/* (C) 1997 Robert de Bath
 * (C) 2013 rofl0r
 * under the terms of the GPL.
 *
 * This is a manual pager program, it will search for and format manual
 * pages which it then pipes to more.
 *
 * The program understands manual pages that have been compressed with
 * either 'compress' or 'gzip' and will decompress them on the fly.
 *
 * The environment is checked for these variables:
 *   MANSECT=1:2:3:4:5:6:7:8:9		# Manual section search order.
 *   MANPATH=/usr/local/man:/usr/man	# Directorys to search for man tree.
 *   PAGER=more				# pager progam to use.
 *   PATH=...				# Search for gzip/uncompress
 *
 * The program will display documents that are either in it's own "nroff -man"
 * like format or in "catman" format, it will not correctly display pages in
 * the BSD '-mdoc' format.
 *
 * Neither nroff nor any similar program is needed as this program has it's
 * own built in _man_ _page_ _formatter_. This is NOT an nroff clone and will
 * not (for instance) understand macros or tbl constructs.
 *
 * Unlike groff this is small, fast and picky!
 */

#define DONT_SPLATTER		/* Lots of messages out */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include <string.h>
#include <assert.h>
#include <sys/ioctl.h>

static FILE *ofd, *ifd;
static int *line_ptr;

static int keep_nl;		/* How many nl to keep til eof */
static int optional_keep;		/* Is the next keep optional ? */
static int pending_nl;		/* Is there a pending newline on output? */
static int no_fill;		/* Disable 'filling' of lines */
static int left_indent;		/* Current step of left margin */
static int old_para_indent;	/* Indent to go back to after this paragraph */
static int is_tty;
static int current_line;		/* Line number = ? */
static int gaps_on_line;		/* Gaps on line for adjustments */
static int flg_w;
static int disable_pp;

static int line[256];			/* Buffer for building output line */
static char whitespace[256];
static char line_header[256];	/* Page header line */
static char doc_footer[256];	/* Document footer line */
static char man_file[256];
static char word[80];			/* Current word */

static int right_margin = 65;		/* Don't print past this column */
static int verbose = 1;		/* print warnings about unknown macros */
static int no_nl = 1;			/* Next NL in input file is ignored */
static int catmode = 1;		/* Have we seen a '.XX' command ? */
static int cur_font = 0x100;		/* Current font, 1 == Roman */
static int next_line_indent = -1;	/* Indent after next line_break */
static int input_tab = 8;		/* Tab width in input file */
static int right_adjust = 1;		/* Adjust right margin */
static int standard_tab = 5;		/* Amount left margin stepped by */


static int lineno = 1;

static int find_page(char *name, char *sect);
static void step(char **pcurr, char **pnext);
static int open_page(char *name);
static void close_page(void);
static void do_file(void);
static int fetch_word(void);
static int do_command(void);
static void do_skipeol(void);
static int do_fontwords(int this_font, int other_font, int early_exit);
static int do_noargs(int cmd_id);
static int do_argvcmd(int cmd_id);
static void build_headers(void);
static void print_word(char *pword);
static void line_break(void);
static void page_break(void);
static void print_header(void);
static void print_doc_footer(void);

static void usage(void)
{
	fprintf(stderr, "man [-w] [-v|-q] [-P] [section-number] page\n"
	"-w\tonly print the location of matching manpages\n"
	"-v\tForce verbose output. (default)\n"
	"-q\tForce quiet output.\n"
	"-P\tDisable usage of manpp preprocessor\n"
	"`page` may be specified as `-`, in which case stdin is used.\n");
	exit(1);
}

