
 		print_ctag(h, tag->tag);
 		h->tags.head = tag->next;
 		free(tag);
 		if (until && tag == until)
 			return;
 	}
 }


 void
 print_stagq(struct html *h, const struct tag *suntil)
 {
 	struct tag	*tag;

 	while ((tag = h->tags.head) != NULL) {
 		if (suntil && tag == suntil)
 			return;
 		/*
 		 * Remember to close out and nullify the current
 		 * meta-font and table, if applicable.
 		 */
 		if (tag == h->metaf)
 			h->metaf = NULL;
 		if (tag == h->tblt)
 			h->tblt = NULL;
 		print_ctag(h, tag->tag);
 		h->tags.head = tag->next;
 		free(tag);
 	}
 }

 void
 bufinit(struct html *h)
 {

 	h->buf[0] = '\0';
 	h->buflen = 0;
 }

 void
 bufcat_style(struct html *h, const char *key, const char *val)
 {

 	bufcat(h, key);
 	bufcat(h, ":");
 	bufcat(h, val);
 	bufcat(h, ";");
 }

 void
 bufcat(struct html *h, const char *p)
 {

 	h->buflen = strlcat(h->buf, p, BUFSIZ);
 	assert(h->buflen < BUFSIZ);
 }

 void
 bufcat_fmt(struct html *h, const char *fmt, ...)
 {
 	va_list		 ap;

 	va_start(ap, fmt);
 	(void)vsnprintf(h->buf + (int)h->buflen,
 			BUFSIZ - h->buflen - 1, fmt, ap);
 	va_end(ap);
 	h->buflen = strlen(h->buf);
 }

 static void
 bufncat(struct html *h, const char *p, size_t sz)
 {

 	assert(h->buflen + sz + 1 < BUFSIZ);
 	strncat(h->buf, p, sz);
 	h->buflen += sz;
 }

 void
 buffmt_includes(struct html *h, const char *name)
 {
 	const char	*p, *pp;

 	pp = h->base_includes;

 	bufinit(h);
 	while (NULL != (p = strchr(pp, '%'))) {
 		bufncat(h, pp, (size_t)(p - pp));
 		switch (*(p + 1)) {
 		case('I'):
 			bufcat(h, name);
 			break;
 		default:
 			bufncat(h, p, 2);
 			break;
 		}
 		pp = p + 2;
 	}
 	if (pp)
 		bufcat(h, pp);
 }

 void
 buffmt_man(struct html *h,
 		const char *name, const char *sec)
 {
 	const char	*p, *pp;

 	pp = h->base_man;

 	bufinit(h);
 	while (NULL != (p = strchr(pp, '%'))) {
 		bufncat(h, pp, (size_t)(p - pp));
 		switch (*(p + 1)) {
 		case('S'):
 			bufcat(h, sec ? sec : "1");
 			break;
 		case('N'):
 			bufcat_fmt(h, name);
 			break;
 		default:
 			bufncat(h, p, 2);
 			break;
 		}
 		pp = p + 2;
 	}
 	if (pp)
 		bufcat(h, pp);
 }

 void
 bufcat_su(struct html *h, const char *p, const struct roffsu *su)
 {
 	double		 v;

 	v = su->scale;
 	if (SCALE_MM == su->unit && 0.0 == (v /= 100.0))
 		v = 1.0;

 	bufcat_fmt(h, "%s: %.2f%s;", p, v, roffscales[su->unit]);
 }

 void
 bufcat_id(struct html *h, const char *src)
 {

 	/* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */

 	while ('\0' != *src)
 		bufcat_fmt(h, "%.2x", *src++);
 }
	/* $Id: html.c,v 1.150 2011/10/05 21:35:17 kristaps Exp $ */
	/*
	* Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
	* Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/
	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#include <sys/types.h>

	#include <assert.h>
	#include <ctype.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "mandoc.h"
	#include "libmandoc.h"
	#include "out.h"
	#include "html.h"
	#include "main.h"

	struct htmldata {
	const char *name;
	int flags;
	#define HTML_CLRLINE (1 << 0)
	#define HTML_NOSTACK (1 << 1)
	#define HTML_AUTOCLOSE (1 << 2) /* Tag has auto-closure. */
	};

