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units(1)							     units(1)



NAME

  units	- Converts units from one measure to another

SYNOPSIS

  units	[-] [file]

DESCRIPTION

  The units command converts quantities	expressed in one measurement to	their
  equivalents in another.  The units command is	an interactive command.	 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 conver-
  sion is done with a multiplication factor.  For example, units cannot	con-
  vert 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 divi-
  sion 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	exam-
  ple, lightyear).  Prefix British units differing from	their American coun-
  terparts 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:

  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.

  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.

   1.  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 number of
       inches by 2.540000e+00 to get centimeters, and to multiply 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.

   2.  To convert a measurement	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 microseconds, and
       that 1 microsecond equals 6.337753 x 10-15 years.

   3.  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 kilometers.

   4.  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.

   5.  To specify complex units, enter:
	    you	have: gram centimeter/second2
	    you	want: kg-m/sec2

	    * 1.000000e-05
	    / 1.000000e+05

       The units gram centimeter/second2 mean "grams x centimeters/second2."
       Similarly, kg-m/sec2 means "kilograms x meters/sec2," which is often
       read as "kilogram-meters	per seconds squared".

   6.  If the units you	specify	after you have and you want are	incompatible,
       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 convert-
       ing from	one to the other does not make sense.  Therefore, 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	<&lt;Ctrl-d>&gt; causes	you to exit from the units program.

FILES

  /usr/share/lib/units
      Contains units and their conversion values.