ms2html.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

lower(char *p)
{
	char *x;

	for(x = p; *x; x++)
		if(*x >= 'A' && *x <= 'Z')
			*x -= 'A' - 'a';
	return p;
}

void
g_I(int argc, char **argv)
{
	int anchor;
	char *p;

	anchor = 0;
	if(argc > 2){
		p = argv[2];
		if(p[0] == '(')
		if(p[1] >= '0' && p[1] <= '9')
		if(p[2] == ')'){
			anchor = 1;
			Bprint(&bout, "<A href=\"/magic/man2html/%c/%s\">",
				p[1], lower(argv[1]));
		}
	}
	font(&ifont, argc, argv);
	if(anchor)
		Bprint(&bout, "</A>");
}

void
g_br(int, char**)
{
	if(hangingdt){
		Bprint(&bout, "<dd>");
		hangingdt = 0;
	}else
		Bprint(&bout, "<br>\n");
}

void
g_P1(int, char**)
{
	if(example == 0){
		example = 1;
		Bprint(&bout, "<DL><DT><DD><TT><PRE>\n");
	}
}

void
g_P2(int, char**)
{
	if(example){
		example = 0;
		Bprint(&bout, "</PRE></TT></DL>\n");
	}
}

void
g_SM(int, char **argv)
{
	Bprint(&bout, "%s", argv[1]);
}

void
g_ft(int argc, char **argv)
{
	if(argc < 2){
		pushfont(nil);
		return;
	}

	switch(argv[1][0]){
	case '3':
	case 'B':
		pushfont(&bfont);
		break;
	case '2':
	case 'I':
		pushfont(&ifont);
		break;
	case '4':
		pushfont(&bifont);
		break;
	case '5':
		pushfont(&cwfont);
		break;
	case 'P':
		popfont();
		break;
	case 'R':
	default:
		pushfont(nil);
		break;
	}
}

void
g_sp(int argc, char **argv)
{
	int n;

	n = 1;
	if(argc > 1){
		n = atoi(argv[1]);
		if(n < 1)
			n = 1;
		if(argv[1][strlen(argv[1])-1] == 'i')
			n *= 4;
	}
	if(n > 5){
		Bprint(&bout, "<br>&#32;<br>\n");
		Bprint(&bout, "<HR>\n");
		Bprint(&bout, "<br>&#32;<br>\n");
	} else
		for(; n > 0; n--)
			Bprint(&bout, "<br>&#32;<br>\n");
}

 void
rm_loop(char *name, String **l)
{
	String *s;
	for(s = *l; s != nil; s = *l){
		if(strcmp(name, s->name) == 0){
			*l = s->next;
			free(s->name);
			free(s->val);
			free(s);
			break;
			}
		l = &s->next;
		}
	}

void
g_rm(int argc, char **argv)
{
	Goobie *g;
	char *name;
	int i;

	for(i = 1; i < argc; i++) {
		name = argv[i];
		rm_loop(name, &strings);
		rm_loop(name, &macros);
		for(g = gtab; g->name; g++)
			if (strcmp(g->name, name) == 0) {
				g->f = g_ignore;
				break;
				}
		}
	}

void
g_AB(int, char**)
{
	closel();
	dohangingcenter();
	Bprint(&bout, "<center><H4>ABSTRACT</H4></center><DL><DD>\n");
}

void
g_AE(int, char**)
{
	Bprint(&bout, "</DL>\n");
}

void
g_FS(int, char **)
{
	char *argv[3];

	argv[0] = "IP";
	argv[1] = nil;
	argv[2] = nil;
	g_IP(1, argv);
	Bprint(&bout, "NOTE:<I> ");
}

void
g_FE(int, char **)
{
	Bprint(&bout, "</I><DT>&#32;<DD>");
	closel();
	Bprint(&bout, "<br>\n");
}

void
g_de(int argc, char **argv)
{
	int r;
	char *p, *cp;
	String *m;
	int len;

	if(argc < 2)
		return;

	m = nil;
	len = 0;
	if(strcmp(argv[0], "am") == 0){
		for(m = macros; m != nil; m = m->next)
			if(strcmp(argv[1], m->name) == 0){
				len = strlen(m->val);
				break;
			}

		if(m == nil){
			/* nothing to append to */
			for(;;){
				p = Brdline(&ssp->in, '\n');
				if(p == nil)
					break;
				p[Blinelen(&ssp->in)-1] = 0;
				if(strcmp(p, "..") == 0)
					break;
			}
			return;
		}
	}

	if(m == nil){
		m = emalloc(sizeof(*m));
		m->next = macros;
		macros = m;
		m->name = strdup(argv[1]);
		m->val = nil;
		len = 0;
	}