	static const struct htmldata htmltags[TAG_MAX] = {
	{"html", HTML_CLRLINE}, /* TAG_HTML */
	{"head", HTML_CLRLINE}, /* TAG_HEAD */
	{"body", HTML_CLRLINE}, /* TAG_BODY */
	{"meta", HTML_CLRLINE \| HTML_NOSTACK \| HTML_AUTOCLOSE}, /* TAG_META */
	{"title", HTML_CLRLINE}, /* TAG_TITLE */
	{"div", HTML_CLRLINE}, /* TAG_DIV */
	{"h1", 0}, /* TAG_H1 */
	{"h2", 0}, /* TAG_H2 */
	{"span", 0}, /* TAG_SPAN */
	{"link", HTML_CLRLINE \| HTML_NOSTACK \| HTML_AUTOCLOSE}, /* TAG_LINK */
	{"br", HTML_CLRLINE \| HTML_NOSTACK \| HTML_AUTOCLOSE}, /* TAG_BR */
	{"a", 0}, /* TAG_A */
	{"table", HTML_CLRLINE}, /* TAG_TABLE */
	{"tbody", HTML_CLRLINE}, /* TAG_TBODY */
	{"col", HTML_CLRLINE \| HTML_NOSTACK \| HTML_AUTOCLOSE}, /* TAG_COL */
	{"tr", HTML_CLRLINE}, /* TAG_TR */
	{"td", HTML_CLRLINE}, /* TAG_TD */
	{"li", HTML_CLRLINE}, /* TAG_LI */
	{"ul", HTML_CLRLINE}, /* TAG_UL */
	{"ol", HTML_CLRLINE}, /* TAG_OL */
	{"dl", HTML_CLRLINE}, /* TAG_DL */
	{"dt", HTML_CLRLINE}, /* TAG_DT */
	{"dd", HTML_CLRLINE}, /* TAG_DD */
	{"blockquote", HTML_CLRLINE}, /* TAG_BLOCKQUOTE */
	{"p", HTML_CLRLINE \| HTML_NOSTACK \| HTML_AUTOCLOSE}, /* TAG_P */
	{"pre", HTML_CLRLINE }, /* TAG_PRE */
	{"b", 0 }, /* TAG_B */
	{"i", 0 }, /* TAG_I */
	{"code", 0 }, /* TAG_CODE */
	{"small", 0 }, /* TAG_SMALL */
	};

	static const char *const htmlattrs[ATTR_MAX] = {
	"http-equiv", /* ATTR_HTTPEQUIV */
	"content", /* ATTR_CONTENT */
	"name", /* ATTR_NAME */
	"rel", /* ATTR_REL */
	"href", /* ATTR_HREF */
	"type", /* ATTR_TYPE */
	"media", /* ATTR_MEDIA */
	"class", /* ATTR_CLASS */
	"style", /* ATTR_STYLE */
	"width", /* ATTR_WIDTH */
	"id", /* ATTR_ID */
	"summary", /* ATTR_SUMMARY */
	"align", /* ATTR_ALIGN */
	"colspan", /* ATTR_COLSPAN */
	};

	static const char *const roffscales[SCALE_MAX] = {
	"cm", /* SCALE_CM */
	"in", /* SCALE_IN */
	"pc", /* SCALE_PC */
	"pt", /* SCALE_PT */
	"em", /* SCALE_EM */
	"em", /* SCALE_MM */
	"ex", /* SCALE_EN */
	"ex", /* SCALE_BU */
	"em", /* SCALE_VS */
	"ex", /* SCALE_FS */
	};

	static void bufncat(struct html , const char , size_t);
	static void print_ctag(struct html *, enum htmltag);
	static int print_encode(struct html , const char , int);
	static void print_metaf(struct html *, enum mandoc_esc);
	static void print_attr(struct html , const char , const char *);
	static void ml_alloc(char , enum htmltype);

	static void *
	ml_alloc(char *outopts, enum htmltype type)
	{
	struct html *h;
	const char *toks[5];
	char *v;

	toks[0] = "style";
	toks[1] = "man";
	toks[2] = "includes";
	toks[3] = "fragment";
	toks[4] = NULL;

	h = mandoc_calloc(1, sizeof(struct html));

	h->type = type;
	h->tags.head = NULL;
	h->symtab = mchars_alloc();

	while (outopts && *outopts)
	switch (getsubopt(&outopts, UNCONST(toks), &v)) {
	case (0):
	h->style = v;
	break;
	case (1):
	h->base_man = v;
	break;
	case (2):
	h->base_includes = v;
	break;
	case (3):
	h->oflags \|= HTML_FRAGMENT;
	break;
	default:
	break;
	}

