Add original unix v6

source/s2/units.c

@@ -0,0 +1,456 @@
+#define	NDIM	10
+#define	NTAB	601
+char	*dfile	"/usr/lib/units";
+char	*unames[NDIM];
+double	getflt();
+int	fperr();
+struct unit
+{
+	double	factor;
+	char	dim[NDIM];
+};
+
+struct table
+{
+	double	factor;
+	char	dim[NDIM];
+	char	*name;
+} table[NTAB];
+char	names[NTAB*10];
+struct prefix
+{
+	double	factor;
+	char	*pname;
+} prefix[]
+{
+	1e-18,	"atto",
+	1e-15,	"femto",
+	1e-12,	"pico",
+	1e-9,	"nano",
+	1e-6,	"micro",
+	1e-3,	"milli",
+	1e-2,	"centi",
+	1e-1,	"deci",
+	1e1,	"deka",
+	1e2,	"hecta",
+	1e2,	"hecto",
+	1e3,	"kilo",
+	1e6,	"mega",
+	1e6,	"meg",
+	1e9,	"giga",
+	1e12,	"tera",
+	0.0,	0
+};
+int	ibuf[259];
+int	fperrc;
+int	peekc;
+int	dumpflg;
+
+main(argc, argv)
+char *argv[];
+{
+	register i;
+	register char *file;
+	struct unit u1, u2;
+	double f;
+
+	if(argc>1 && *argv[1]=='-') {
+		argc--;
+		argv++;
+		dumpflg++;
+	}
+	file = dfile;
+	if(argc > 1)
+		file = argv[1];
+	if(fopen(file, ibuf) < 0) {
+		printf("no table\n");
+		exit();
+	}
+	ldfps(07600); /* interrupt on fp errors */
+	signal(8, fperr);
+	init();
+	close(ibuf[0]);
+	ibuf[0] = 0;
+
+loop:
+	fperrc = 0;
+	printf("you have: ");
+	if(convr(&u1))
+		goto loop;
+	if(fperrc)
+		goto fp;
+loop1:
+	printf("you want: ");
+	if(convr(&u2))
+		goto loop1;
+	for(i=0; i<NDIM; i++)
+		if(u1.dim[i] != u2.dim[i])
+			goto conform;
+	f = u1.factor/u2.factor;
+	if(fperrc)
+		goto fp;
+	printf("\t* %e\n", f);
+	printf("\t/ %e\n", 1./f);
+	goto loop;
+
+conform:
+	if(fperrc)
+		goto fp;
+	printf("conformability\n");
+	units(&u1);
+	units(&u2);
+	goto loop;
+
+fp:
+	printf("underflow or overflow\n");
+	goto loop;
+}
+
+units(up)
+struct unit *up;
+{
+	register struct unit *p;
+	register f, i;
+
+	p = up;
+	printf("\t%e ", p->factor);
+	f = 0;
+	for(i=0; i<NDIM; i++)
+		f =| pu(p->dim[i], i, f);
+	if(f&1) {
+		putchar('/');
+		f = 0;
+		for(i=0; i<NDIM; i++)
+			f =| pu(-p->dim[i], i, f);
+	}
+	putchar('\n');
+}
+
+pu(u, i, f)
+{
+
+	if(u > 0) {
+		if(f&2)
+			putchar('-');
+		if(unames[i])
+			printf("%s", unames[i]); else
+			printf("*%c*", i+'a');
+		if(u > 1)
+			putchar(u+'0');
+			return(2);
+	}
+	if(u < 0)
+		return(1);
+	return(0);
+}
+
+convr(up)
+struct unit *up;
+{
+	register struct unit *p;
+	register c;
+	register char *cp;
+	char name[20];
+	int den, err;
+
+	p = up;
+	for(c=0; c<NDIM; c++)
+		p->dim[c] = 0;
+	p->factor = getflt();
+	if(p->factor == 0.)