/****************************************************************************
 * Main routine, hunt down the manpage.
 */
int main(int argc, char **argv) {
	ofd = 0;
	ifd = 0;
	int do_pclose_ofd = 0;
	int ar;
	char *mansect = 0;
	char *manname = 0;

	for(ar = 1; ar < argc; ar++)
		if(argv[ar][0] == '-' && argv[ar][1]) {
			char *p;
			for(p = argv[ar] + 1; *p; p++)
				switch (*p) {
					case 'w':
						flg_w = 1;
						break;
					case 'v':
						verbose = 1;
						break;
					case 'q':
						verbose = 0;
						break;
					case 'P':
						disable_pp = 1;
						break;
				}
		} else if(argv[ar][0] == '-') {
			manname = "<stdin>";
			ifd = stdin;
		} else if(isdigit(argv[ar][0]))
			mansect = argv[ar];
		else if(manname == 0)
			manname = argv[ar];
		else if(mansect == 0) {
			mansect = manname;
			manname = argv[ar];
		} else {
			fprintf(stderr, "Ignoring argument %s\n", argv[ar]);
			break;
		}

	if(manname == 0) usage();

	if(!ifd && find_page(manname, mansect) < 0) {
		if(mansect)
			fprintf(stderr, "No entry for %s in section %s of the manual.\n", manname, mansect);
		else
			fprintf(stderr, "No manual entry for %s\n", manname);
		exit(1);
	}
	if(flg_w)
		exit(0);

	/* ifd is now the file - display it */
	if(isatty(1)) {		/* If writing to a tty do it to a pager */
		is_tty = 1;
		char *pager = getenv("PAGER");
		if(pager) ofd = popen(pager, "w");
		if(!ofd) ofd = popen("less", "w");
		if(!ofd) ofd = popen("more", "w");
		if(!ofd) ofd = stdout;
		else {
			do_pclose_ofd = 1;
#ifdef TIOCGWINSZ
			struct winsize ws;
			if(!ioctl(0, TIOCGWINSZ, &ws))
				right_margin = ws.ws_col>251 ? 250 : ws.ws_col-2;
			else
#endif
			right_margin = 78;
		}
	} else
		ofd = stdout;

	do_file();

	/* Close files */
	if(do_pclose_ofd)
		pclose(ofd);
	close_page();
	exit(0);
}

static int find_page(char *name, char *sect) {
	static char defpath[] = "/usr/local/share/man:/usr/share/man";
	static char defsect[] = "1p:1:1perl:2:3p:3:3perl:4:5:6:7:8:9:0p";
	static char defsuff[] = ":.gz:.xz";
	static char manorcat[] = "man:cat";

	char fbuf[256];
	char *manpath;
	char *mansect = sect;
	char *mansuff;
	char *mc, *mp, *ms, *su, *nmc, *nmp, *nms, *nsu;
	int rv = -1;

	manpath = getenv("MANPATH");
	if(!manpath)
		manpath = defpath;
	if(!mansect)
		mansect = getenv("MANSECT");
	if(!mansect)
		mansect = defsect;
	mansuff = defsuff;

	if(strchr(name, '/')) {
		for(su = nsu = mansuff, step(&su, &nsu); su; step(&su, &nsu)) {
			snprintf(fbuf, sizeof(fbuf), "%s%s", name, su);
			if((rv = open_page(fbuf)) >= 0)
				break;
		}
		*man_file = 0;
		return rv;
	}

	/* SEARCH!! */
	for(mc = nmc = manorcat, step(&mc, &nmc); mc; step(&mc, &nmc))
		for(ms = nms = mansect, step(&ms, &nms); ms; step(&ms, &nms))
			for(mp = nmp = manpath, step(&mp, &nmp); mp; step(&mp, &nmp))
				for(su = nsu = mansuff, step(&su, &nsu); su; step(&su, &nsu)) {
					snprintf(fbuf, sizeof fbuf, "%s/%s%s/%s.%s%s", mp, mc, ms, name, ms, su);

					/* Got it ? */
					if(access(fbuf, 0) < 0)
						continue;
					if(flg_w) {
						printf("%s\n", fbuf);
						rv = 0;
						continue;
					}