	/* read up to a .. removing double backslashes */
	for(;;){
		p = Brdline(&ssp->in, '\n');
		if(p == nil)
			break;
		p[Blinelen(&ssp->in)-1] = 0;
		if(strcmp(p, "..") == 0)
			break;
		m->val = realloc(m->val, len + Blinelen(&ssp->in)+1);
		cp = m->val + len;
		while(*p){
			r = *p++;
			if(r == '\\' && *p == '\\')
				p++;
			*cp++ = r;
		}
		*cp++ = '\n';
		len = cp - m->val;
		*cp = 0;
	}
}

void
g_hrule(int, char**)
{
	Bprint(&bout, "<HR>\n");
}

void
g_BX(int argc, char **argv)
{
	Bprint(&bout, "<HR>\n");
	printargs(argc, argv);
	Bprint(&bout, "<HR>\n");
}

void
g_IH(int, char**)
{
	Bprint(&bout, "Bell Laboratories, Naperville, Illinois, 60540\n");
}

void
g_MH(int, char**)
{
	Bprint(&bout, "Bell Laboratories, Murray Hill, NJ, 07974\n");
}

void
g_PY(int, char**)
{
	Bprint(&bout, "Bell Laboratories, Piscataway, NJ, 08854\n");
}

void
g_HO(int, char**)
{
	Bprint(&bout, "Bell Laboratories, Holmdel, NJ, 07733\n");
}

void
g_QS(int, char**)
{
	Bprint(&bout, "<BLOCKQUOTE>\n");
}

void
g_QE(int, char**)
{
	Bprint(&bout, "</BLOCKQUOTE>\n");
}

void
g_RS(int, char**)
{
	Bprint(&bout, "<DL><DD>\n");
}

void
g_RE(int, char**)
{
	Bprint(&bout, "</DL>\n");
}

int gif;

void
g_startgif(int, char **argv)
{
	int fd;
	int pfd[2];
	char *e, *p;
	char name[32];
	Dir *d;

	if(strcmp(argv[0], "EQ") == 0)
		e = ".EN";
	else if(strcmp(argv[0], "TS") == 0)
		e = ".TE";
	else if(strcmp(argv[0], "PS") == 0)
		e = ".PE";
	else
		return;

	if(basename)
		p = basename;
	else{
		p = strrchr(sstack[0].filename, '/');
		if(p != nil)
			p++;
		else
			p = sstack[0].filename;
	}
	snprint(name, sizeof(name), "%s.%d.gif", p, gif++);
	fd = create(name, OWRITE, 0664);
	if(fd < 0){
		fprint(2, "ms2html: can't create %s: %r\n", name);
		return;
	}

	if(pipe(pfd) < 0){
		fprint(2, "ms2html: can't create pipe: %r\n");
		close(fd);
		return;
	}
	switch(rfork(RFFDG|RFPROC)){
	case -1:
		fprint(2, "ms2html: can't fork: %r\n");
		close(fd);
		return;
	case 0:
		dup(fd, 1);
		close(fd);
		dup(pfd[0], 0);
		close(pfd[0]);
		close(pfd[1]);
		execl("/bin/troff2gif", "troff2gif", nil);
		fprint(2, "ms2html: couldn't exec troff2gif: %r\n");
		_exits(nil);
	default:
		close(fd);
		close(pfd[0]);
		fprint(pfd[1], ".ll 7i\n");
	/*	fprint(pfd[1], ".EQ\ndelim %s\n.EN\n", delim); */
	/*	fprint(pfd[1], ".%s\n", argv[0]); */
		for(;;){
			p = Brdline(&ssp->in, '\n');
			if(p == nil)
				break;
			ssp->lno++;
			ssp->rlno++;
			if(write(pfd[1], p, Blinelen(&ssp->in)) < 0)
				break;
			if(strncmp(p, e, 3) == 0)
				break;
		}
		close(pfd[1]);
		waitpid();
		d = dirstat(name);
		if(d == nil)
			break;
		if(d->length == 0){
			remove(name);
			free(d);
			break;
		}
		free(d);
		fprint(2, "ms2html: created auxiliary file %s\n", name);
		Bprint(&bout, "<br><img src=\"%s\"><br>\n", name);
		break;
	}
}

void
g_lf(int argc, char **argv)
{
	if(argc > 2)
		snprint(ssp->filename, sizeof(ssp->filename), argv[2]);
	if(argc > 1)
		ssp->rlno = atoi(argv[1]);
}