	return(h);
	}

	void *
	html_alloc(char *outopts)
	{

	return(ml_alloc(outopts, HTML_HTML_4_01_STRICT));
	}


	void *
	xhtml_alloc(char *outopts)
	{

	return(ml_alloc(outopts, HTML_XHTML_1_0_STRICT));
	}


	void
	html_free(void *p)
	{
	struct tag *tag;
	struct html *h;

	h = (struct html *)p;

	while ((tag = h->tags.head) != NULL) {
	h->tags.head = tag->next;
	free(tag);
	}

	if (h->symtab)
	mchars_free(h->symtab);

	free(h);
	}


	void
	print_gen_head(struct html *h)
	{
	struct htmlpair tag[4];

	tag[0].key = ATTR_HTTPEQUIV;
	tag[0].val = "Content-Type";
	tag[1].key = ATTR_CONTENT;
	tag[1].val = "text/html; charset=utf-8";
	print_otag(h, TAG_META, 2, tag);

	tag[0].key = ATTR_NAME;
	tag[0].val = "resource-type";
	tag[1].key = ATTR_CONTENT;
	tag[1].val = "document";
	print_otag(h, TAG_META, 2, tag);

	if (h->style) {
	tag[0].key = ATTR_REL;
	tag[0].val = "stylesheet";
	tag[1].key = ATTR_HREF;
	tag[1].val = h->style;
	tag[2].key = ATTR_TYPE;
	tag[2].val = "text/css";
	tag[3].key = ATTR_MEDIA;
	tag[3].val = "all";
	print_otag(h, TAG_LINK, 4, tag);
	}
	}

	static void
	print_metaf(struct html *h, enum mandoc_esc deco)
	{
	enum htmlfont font;

	switch (deco) {
	case (ESCAPE_FONTPREV):
	font = h->metal;
	break;
	case (ESCAPE_FONTITALIC):
	font = HTMLFONT_ITALIC;
	break;
	case (ESCAPE_FONTBOLD):
	font = HTMLFONT_BOLD;
	break;
	case (ESCAPE_FONT):
	/* FALLTHROUGH */
	case (ESCAPE_FONTROMAN):
	font = HTMLFONT_NONE;
	break;
	default:
	abort();
	/* NOTREACHED */
	}

	if (h->metaf) {
	print_tagq(h, h->metaf);
	h->metaf = NULL;
	}

	h->metal = h->metac;
	h->metac = font;

	if (HTMLFONT_NONE != font)
	h->metaf = HTMLFONT_BOLD == font ?
	print_otag(h, TAG_B, 0, NULL) :
	print_otag(h, TAG_I, 0, NULL);
	}

	int
	html_strlen(const char *cp)
	{
	int ssz, sz;
	const char seq, p;

	/*
	* Account for escaped sequences within string length
	* calculations. This follows the logic in term_strlen() as we
	* must calculate the width of produced strings.
	* Assume that characters are always width of "1". This is
	* hacky, but it gets the job done for approximation of widths.
	*/

	sz = 0;
	while (NULL != (p = strchr(cp, '\\'))) {
	sz += (int)(p - cp);
	++cp;
	switch (mandoc_escape(&cp, &seq, &ssz)) {
	case (ESCAPE_ERROR):
	return(sz);
	case (ESCAPE_UNICODE):
	/* FALLTHROUGH */
	case (ESCAPE_NUMBERED):
	/* FALLTHROUGH */
	case (ESCAPE_SPECIAL):
	sz++;
	break;
	default:
	break;
	}
	}

	assert(sz >= 0);
	return(sz + strlen(cp));
	}

	static int
	print_encode(struct html h, const char p, int norecurse)
	{
	size_t sz;
	int c, len, nospace;
	const char *seq;
	enum mandoc_esc esc;
	static const char rejs[6] = { '\\', '<', '>', '&', ASCII_HYPH, '\0' };

	nospace = 0;

	while ('\0' != *p) {
	sz = strcspn(p, rejs);

	fwrite(p, 1, sz, stdout);
	p += (int)sz;

	if ('\0' == *p)
	break;

	switch (*p++) {
	case ('<'):
	printf("<");
	continue;
	case ('>'):
	printf(">");
	continue;
	case ('&'):
	printf("&");
	continue;
	case (ASCII_HYPH):
	putchar('-');
	continue;
	default:
	break;
	}

	esc = mandoc_escape(&p, &seq, &len);
	if (ESCAPE_ERROR == esc)
	break;

