units - conversion program units [ -v ] [ file ] Units converts quantities expressed in various standard scales to their equivalents in other scales. It works interactively in this fashion: .EX you have: inch you want: cm * 2.54 / 0.393701

A quantity is specified as a multiplicative combination of units and floating point numbers. Operators have the following precedence:

.EX \fL+ \fL- \f1add and subtract \fL* \fL/ \fL× \fL÷ \f1multiply and divide catenation multiply \fL² \fL³ \fL^ \f1exponentiation \fL| \f1divide \fL( ... \fL) \f1grouping

Most familiar units, abbreviations, and metric prefixes are recognized, together with a generous leavening of exotica and a few constants of nature including:

\fL\\$1\ \\$2 \\$3 \\$4 \\$5 \\$6 ..

.fq pi,\f1π ratio of circumference to diameter
.fq c speed of light
.fq e charge on an electron
.fq g acceleration of gravity
.fq force same as \fLg
.fq mole Avogadro's number
.fq water "pressure head per unit height of water"
.fq au astronomical unit

The .L pound is a unit of mass. Compound names are run together, e.g. .LR lightyear . British units that differ from their US counterparts are prefixed thus: .LR brgallon . Currency is denoted .LR belgiumfranc , .LR britainpound , etc.

The complete list of units can be found in /lib/units . A file argument to units specifies a file to be used instead of /lib/units. The -v flag causes units to print its entire database.

.EX you have: 15 pounds force/in² you want: atm * 1.02069 / .97973 /lib/units /sys/src/cmd/units.y Since units does only multiplicative scale changes, it can convert Kelvin to Rankine but not Centigrade to Fahrenheit.

Currency conversions are only as accurate as the last time someone updated the database.