void
g_so(int argc, char **argv)
{
	ssp->lno++;
	ssp->rlno++;
	if(argc > 1)
		pushsrc(argv[1]);
}


void
g_BP(int argc, char **argv)
{
	int fd;
	char *p, *ext;
	char name[32];
	Dir *d;

	if(argc < 2)
		return;

	p = strrchr(argv[1], '/');
	if(p != nil)
		p++;
	else
		p = argv[1];


	ext = strrchr(p, '.');
	if(ext){
		if(strcmp(ext, ".jpeg") == 0
		|| strcmp(ext, ".gif") == 0){
			Bprint(&bout, "<br><img src=\"%s\"><br>\n", argv[1]);
			return;
		}
	}


	snprint(name, sizeof(name), "%s.%d%d.gif", p, getpid(), gif++);
	fd = create(name, OWRITE, 0664);
	if(fd < 0){
		fprint(2, "ms2html: can't create %s: %r\n", name);
		return;
	}

	switch(rfork(RFFDG|RFPROC)){
	case -1:
		fprint(2, "ms2html: can't fork: %r\n");
		close(fd);
		return;
	case 0:
		dup(fd, 1);
		close(fd);
		execl("/bin/ps2gif", "ps2gif", argv[1], nil);
		fprint(2, "ms2html: couldn't exec ps2gif: %r\n");
		_exits(nil);
	default:
		close(fd);
		waitpid();
		d = dirstat(name);
		if(d == nil)
			break;
		if(d->length == 0){
			remove(name);
			free(d);
			break;
		}
		free(d);
		fprint(2, "ms2html: created auxiliary file %s\n", name);
		Bprint(&bout, "<br><img src=\"%s\"><br>\n", name);
		break;
	}
}

/* insert straight HTML into output */
void
g__H(int argc, char **argv)
{
	int i;

	for(i = 1; i < argc; i++)
		Bprint(&bout, "%s ", argv[i]);
	Bprint(&bout, "\n");
}

/* HTML page title */
void
g__T(int argc, char **argv)
{
	if(titleseen)
		return;

	Bprint(&bout, "<title>\n");
	printargs(argc, argv);
	Bprint(&bout, "</title></head><body>\n");
	titleseen = 1;
}

void
g_nr(int argc, char **argv)
{
	char *val;

	if (argc > 1) {
		if (argc == 2)
			val = "0";
		else
			val = argv[2];
		dsnr(argv[1], val, &numregs);
	}
}

void
zerodivide(void)
{
	fprint(2, "stdin %d(%s:%d): division by 0\n",
		ssp->lno, ssp->filename, ssp->rlno);
}

int
numval(char **pline, int recur)
{
	char *p;
	int neg, x, y;

	x = neg = 0;
	p = *pline;
	while(*p == '-') {
		neg = 1 - neg;
		p++;
	}
	if (*p == '(') {
		p++;
		x = numval(&p, 1);
		if (*p != ')')
			goto done;
		p++;
	}
	else while(*p >= '0' && *p <= '9')
		x = 10*x + *p++ - '0';
	if (neg)
		x = -x;
	if (recur)
	    for(;;) {
		switch(*p++) {
		case '+':
			x += numval(&p, 0);
			continue;
		case '-':
			x -= numval(&p, 0);
			continue;
		case '*':
			x *= numval(&p, 0);
			continue;
		case '/':
			y = numval(&p, 0);
			if (y == 0) {
				zerodivide();
				x = 0;
				goto done;
			}
			x /= y;
			continue;
		case '<':
			if (*p == '=') {
				p++;
				x = x <= numval(&p, 0);
				continue;
			}
			x = x < numval(&p, 0);
			continue;
		case '>':
			if (*p == '=') {
				p++;
				x = x >= numval(&p, 0);
				continue;
			}
			x = x > numval(&p, 0);
			continue;
		case '=':
			if (*p == '=')
				p++;
			x = x == numval(&p, 0);
			continue;
		case '&':
			x &= numval(&p, 0);
			continue;
		case ':':
			x |= numval(&p, 0);
			continue;
		case '%':
			y = numval(&p, 0);
			if (!y) {
				zerodivide();
				goto done;
			}
			x %= y;
			continue;
		}
		--p;
		break;
	}
 done:
	*pline = p;
	return x;
}

int
iftest(char *p, char **bp)
{
	char *p1;
	int c, neg, rv;