					/* Try it ! */
					if((rv = open_page(fbuf)) >= 0) {
						char *p;
						snprintf(man_file, sizeof man_file, "%s", fbuf);
						p = strrchr(man_file, '/');
						if(p)
							*p = 0;
						p = strrchr(man_file, '/');
						if(p)
							p[1] = 0;
						return 0;
					}
				}

	return rv;
}

static void step(char **pcurr, char **pnext) {
	char *curr = *pcurr;
	char *next = *pnext;

	if(curr == 0)
		return;
	if(curr == next) {
		next = strchr(curr, ':');
		if(next)
			*next++ = 0;
	} else {
		curr = next;
		if(curr) {
			curr[-1] = ':';
			next = strchr(curr, ':');
			if(next)
				*next++ = 0;
		}
	}

	*pcurr = curr;
	*pnext = next;
}

static char* which(const char* prog, char* buf, size_t buf_size) {
	char* path = getenv("PATH");
	if(!path) return 0;
	while(1) {
		path += strspn(path, ":");
		size_t l = strcspn(path, ":");
		if(!l) break;
		if (snprintf(buf, buf_size, "%.*s/%s", (int)l, path, prog) >= (ssize_t) buf_size)
                        continue;
		if(!access(buf, X_OK)) return buf;
		path += l;
	}
	return 0;
}

static int program_exists_in_path(const char* prog) {
	char buf[256];
	return !!which(prog, buf, sizeof buf);
}

#define PREPROC "manpp"
static int preprocessor_exists(void) {
	return disable_pp ? 0 : program_exists_in_path(PREPROC);
}

static int open_page(char *name) {
	char *p, *command = 0;
	char buf[256];

	if(access(name, 0) < 0)
		return -1;

	if((p = strrchr(name, '.'))) {
		if(!strcmp(p, ".gz")) command = "gzip -dc ";
		else if(!strcmp(p, ".xz")) command = "xzcat -dc ";
	}
	if(!command) command = "cat ";

	snprintf(buf, sizeof buf, "%s%s%s", command, name, preprocessor_exists() ? " | " PREPROC : "");
	if(!(ifd = popen(buf, "r"))) return -1;
	return 0;
}

static void close_page(void) {
	if(ifd) {
		pclose(ifd);
		ifd = 0;
	}
}

/****************************************************************************
 * ifd is the manual page, ofd is the 'output' file or pipe, format it!
 */
static void do_file(void) {
	int nl;
	ungetc('\r', ifd);

	while((nl = fetch_word()) >= 0) {
#ifdef SPLATTER
		fprintf(ofd, ">WS='%s',", whitespace);
		fprintf(ofd, "catmode=%d,", catmode);
		fprintf(ofd, "nl=%d,", nl);
		fprintf(ofd, "no_nl=%d,", no_nl);
		fprintf(ofd, "no_fill=%d,", no_fill);
		fprintf(ofd, "keep_nl=%d,", keep_nl);
		fprintf(ofd, "opt_keep=%d,", optional_keep);
		fprintf(ofd, "WD='%s',", word);
		fprintf(ofd, "\n");
#endif

		if(catmode) {
			if(strcmp(word, "'\\\"") == 0 || strcmp(word, "'''") == 0) {
				/* This is a marker sometimes used for opening subprocesses like
				 * tbl and equ; this program ignores it.
				 */
				do_skipeol();
			} else if(*whitespace == '\r')
				fprintf(ofd, "%s%s", whitespace + 1, word);
			else
				fprintf(ofd, "%s%s", whitespace, word);
		} else {
			if(keep_nl && nl && !no_nl) {
				if(optional_keep) {
					optional_keep = 0;
					if(line_ptr == 0 || next_line_indent < 0 ||
					   left_indent + (line_ptr - line) + 1 > next_line_indent)
						line_break();
					else if(line_ptr != 0 && next_line_indent > 0) {
						while(left_indent + (line_ptr - line) + 1 <= next_line_indent)
							*line_ptr++ = cur_font + ' ';
					}
				} else
					line_break();
				if(keep_nl > 0)
					keep_nl--;
			}

			if(nl == 1 && no_fill)
				line_break();