	switch (esc) {
	case (ESCAPE_UNICODE):
	/* Skip passed "u" header. */
	c = mchars_num2uc(seq + 1, len - 1);
	if ('\0' != c)
	printf("&#x%x;", c);
	break;
	case (ESCAPE_NUMBERED):
	c = mchars_num2char(seq, len);
	if ('\0' != c)
	putchar(c);
	break;
	case (ESCAPE_SPECIAL):
	c = mchars_spec2cp(h->symtab, seq, len);
	if (c > 0)
	printf("&#%d;", c);
	else if (-1 == c && 1 == len)
	putchar((int)*seq);
	break;
	case (ESCAPE_FONT):
	/* FALLTHROUGH */
	case (ESCAPE_FONTPREV):
	/* FALLTHROUGH */
	case (ESCAPE_FONTBOLD):
	/* FALLTHROUGH */
	case (ESCAPE_FONTITALIC):
	/* FALLTHROUGH */
	case (ESCAPE_FONTROMAN):
	if (norecurse)
	break;
	print_metaf(h, esc);
	break;
	case (ESCAPE_NOSPACE):
	if ('\0' == *p)
	nospace = 1;
	break;
	default:
	break;
	}
	}

	return(nospace);
	}


	static void
	print_attr(struct html h, const char key, const char *val)
	{
	printf(" %s=\"", key);
	(void)print_encode(h, val, 1);
	putchar('\"');
	}


	struct tag *
	print_otag(struct html *h, enum htmltag tag,
	int sz, const struct htmlpair *p)
	{
	int i;
	struct tag *t;

	/* Push this tags onto the stack of open scopes. */

	if ( ! (HTML_NOSTACK & htmltags[tag].flags)) {
	t = mandoc_malloc(sizeof(struct tag));
	t->tag = tag;
	t->next = h->tags.head;
	h->tags.head = t;
	} else
	t = NULL;

	if ( ! (HTML_NOSPACE & h->flags))
	if ( ! (HTML_CLRLINE & htmltags[tag].flags)) {
	/* Manage keeps! */
	if ( ! (HTML_KEEP & h->flags)) {
	if (HTML_PREKEEP & h->flags)
	h->flags \|= HTML_KEEP;
	putchar(' ');
	} else
	printf(" ");
	}

	if ( ! (h->flags & HTML_NONOSPACE))
	h->flags &= ~HTML_NOSPACE;
	else
	h->flags \|= HTML_NOSPACE;

	/* Print out the tag name and attributes. */

	printf("<%s", htmltags[tag].name);
	for (i = 0; i < sz; i++)
	print_attr(h, htmlattrs[p[i].key], p[i].val);

	/* Add non-overridable attributes. */

	if (TAG_HTML == tag && HTML_XHTML_1_0_STRICT == h->type) {
	print_attr(h, "xmlns", "http://www.w3.org/1999/xhtml");
	print_attr(h, "xml:lang", "en");
	print_attr(h, "lang", "en");
	}

	/* Accommodate for XML "well-formed" singleton escaping. */

	if (HTML_AUTOCLOSE & htmltags[tag].flags)
	switch (h->type) {
	case (HTML_XHTML_1_0_STRICT):
	putchar('/');
	break;
	default:
	break;
	}

	putchar('>');

	h->flags \|= HTML_NOSPACE;

	if ((HTML_AUTOCLOSE \| HTML_CLRLINE) & htmltags[tag].flags)
	putchar('\n');

	return(t);
	}


	static void
	print_ctag(struct html *h, enum htmltag tag)
	{

	printf("</%s>", htmltags[tag].name);
	if (HTML_CLRLINE & htmltags[tag].flags) {
	h->flags \|= HTML_NOSPACE;
	putchar('\n');
	}
	}

	void
	print_gen_decls(struct html *h)
	{
	const char *doctype;
	const char *dtd;
	const char *name;

	switch (h->type) {
	case (HTML_HTML_4_01_STRICT):
	name = "HTML";
	doctype = "-//W3C//DTD HTML 4.01//EN";
	dtd = "http://www.w3.org/TR/html4/strict.dtd";
	break;
	default:
	puts("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
	name = "html";
	doctype = "-//W3C//DTD XHTML 1.0 Strict//EN";
	dtd = "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd";
	break;
	}

	printf("<!DOCTYPE %s PUBLIC \"%s\" \"%s\">\n",
	name, doctype, dtd);
	}

	void
	print_text(struct html h, const char word)
	{

	if ( ! (HTML_NOSPACE & h->flags)) {
	/* Manage keeps! */
	if ( ! (HTML_KEEP & h->flags)) {
	if (HTML_PREKEEP & h->flags)
	h->flags \|= HTML_KEEP;
	putchar(' ');
	} else
	printf(" ");
	}

