108 lines
2.0 KiB
Plaintext
108 lines
2.0 KiB
Plaintext
.TH UNITS 1
|
||
.if n .ds / /
|
||
.SH NAME
|
||
units \- conversion program
|
||
.SH SYNOPSIS
|
||
.B units
|
||
[
|
||
.B -v
|
||
]
|
||
[
|
||
.I file
|
||
]
|
||
.SH DESCRIPTION
|
||
.I Units
|
||
converts quantities expressed
|
||
in various standard scales to
|
||
their equivalents in other scales.
|
||
It works interactively in this fashion:
|
||
.IP
|
||
.EX
|
||
you have: inch
|
||
you want: cm
|
||
* 2.54
|
||
/ 0.393701
|
||
.EE
|
||
.PP
|
||
A quantity is specified as a multiplicative combination
|
||
of units and floating point numbers.
|
||
Operators have the following precedence:
|
||
.IP
|
||
.EX
|
||
.ta \w'\fLXXXXXXXXXXXXXXX'u
|
||
\fL+\fP \fL-\fP \f1add and subtract
|
||
\fL*\fP \fL/\fP \fL×\fP \fL÷\fP \f1multiply and divide
|
||
catenation multiply
|
||
\fL²\fP \fL³\fP \fL^\fP \f1exponentiation
|
||
\fL|\fP \f1divide
|
||
\fL(\fP ... \fL)\fP \f1grouping
|
||
.EE
|
||
.PP
|
||
Most familiar units,
|
||
abbreviations, and metric prefixes are recognized,
|
||
together with a generous leavening of exotica
|
||
and a few constants of nature including:
|
||
.IP
|
||
.de fq
|
||
\fL\\$1\\fP \\$2 \\$3 \\$4 \\$5 \\$6
|
||
..
|
||
.ta \w'\fLwaterXXX'u
|
||
.nf
|
||
.fq pi,\f1π\fP 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\fP
|
||
.fq mole Avogadro's number
|
||
.fq water "pressure head per unit height of water"
|
||
.fq au astronomical unit
|
||
.fi
|
||
.PP
|
||
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.
|
||
.PP
|
||
The complete list of units can be found in
|
||
.BR /lib/units .
|
||
A
|
||
.I file
|
||
argument to
|
||
.I units
|
||
specifies a file to be used instead of
|
||
.BR /lib/units.
|
||
The
|
||
.B -v
|
||
flag causes
|
||
.I units
|
||
to print its entire database.
|
||
.SH EXAMPLE
|
||
.EX
|
||
you have: 15 pounds force/in²
|
||
you want: atm
|
||
* 1.02069
|
||
/ .97973
|
||
.EE
|
||
.SH FILES
|
||
.B /lib/units
|
||
.SH SOURCE
|
||
.B /sys/src/cmd/units.y
|
||
.SH BUGS
|
||
Since
|
||
.I units
|
||
does only multiplicative scale changes,
|
||
it can convert Kelvin to Rankine but not Centigrade to
|
||
Fahrenheit.
|
||
.PP
|
||
Currency conversions are only as accurate as the last time someone
|
||
updated the database.
|