			if(nl == 1 && (word[0] == '.' ||
				       (word[0] == '\'' && strcmp(word, "'\\\"") == 0) ||
				       (word[0] == '\'' && strcmp(word, "'''") == 0)
			   )) {
				no_nl = 1;
				if(do_command() < 0)
					break;
			} else {
				if(*whitespace)
					print_word(whitespace);
				print_word(word);
				no_nl = 0;
			}
		}
	}

	print_doc_footer();
}

static int fetch_word(void) {
	static int col = 0;
	char *p;
	int ch, nl;

	nl = 0;
	*(p = whitespace) = 0;

	if(!catmode && !no_fill)
		p++;

	while((ch = fgetc(ifd)) != EOF && isspace(ch)) {
		if(ch == '\n') lineno++;
		if(nl && no_fill && ch != '.' && ch != '\n')
			break;
		if(nl && !catmode && ch == '\n') {
			*whitespace = 0;
			strcpy(word, ".sp");
			ungetc(ch, ifd);
			return 1;
		}
		nl = (ch == '\n' || ch == '\r');
		if(nl)
			col = 0;
		else
			col++;

		if(no_fill && nl && *whitespace) {
			*word = 0;
			ungetc(ch, ifd);
			return 0;
		}

		if(p < whitespace + sizeof(whitespace) - 1 && (!nl || catmode))
			*p++ = ch;

		if(ch == '\t' && !catmode) {
			p[-1] = ' ';
			while(col % input_tab) {
				if(p < whitespace + sizeof(whitespace) - 1)
					*p++ = ' ';
				col++;
			}
		}

		if(!catmode && !no_fill && nl)
			*(p = whitespace) = 0;
	}
	*p = 0;

	if(catmode && ch == '.' && nl)
		catmode = 0;

	*(p = word) = 0;
	if(ch == EOF || p > word + sizeof(word) / 2) {
		if(p != word) {
			ungetc(ch, ifd);
			*p = 0;
			return nl;
		}
		return -1;
	}
	ungetc(ch, ifd);

	while((ch = fgetc(ifd)) != EOF && !isspace(ch)) {
		if(p < word + sizeof(word) - 1)
			*p++ = ch;
		col++;
		if(ch == '\\') {
			if((ch = fgetc(ifd)) == EOF)
				break;
			// if( ch == ' ' ) ch = ' ' + 0x80;    /* XXX Is this line needed? */
			if(p < word + sizeof(word) - 1)
				*p++ = ch;
			col++;
		}
	}
	*p = 0;
	ungetc(ch, ifd);

	return (nl != 0);
}

/****************************************************************************
 * Accepted nroff commands and executors.
 */

enum cmd_class {
	CCLASS_NONE = 0,
	CCLASS_PARAMETERED,
	CCLASS_FONTCHANGER,
	CCLASS_SO,
};