	rv = neg = 0;
	if (*p == '!') {
		neg = 1;
		p++;
	}
	c = *p;
	if (c >= '0' && c <= '9' || c == '+' || c == '-' || c == '('/*)*/) {
		if (numval(&p,1) >= 1)
			rv = 1;
		goto done;
	}
	switch(c) {
	case 't':
	case 'o':
		rv = 1;
	case 'n':
	case 'e':
		p++;
		goto done;
	}
	for(p1 = ++p; *p != c; p++)
		if (!*p)
			goto done;
	for(p++;;) {
		if (*p != *p1++) {
			while(*p && *p++ != c);
			goto done;
		}
		if (*p++ == c)
			break;
	}
	rv = 1;
 done:
	if (neg)
		rv = 1 - rv;
	while(*p == ' ' || *p == '\t')
		p++;
	*bp = p;
	return rv;
}

void
scanline(char *p, char *e, int wantnl)
{
	int c;
	Rune r;

	while((c = getrune()) == ' ' || c == '\t') ;
	while(p < e) {
		if (c < 0)
			break;
		if (c < Runeself) {
			if (c == '\n') {
				if (wantnl)
					*p++ = c;
				break;
			}
			*p++ = c;
		}
		else {
			r = c;
			p += runetochar(p, &r);
		}
		c = getrune();
	}
	*p = 0;
}

void
pushbody(char *line)
{
	char *b;

	if (line[0] == '\\' && line[1] == '{' /*}*/ )
		line += 2;
	if (strsp < Maxmstack - 1) {
		pushstr(b = strdup(line));
		mustfree[strsp] = b;
	}
}

void
skipbody(char *line)
{
	int c, n;

	if (line[0] != '\\' || line[1] != '{' /*}*/ )
		return;
	for(n = 1;;) {
		while((c = getrune()) != '\\')
			if (c < 0)
				return;
		c = getrune();
		if (c == '{')
			n++;
		else if ((c == '}' && (c = getrune()) == '\n' && !--n)
			|| c < 0)
			return;
	}
}

int
ifstart(char *line, char *e, char **bp)
{
	int it;
	char *b;

	b = copyline(line, e, 1);
	ungetrune();
	b[-1] = getrune();
	scanline(b, e, 1);
	it = iftest(line, bp);
	return it;
}

void
g_ie(char *line, char *e)
{
	char *b;

	if (elsetop >= Maxif-1) {
		fprint(2, "ms2html: .ie's too deep\n");
		return;
	}
	if (ifwastrue[++elsetop] = ifstart(line, e, &b))
		pushbody(b);
	else
		skipbody(b);
}

void
g_if(char *line, char *e)
{
	char *b;

	if (ifstart(line, e, &b))
		pushbody(b);
	else
		skipbody(b);
}

void
g_el(char *line, char *e)
{
	if (elsetop < 0)
		return;
	scanline(line, e, 1);
	if (ifwastrue[elsetop--])
		skipbody(line);
	else
		pushbody(line);
}

void
g_ig(int argc, char **argv)
{
	char *p, *s;

	s = "..";
	if (argc > 1)
		s = argv[1];
	for(;;) {
		p = Brdline(&ssp->in, '\n');
		if(p == nil)
			break;
		p[Blinelen(&ssp->in)-1] = 0;
		if(strcmp(p, s) == 0)
			break;
	}
}

void
g_ds(char *line, char *e)
{
	char *b;

	b = copyline(line, e, 1);
	if (b > line) {
		copyline(b, e, 0);
		if (*b == '"')
			b++;
		ds(line, b);
	}
}

void
g_as(char *line, char *e)
{
	String *s;
	char *b;

	b = copyline(line, e, 1);
	if (b == line)
		return;
	copyline(b, e, 0);
	if (*b == '"')
		b++;
	for(s = strings; s != nil; s = s->next)
		if(strcmp(line, s->name) == 0)
			break;

	if(s == nil){
		ds(line, b);
		return;
	}

	s->val = realloc(s->val, strlen(s->val) + strlen(b) + 1);
	strcat(s->val, b);
}

void
g_BS(int argc, char **argv)
{
	int i;

	if (argc > 1 && !weBref) {
		Bprint(&bout, "<a href=\"%s\"", argv[1]);
		for(i = 2; i < argc; i++)
			Bprint(&bout, " %s", argv[i]);
		Bprint(&bout, ">");
		weBref = 1;
	}
}

void
g_BE(int, char**)
{
	if (weBref) {
		Bprint(&bout, "</a>");
		weBref = 0;
	}
}

void
g_LB(int argc, char **argv)
{
	if (argc > 1) {
		if (weBref)
			g_BE(0,nil);
		Bprint(&bout, "<a name=\"%s\"></a>", argv[1]);
	}
}

void
g_RT(int, char**)
{
	g_BE(0,nil);
	dohanginghead();
	closel();
	closefont();
}