units(1)units(1)NAMEunits - Converts units from one measure to another
SYNOPSISunits [-] [file]
DESCRIPTION
The units command converts quantities expressed in one measurement to
their equivalents in another. The units command is an interactive com‐
mand. It prompts you for the unit you want to convert from and the
unit you want to convert to. The units command does multiplicative
scale changes only. That is, units can convert from one value to
another only when the conversion is done with a multiplication factor.
For example, units cannot convert between degrees Fahrenheit and
degrees Celsius because the value of 32 must be added or subtracted in
the conversion.
You can specify a quantity as a multiplicative combination of units,
optionally preceded by a numeric multiplier.
Indicate powers by entering suffixed positive integers and indicate
division with a / (slash).
The units command recognizes lb as a unit of mass, but considers pound
to be the British pound sterling. Compound names are run together
(for example, lightyear). Prefix British units differing from their
American counterparts with br (for example, brgallon). The
/usr/share/lib/units file contains a complete list of the units that
the units command uses.
Most familiar units, abbreviations, and metric prefixes are recognized
by the units command, together with the following: Ratio of circumfer‐
ence to diameter. Speed of light. Charge on an electron. Accelera‐
tion of gravity. Same as g. Avogadro's number. Pressure head per
unit height of water. Astronomical unit.
The - argument causes units to display a list of all known units and
their conversion values. The file argument specifies an alternative
units file to be used instead of the default file units.
EXAMPLES
To start the units command, enter: units
Now you can try the following examples. To display conversion factors,
enter: you have: in you want: cm
* 2.540000e+00 / 3.937008e-01
The output from the units command tells you to multiply the num‐
ber of inches by 2.540000e+00 to get centimeters, and to multi‐
ply the number of centimeters by 3.937008e-01 to get inches.
These numbers are in standard exponential notation, so
3.937008e-01 means 3.937008 x 10-1, which is the same as
0.3937008. The second number is always the reciprocal of the
first; for example, 2.54 equals 1/0.3937008. To convert a mea‐
surement to different units, enter: you have: 5 years you want:
microsec
* 1.577846e+14 / 6.337753e-15
The output shows that 5 years equals 1.577846 x 1014 microsec‐
onds, and that 1 microsecond equals 6.337753 x 10-15 years. To
give fractions in measurements, enter: you have: 1|3 mi you
want: km
* 5.364480e-01 / 1.864114e+00
The | (vertical bar) indicates division, so 1|3 means one-third.
This shows that one-third mile is the same as 0.536448 kilome‐
ters. To include exponents in measurements, enter: you have:
1.2-5 gal you want: floz
* 1.536000e-03 / 6.510417e+02
The expression 1.2-5 gal is the equivalent of 1.2 x 10-5. Do
not type an e before the exponent. This example shows that 1.2
x 10-5 (0.000012) gallons equal 1.536 x 10-3 (0.001536) fluid
ounces. To specify complex units, enter: you have: gram cen‐
timeter/second2 you want: kg-m/sec2
* 1.000000e-05 / 1.000000e+05
The units gram centimeter/second2 mean "grams x centimeters/sec‐
ond2." Similarly, kg-m/sec2 means "kilograms x meters/sec2,"
which is often read as "kilogram-meters per seconds squared".
If the units you specify after you have and you want are incom‐
patible, enter: you have: ft you want: lb
conformability 3.048000e-01 m 4.535924e-01 kg
The message conformability means the units you specified cannot
be converted. Feet measure length, and pounds measure mass, so
converting from one to the other does not make sense. There‐
fore, the units command displays the equivalent of each value in
standard units.
In other words, this example shows that 1 foot equals 0.3048
meters and that 1 pound equals 0.4535924 kilograms. The units
command shows the equivalents in meters and kilograms because
the command considers these units to be standard measures of
length and mass.
Entering <Ctrl-d> causes you to exit from the units program.
FILES
Contains units and their conversion values.
units(1)