static const struct cmd_list_s {
	char cmd[3];
	char class; /* enum cmd_class */
	char id;
} cmd_list[] = {
	{"\\\"", CCLASS_NONE, 0},
	{"nh",   CCLASS_NONE, 0},	/* This program never inserts hyphens */
	{"hy",   CCLASS_NONE, 0},	/* This program never inserts hyphens */
	{"PD",   CCLASS_NONE, 0},	/* Inter-para distance is 1 line */
	{"DT",   CCLASS_NONE, 0},	/* Default tabs, they can't be non-default! */
	{"IX",   CCLASS_NONE, 0},	/* Indexing for some weird package */
	{"Id",   CCLASS_NONE, 0},	/* Line for RCS tokens */
	{"BY",   CCLASS_NONE, 0},	/* I wonder where this should go ? */
	{"nf",   CCLASS_NONE, 1},	/* Line break, Turn line fill off */
	{"fi",   CCLASS_NONE, 2},	/* Line break, Turn line fill on */
	{"sp",   CCLASS_NONE, 3},	/* Line break, line space (arg for Nr lines) */
	{"br",   CCLASS_NONE, 4},	/* Line break */
	{"bp",   CCLASS_NONE, 5},	/* Page break */
	{"PP",   CCLASS_NONE, 6},
	{"LP",   CCLASS_NONE, 6},
	{"P",    CCLASS_NONE, 6},	/* Paragraph */
	{"RS",   CCLASS_NONE, 7},	/* New Para + Indent start */
	{"RE",   CCLASS_NONE, 8},	/* New Para + Indent end */
	{"HP",   CCLASS_NONE, 9},	/* Begin hanging indent (TP without arg?) */
	{"ad",   CCLASS_NONE, 10},	/* Line up right margin */
	{"na",   CCLASS_NONE, 11},	/* Leave right margin unaligned */
	{"ta",   CCLASS_NONE, 12},	/* Changes _input_ tab spacing, right? */
	{"TH",   CCLASS_PARAMETERED, 1},/* Title and headers */
	{"SH",   CCLASS_PARAMETERED, 2},/* Section */
	{"SS",   CCLASS_PARAMETERED, 3},/* Subsection */
	{"IP",   CCLASS_PARAMETERED, 4},/* New para, indent except argument 1 */
	{"TP",   CCLASS_PARAMETERED, 5},/* New para, indent except line 1 */
	{"B",    CCLASS_FONTCHANGER, 22},/* Various font fiddles */
	{"BI",   CCLASS_FONTCHANGER, 23},
	{"BR",   CCLASS_FONTCHANGER, 21},
	{"I",    CCLASS_FONTCHANGER, 33},
	{"IB",   CCLASS_FONTCHANGER, 32},
	{"IR",   CCLASS_FONTCHANGER, 31},
	{"RB",   CCLASS_FONTCHANGER, 12},
	{"RI",   CCLASS_FONTCHANGER, 13},
	{"SB",   CCLASS_FONTCHANGER, 42},
	{"SM",   CCLASS_FONTCHANGER, 44},
	{"C",    CCLASS_FONTCHANGER, 22},/* PH-UX manual pages! */
	{"CI",   CCLASS_FONTCHANGER, 23},
	{"CR",   CCLASS_FONTCHANGER, 21},
	{"IC",   CCLASS_FONTCHANGER, 32},
	{"RC",   CCLASS_FONTCHANGER, 12},
	{"so",   CCLASS_SO, 0},
	{"\0\0", CCLASS_NONE, 0}
};

static int do_command(void) {
	char *cmd;
	int i;
	char lbuf[10];

	cmd = word + 1;

	/* Comments don't need the space */
	if(strncmp(cmd, "\\\"", 2) == 0)
		cmd = "\\\"";

	for(i = 0; cmd_list[i].cmd[0]; i++) {
		if(strcmp(cmd_list[i].cmd, cmd) == 0)
			break;
	}

	if(cmd_list[i].cmd[0] == 0) {
		if(verbose) {
			strncpy(lbuf, cmd, 3);
			lbuf[3] = 0;
			line_break();
			i = left_indent;
			left_indent = 0;
			snprintf(word, sizeof word, "**** Unknown formatter command: .%s @%d", lbuf, lineno);
			print_word(word);
			line_break();
			left_indent = i;
		}

		i = 0;		/* Treat as comment */
	}

	switch (cmd_list[i].class) {
		case CCLASS_PARAMETERED:	/* Parametered commands */
			return do_argvcmd(cmd_list[i].id);

		case CCLASS_FONTCHANGER:	/* Font changers */
			return do_fontwords(cmd_list[i].id / 10, cmd_list[i].id % 10, 0);

		case CCLASS_SO:	/* .so */
			fetch_word();
			if(strlen(man_file) + 4 < sizeof man_file)
				strcat(man_file, word);
			close_page();
			if(find_page(man_file, (char *) 0) < 0) {
				fprintf(stderr, "Cannot open .so file %s\n", word);
				return -1;
			}
			ungetc('\r', ifd);
			break;

		case CCLASS_NONE:
		default:
			do_skipeol();
			if(cmd_list[i].id)
				return do_noargs(cmd_list[i].id);
	}
	return 0;
}

static void do_skipeol(void) {
	int ch;
	char *p = word;