+		p->factor = 1.0;
+	err = 0;
+	den = 0;
+	cp = name;
+
+loop:
+	switch(c=get()) {
+
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+	case '-':
+	case '/':
+	case ' ':
+	case '\t':
+	case '\n':
+		if(cp != name) {
+			*cp++ = 0;
+			cp = name;
+			err =| lookup(cp, p, den, c);
+		}
+		if(c == '/')
+			den++;
+		if(c == '\n')
+			return(err);
+		goto loop;
+	}
+	*cp++ = c;
+	goto loop;
+}
+
+lookup(name, up, den, c)
+char *name;
+struct unit *up;
+{
+	register struct unit *p;
+	register struct table *q;
+	register i;
+	char *cp1, *cp2;
+	double e;
+
+	p = up;
+	e = 1.0;
+
+loop:
+	q = hash(name);
+	if(q->name) {
+		l1:
+		if(den) {
+			p->factor =/ q->factor*e;
+			for(i=0; i<NDIM; i++)
+				p->dim[i] =- q->dim[i];
+		} else {
+			p->factor =* q->factor*e;
+			for(i=0; i<NDIM; i++)
+				p->dim[i] =+ q->dim[i];
+		}
+		if(c >= '2' && c <= '9') {
+			c--;
+			goto l1;
+		}
+		return(0);
+	}
+	for(i=0; cp1 = prefix[i].pname; i++) {
+		cp2 = name;
+		while(*cp1 == *cp2++)
+			if(*cp1++ == 0) {
+				cp1--;
+				break;
+			}
+		if(*cp1 == 0) {
+			e =* prefix[i].factor;
+			name = cp2-1;
+			goto loop;
+		}
+	}
+	for(cp1 = name; *cp1; cp1++);
+	if(cp1 > name+1 && *--cp1 == 's') {
+		*cp1 = 0;
+		goto loop;
+	}
+	printf("cannot recognize %s\n", name);
+	return(1);
+}
+
+equal(s1, s2)
+char *s1, *s2;
+{
+	register char *c1, *c2;
+
+	c1 = s1;
+	c2 = s2;
+	while(*c1++ == *c2)
+		if(*c2++ == 0)
+			return(1);
+	return(0);
+}
+
+init()
+{
+	register char *cp;
+	register struct table *tp, *lp;
+	int c, i, f, t;
+	char *np;
+
+	cp = names;
+	for(i=0; i<NDIM; i++) {
+		np = cp;
+		*cp++ = '*';
+		*cp++ = i+'a';
+		*cp++ = '*';
+		*cp++ = 0;
+		lp = hash(np);
+		lp->name = np;
+		lp->factor = 1.0;
+		lp->dim[i] = 1;
+	}
+	lp = hash("");
+	lp->name = cp-1;
+	lp->factor = 1.0;
+
+l0:
+	c = get();
+	if(c == 0) {
+		printf("%l units; %l bytes\n\n", i, cp-names);
+		if(dumpflg)
+		for(tp = &table[0]; tp < &table[NTAB]; tp++) {
+			if(tp->name == 0)
+				continue;
+			printf("%s", tp->name);
+			units(tp);
+		}
+		return;
+	}
+	if(c == '/')
+		while(c != '\n')
+			c = get();
+	if(c == '\n')
+		goto l0;
+	np = cp;
+	while(c != ' ' && c != '\t') {
+		*cp++ = c;
+		c = get();
+		if(c == '\n') {
+			*cp++ = 0;
+			tp = hash(np);
+			if(tp->name)
+				goto redef;
+			tp->name = np;
+			tp->factor = lp->factor;
+			for(c=0; c<NDIM; c++)
+				tp->dim[c] = lp->dim[c];
+			i++;
+			goto l0;
+		}
+	}
+	*cp++ = 0;
+	lp = hash(np);
+	if(lp->name)
+		goto redef;
+	convr(lp);
+	lp->name = np;
+	f = 0;
+	i++;
+	if(lp->factor != 1.0)
+		goto l0;
+	for(c=0; c<NDIM; c++) {
+		t = lp->dim[c];
+		if(t>1 || (f>0 && t!=0))
+			goto l0;
+		if(f==0 && t==1) {
+			if(unames[c])
+				goto l0;
+			f = c+1;
+		}
+	}
+	if(f>0)
+		unames[f-1] = np;
+	goto l0;
+
+redef:
+	printf("redefination %s\n", np);
+	goto l0;
+}
+
+double
+getflt()
+{
+	register c, i, dp;
+	double d, e;
+	int f;
+
+	d = 0.;
+	dp = 0;
+	do
+		c = get();
+	while(c == ' ' || c == '\t');
+
+l1:
+	if(c >= '0' && c <= '9') {
+		d = d*10. + c-'0';
+		if(dp)
+			dp++;
+		c = get();
+		goto l1;
+	}
+	if(c == '.') {
+		dp++;
+		c = get();
+		goto l1;
+	}
+	if(dp)
+		dp--;
+	if(c == '+' || c == '-') {
+		f = 0;
+		if(c == '-')
+			f++;
+		i = 0;
+		c = get();
+		while(c >= '0' && c <= '9') {
+			i = i*10 + c-'0';
+			c = get();
+		}
+		if(f)
+			i = -i;
+		dp =- i;
+	}
+	e = 1.;
+	i = dp;
+	if(i < 0)
+		i = -i;
+	while(i--)
+		e =* 10.;
+	if(dp < 0)
+		d =* e; else
+		d =/ e;
+	if(c == '|')
+		return(d/getflt());
+	peekc = c;
+	return(d);
+}
+
+get()
+{
+	register c;
+
+	if(c=peekc) {
+		peekc = 0;
+		return(c);
+	}
+	c = getc(ibuf);
+	if(c <= 0) {
+		if(ibuf[0])
+			return(0);
+		printf("\n");
+		exit();
+	}
+	return(c);
+}
+
+hash(name)
+char *name;
+{
+	register struct table *tp;
+	register char *np;
+	register h;
+
+	h = 0;
+	np = name;
+	while(*np)
+		h = h*57 + *np++ - '0';
+	h = lrem(0, h, NTAB);
+	tp = &table[h];
+l0:
+	if(tp->name == 0)
+		return(tp);
+	if(equal(name, tp->name))
+		return(tp);
+	tp++;
+	if(tp >= &table[NTAB])
+		tp = table;
+	goto l0;
+}
+
+fperr()
+{
+
+	signal(8, fperr);
+	fperrc++;
+}