units.6

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

.if n .ds / /
.if t .ds / \z/\h'\w'*'u'
.th UNITS VI 8/30/74
.sh NAME
units \*- conversion program
.sh SYNOPSIS
.it Units
converts quantities expressed
in various standard scales to
their equivalents in other scales.
It works interactively in this fashion:
.s3
.it "	You have:"
inch
.br
.it "	You want:"
cm
.br
.it "		* 2.54000e+00
.br
.it "		\*/ 3.93701e\-01
.s3
A quantity is specified as a multiplicative combination of
units optionally preceded by a numeric multiplier.
Powers are indicated by suffixed positive integers,
division by the usual sign:
.s3
.it "	You have:"
15 pounds force/in2
.br
.it "	You want:"
atm
.br
.it "		* 1.02069e+00"
.br
.it "		\*/ 9.79730e\-01"
.s3
.it Units 
only does multiplicative scale changes.
Thus it can convert Kelvin to Rankine, but not Centigrade to
Fahrenheit.
Most familiar units,
abbreviations, and metric prefixes are recognized,
together with a generous leavening of exotica
and a few constants of nature including:
.s3
.nf
	pi	ratio of circumference to diameter
	c	speed of light
	e	charge on an electron
	g	acceleration of gravity 
	force	same as g
	mole	Avogadro's number
	water	pressure head per unit height of water
	au	astronomical unit
.s3
.fi
`Pound' is a unit of
mass.
Compound names are run together, e.g. `lightyear'.
British units that differ from their US counterparts
are prefixed thus: `brgallon'.
For a complete list of units, `cat /usr/lib/units'.
.sh FILES
/usr/lib/units
.sh BUGS