	while((ch = fgetc(ifd)) != EOF && ch != '\n')
		if(p < word + sizeof(word) - 1)
			*p++ = ch;;
	*p = 0;
	ungetc(ch, ifd);
}

static void flush_word(char **p) {
	memcpy(*p, "\\fR", 4);
	print_word(word);
	*p = word;
}

static void insert_font(char **p, int font) {
	const char ftab[] = " RBIS";
	memcpy(*p, "\\f", 2);
	(*p)[2] = ftab[font];
	*p += 3;
}

static int do_fontwords(int this_font, int other_font, int early_exit) {
	char *p = word;
	int ch;
	int in_quote = 0;

	no_nl = 0; /* Line is effectivly been reprocessed so NL is visible */
	for(;;) {
		if(p == word) insert_font(&p, this_font);
		/* at each turn, at most 5 bytes are appended to word
		 * in order to flush the buffer, 4 more bytes are required to stay free */
		if(p+5+4 >= word+sizeof word) {
			assert(p+4<word+sizeof word);
			flush_word(&p);
			continue;
		}
		if((ch = fgetc(ifd)) == EOF || ch == '\n')
			break;
		if(ch == '"') {
			in_quote = !in_quote;
			continue;
		}
		if(in_quote || !isspace(ch)) {
			if(isspace(ch) && p > word + 3) {
				flush_word(&p);
				if(no_fill) print_word(" ");
				continue;
			}
			*p++ = ch;
			if(ch == '\\') {
				if((ch = fgetc(ifd)) == EOF || ch == '\n') break;
				*p++ = ch;
			}
			continue;
		}

		if(p != word + 3) {
			if(early_exit) break;

			if(this_font == other_font) flush_word(&p);
			int i = this_font;
			this_font = other_font;
			other_font = i;
			insert_font(&p, this_font);
		}
	}
	ungetc(ch, ifd);

	if(p > word + 3) flush_word(&p);

	return 0;
}

static int do_noargs(int cmd_id) {
	if(cmd_id < 10)
		line_break();
	switch (cmd_id) {
		case 1:
			no_fill = 1;
			break;
		case 2:
			no_fill = 0;
			break;
		case 3:
			pending_nl = 1;
			break;
		case 4:
			break;
		case 5:
			page_break();
			break;
		case 6:
			left_indent = old_para_indent;
			pending_nl = 1;
			break;
		case 7:
			pending_nl = 1;
			left_indent += standard_tab;
			old_para_indent += standard_tab;
			break;
		case 8:
			pending_nl = 1;
			left_indent -= standard_tab;
			old_para_indent -= standard_tab;
			break;

		case 10:
			right_adjust = 1;
			break;
		case 11:
			right_adjust = 0;
			break;
		case 12:
			input_tab = atoi(word);
			if(input_tab <= 0)
				input_tab = 8;
			break;
	}
	return 0;
}

static int do_argvcmd(int cmd_id) {
	int ch;

	line_break();
	while((ch = fgetc(ifd)) != EOF && (ch == ' ' || ch == '\t')) ;
	ungetc(ch, ifd);

	switch (cmd_id + 10 * (ch == '\n')) {
		case 1:	/* Title and headers */
			page_break();
			left_indent = old_para_indent = standard_tab;
			build_headers();
			break;

		case 2:	/* Section */
			left_indent = 0;
			next_line_indent = old_para_indent = standard_tab;
			no_nl = 0;
			keep_nl = 1;
			pending_nl = 1;

			do_fontwords(2, 2, 0);
			return 0;
		case 3:	/* Subsection */
			left_indent = standard_tab / 2;
			next_line_indent = old_para_indent = standard_tab;
			no_nl = 0;
			keep_nl = 1;
			pending_nl = 1;

			do_fontwords(2, 2, 0);
			break;

		case 15:
		case 5:	/* New para, indent except line 1 */
			do_skipeol();
			next_line_indent = old_para_indent + standard_tab;
			left_indent = old_para_indent;
			pending_nl = 1;
			keep_nl = 1;
			optional_keep = 1;
			break;