	assert(NULL == h->metaf);
	if (HTMLFONT_NONE != h->metac)
	h->metaf = HTMLFONT_BOLD == h->metac ?
	print_otag(h, TAG_B, 0, NULL) :
	print_otag(h, TAG_I, 0, NULL);

	assert(word);
	if ( ! print_encode(h, word, 0)) {
	if ( ! (h->flags & HTML_NONOSPACE))
	h->flags &= ~HTML_NOSPACE;
	} else
	h->flags \|= HTML_NOSPACE;

	if (h->metaf) {
	print_tagq(h, h->metaf);
	h->metaf = NULL;
	}

	h->flags &= ~HTML_IGNDELIM;
	}


	void
	print_tagq(struct html h, const struct tag until)
	{
	struct tag *tag;

	while ((tag = h->tags.head) != NULL) {
	/*
	* Remember to close out and nullify the current
	* meta-font and table, if applicable.
	*/
	if (tag == h->metaf)
	h->metaf = NULL;
	if (tag == h->tblt)
	h->tblt = NULL;
	print_ctag(h, tag->tag);
	h->tags.head = tag->next;
	free(tag);
	if (until && tag == until)
	return;
	}
	}


	void
	print_stagq(struct html h, const struct tag suntil)
	{
	struct tag *tag;

	while ((tag = h->tags.head) != NULL) {
	if (suntil && tag == suntil)
	return;
	/*
	* Remember to close out and nullify the current
	* meta-font and table, if applicable.
	*/
	if (tag == h->metaf)
	h->metaf = NULL;
	if (tag == h->tblt)
	h->tblt = NULL;
	print_ctag(h, tag->tag);
	h->tags.head = tag->next;
	free(tag);
	}
	}

	void
	bufinit(struct html *h)
	{

	h->buf[0] = '\0';
	h->buflen = 0;
	}

	void
	bufcat_style(struct html h, const char key, const char *val)
	{

	bufcat(h, key);
	bufcat(h, ":");
	bufcat(h, val);
	bufcat(h, ";");
	}

	void
	bufcat(struct html h, const char p)
	{

	h->buflen = strlcat(h->buf, p, BUFSIZ);
	assert(h->buflen < BUFSIZ);
	}

	void
	bufcat_fmt(struct html h, const char fmt, ...)
	{
	va_list ap;

	va_start(ap, fmt);
	(void)vsnprintf(h->buf + (int)h->buflen,
	BUFSIZ - h->buflen - 1, fmt, ap);
	va_end(ap);
	h->buflen = strlen(h->buf);
	}

	static void
	bufncat(struct html h, const char p, size_t sz)
	{

	assert(h->buflen + sz + 1 < BUFSIZ);
	strncat(h->buf, p, sz);
	h->buflen += sz;
	}

	void
	buffmt_includes(struct html h, const char name)
	{
	const char p, pp;

	pp = h->base_includes;

	bufinit(h);
	while (NULL != (p = strchr(pp, '%'))) {
	bufncat(h, pp, (size_t)(p - pp));
	switch (*(p + 1)) {
	case('I'):
	bufcat(h, name);
	break;
	default:
	bufncat(h, p, 2);
	break;
	}
	pp = p + 2;
	}
	if (pp)
	bufcat(h, pp);
	}

	void
	buffmt_man(struct html *h,
	const char name, const char sec)
	{
	const char p, pp;

	pp = h->base_man;

	bufinit(h);
	while (NULL != (p = strchr(pp, '%'))) {
	bufncat(h, pp, (size_t)(p - pp));
	switch (*(p + 1)) {
	case('S'):
	bufcat(h, sec ? sec : "1");
	break;
	case('N'):
	bufcat_fmt(h, name);
	break;
	default:
	bufncat(h, p, 2);
	break;
	}
	pp = p + 2;
	}
	if (pp)
	bufcat(h, pp);
	}

	void
	bufcat_su(struct html h, const char p, const struct roffsu *su)
	{
	double v;

	v = su->scale;
	if (SCALE_MM == su->unit && 0.0 == (v /= 100.0))
	v = 1.0;

	bufcat_fmt(h, "%s: %.2f%s;", p, v, roffscales[su->unit]);
	}

	void
	bufcat_id(struct html h, const char src)
	{

	/* Cf. <http://www.w3.org/TR/html4/types.html#h-6.2>. */

	while ('\0' != *src)
	bufcat_fmt(h, "%.2x", *src++);
	}