		case 4:	/* New para, indent except argument 1 */
			next_line_indent = old_para_indent + standard_tab;
			left_indent = old_para_indent;
			pending_nl = 1;
			keep_nl = 1;
			optional_keep = 1;
			do_fontwords(1, 1, 1);
			do_skipeol();
			break;

		case 14:
			pending_nl = 1;
			left_indent = old_para_indent + standard_tab;
			break;
	}

	return 0;
}

static void build_headers(void) {
	char buffer[5][80];
	int strno = 0;
	unsigned stroff = 0;
	int last_ch = 0, ch, in_quote = 0;

	for(ch = 0; ch < 5; ch++)
		buffer[ch][0] = 0;

	for(;;) {
		if((ch = fgetc(ifd)) == EOF || ch == '\n')
			break;
		if(ch == '"') {
			if(last_ch == '\\') {
				assert(stroff > 0);
				stroff--;
				break;
			}
			in_quote = !in_quote;
			continue;
		}
		last_ch = ch;
		if(in_quote || !isspace(ch)) {
			/* Nb, this does nothing about backslashes, perhaps it should */
			if(stroff < sizeof(buffer[strno]) - 1)
				buffer[strno][stroff++] = ch;
			continue;
		}
		buffer[strno][stroff] = 0;

		if(buffer[strno][0]) {
			strno++;
			stroff = 0;
			if(strno == 5)
				break;
		}
	}
	if(strno < 5)
		buffer[strno][stroff] = 0;
	ungetc(ch, ifd);

	/* Ok we should have upto 5 arguments build the header and footer */

	size_t l0 = strlen(buffer[0]),
	       l1 = strlen(buffer[1]),
	       l2 = strlen(buffer[2]),
	       l3 = strlen(buffer[3]),
	       l4 = strlen(buffer[4]),
	       l01 = l0 + l1 + 2;
	snprintf(line_header, sizeof line_header, "%s(%s)%*s%*s(%s)", buffer[0],
	         buffer[1], (int) (right_margin/2-l01+l4/2+(l4&1)), buffer[4],
	         (int) (right_margin/2-l4/2-l01+l0-(l4&1)), buffer[0], buffer[1]);
	snprintf(doc_footer, sizeof doc_footer, "%s%*s%*s(%s)", buffer[3],
	         (int) (right_margin/2-l3+l2/2+(l2&1)), buffer[2],
	         (int) (right_margin/2-l2/2-l01+l0-(l2&1)), buffer[0], buffer[1]);

	do_skipeol();
}

static void print_word(char *pword) {
/* Eat   \&  \a .. \z and \A .. \Z
 * \fX   Switch to font X (R B I S etc)
 * \(XX  Special character XX
 * \X    Print as X
 */
#define checkw(X) assert(d+X<wword+(sizeof wword/sizeof wword[0]))
#define checkl(X) assert(line_ptr+X<line+(sizeof line/sizeof line[0]))
	char *s;
	int *d, ch = 0;
	int length = 0;
	int wword[256];
	int sp_font = cur_font;

	/* Eat and translate characters. */
	for(s = pword, d = wword; *s; s++) {
		ch = 0;
		if(*s == '\n')
			continue;
		if(*s != '\\') {
			checkw(1);
			*d++ = (ch = *s) + cur_font;
			length++;
		} else {
			if(s[1] == 0)
				break;
			s++;
			if(*s == 'f') {
				if(!is_tty) s++;
				else if(s[1]) {
					static char fnt[] = " RBI";
					char *p = strchr(fnt, *++s);
					if(p == 0)
						cur_font = 0x100;
					else
						cur_font = 0x100 * (p - fnt);
				}
				continue;
			} else if(*s == 's') {
				/* Font size adjusts - strip */
				while(s[1] && strchr("+-0123456789", s[1]))
					s++;
				continue;
			} else if(isalpha(*s) || strchr("!&^[]|~", *s))
				continue;
			else if(*s == '(' || *s == '*') {
			/* XXX Humm character xlate - http://mdocml.bsd.lv/man/mandoc_char.7.html */
				int out = '*';
				if(*s == '*') {
					if(s[1])
						++s;
				} else if(s[1] == 'm' && s[2] == 'i') {
					out = '-';
					s+=2;
					goto K;
				}
				if(s[1])
					++s;
				if(s[1])
					++s;
				K:
				checkw(1);
				*d++ = out + cur_font;
				length++;
				continue;
			}

			checkw(1);
			*d++ = *s + cur_font;
			length++;
		}
	}

	checkw(1);
	*d = 0;
#ifdef SPLATTER
	{
		int *x;
		fprintf(ofd, ">WORD:");
		for(x = wword; *x; x++)
			fputc(*x, ofd);
		fprintf(ofd, ":\n");
	}
#endif

	if(*wword == 0)
		return;

	if(line_ptr)
		if(line_ptr + ((line_ptr[-1] & 0xFF) == '.') - line + length >= right_margin - left_indent) {
			right_adjust = -right_adjust;
			line_break();
		}

	if(line_ptr == 0)
		line_ptr = line;
	else {
		assert(line_ptr > line);
		if(!no_fill && (line_ptr[-1] & 0xFF) > ' ') {
			if((line_ptr[-1] & 0xFF) == '.') {
				checkl(1);
				*line_ptr++ = cur_font + ' ';
			}
			checkl(1);
			*line_ptr++ = sp_font;
			gaps_on_line++;
		}
	}

	checkl(length);
	memcpy(line_ptr, wword, length * sizeof(int));
	line_ptr += length;
#undef checkw
#undef checkl
}

static void line_break(void) {
	int *d, ch;
	int spg = 1, rspg = 1, spgs = 0, gap = 0;

	if(line_ptr == 0)
		return;

	if(current_line == 0)
		print_header();

	if(current_line)
		current_line += 1 + pending_nl;
	for(; pending_nl > 0; pending_nl--)
		fprintf(ofd, "\n");

	if(right_adjust < 0) {
		int over = right_margin - left_indent - (line_ptr - line);
#ifdef SPLATTER
		fprintf(ofd, ">Gaps=%d, Over=%d, ", gaps_on_line, over);
#endif
		if(gaps_on_line && over) {
			spg = rspg = 1 + over / gaps_on_line;
			over = over % gaps_on_line;
			if(over) {
				if(current_line % 2) {
					spgs = over;
					spg++;
				} else {
					spgs = gaps_on_line - over;
					rspg++;
				}
			}
		}
#ifdef SPLATTER
		fprintf(ofd, " (%d,%d) sw=%d\n", spg, rspg, spgs);
#endif
		right_adjust = 1;
	}

	*line_ptr = 0;
	if(*line)
		for(ch = left_indent; ch > 0; ch--)
			fputc(' ', ofd);

	for(d = line; *d; d++) {
		ch = *d;
		if((ch & 0xFF) == 0) {
			int i;
			if(gap++ < spgs)
				i = spg;
			else
				i = rspg;
			for(; i > 0; i--)
				fputc(' ', ofd);
		} else
			switch (ch >> 8) {
				case 2:
					fputc(ch & 0xFF, ofd);
					fputc('\b', ofd);
					fputc(ch & 0xFF, ofd);
					break;
				case 3:
					fputc('_', ofd);
					fputc('\b', ofd);
					fputc(ch & 0xFF, ofd);
					break;
				default:
					fputc(ch & 0xFF, ofd);
					break;
			}
	}
	fputc('\n', ofd);

	line_ptr = 0;

	if(next_line_indent > 0)
		left_indent = next_line_indent;
	next_line_indent = -1;
	gaps_on_line = 0;
}

static void page_break(void) {
	line_break();
}

static void print_header(void) {
	pending_nl = 0;
	if(*line_header) {
		current_line = 1;
		fprintf(ofd, "%s\n\n", line_header);
	}
}

static void print_doc_footer(void) {
	line_break();
	int i;
	for(i = 0; i < 3; i++) fputc('\n', ofd);
	fprintf(ofd, "%s", doc_footer);
}