Annotation of src/usr.bin/units/units.1, Revision 1.10
1.10 ! aaron 1: .\" $OpenBSD: units.1,v 1.9 1999/06/13 16:31:18 pjanzen Exp $
1.4 deraadt 2: .\" converted to new format by deraadt@openbsd.org
3: .Dd July 14, 1993
4: .Dt UNITS 1
5: .Os
6: .Sh NAME
1.5 deraadt 7: .Nm units
1.4 deraadt 8: .Nd conversion program
9: .Sh SYNOPSIS
1.7 aaron 10: .Nm units
1.4 deraadt 11: .Op Fl f Ar filename
12: .Op Fl q
13: .Op Fl v
1.8 aaron 14: .Ar from-unit
1.4 deraadt 15: .Ar to-unit
16: .Sh DESCRIPTION
1.10 ! aaron 17: The
! 18: .Nm
! 19: program converts quantities expression in various scales to
! 20: their equivalents in other scales.
! 21: The
! 22: .Nm
! 23: program can only handle multiplicative scale changes.
! 24: It cannot convert Celsius
! 25: to Fahrenheit, for example.
! 26: It works interactively by prompting the user for input:
1.4 deraadt 27: .Pp
1.1 deraadt 28: .nf
29: You have: meters
30: You want: feet
31: * 3.2808399
32: / 0.3048
33:
34: You have: cm^3
35: You want: gallons
36: * 0.00026417205
37: / 3785.4118
38: .fi
1.4 deraadt 39: .Pp
1.10 ! aaron 40: The options are as follows:
! 41: .Bl -tag -width Ds
! 42: .It Fl f Ar filename
! 43: Specifies the name of the units data file to load.
! 44: .It Fl q
! 45: Suppresses prompting of the user for units and the display of statistics
! 46: about the number of units loaded.
! 47: .It Fl v
! 48: Prints the version number.
! 49: .It Ar from-unit Ar to-unit
! 50: Allows a single unit conversion to be done directly from the command line.
! 51: No prompting will occur.
! 52: The units program will print out
! 53: only the result of this single conversion.
! 54: .El
! 55: .Pp
1.8 aaron 56: Powers of units can be specified using the
57: .Ql ^
58: character as shown in
59: the example, or by simple concatenation:
1.9 pjanzen 60: .Sq cm3
1.8 aaron 61: is equivalent to
1.9 pjanzen 62: .Sq cm^3 .
1.1 deraadt 63: Multiplication of units can be specified by using spaces, a dash or
1.10 ! aaron 64: an asterisk.
! 65: Division of units is indicated by the slash
1.8 aaron 66: .Pq Ql / .
67: Note that multiplication has a higher precedence than division, so
1.9 pjanzen 68: .Sq m/s/s
1.8 aaron 69: is the same as
1.9 pjanzen 70: .Sq m/s^2
1.8 aaron 71: or
1.9 pjanzen 72: .Sq m/s s .
1.1 deraadt 73: If the user enters incompatible unit types, the units program will
74: print a message indicating that the units are not conformable and
75: it will display the reduced form for each unit:
1.4 deraadt 76: .Pp
1.1 deraadt 77: .nf
78: You have: ergs/hour
1.8 aaron 79: You want: fathoms kg^2 / day
1.1 deraadt 80: conformability error
81: 2.7777778e-11 kg m^2 / sec^3
82: 2.1166667e-05 kg^2 m / sec
83: .fi
1.4 deraadt 84: .Pp
1.10 ! aaron 85: The conversion information is read from a units data file.
! 86: The default file includes definitions for most familiar units,
! 87: abbreviations and metric prefixes.
! 88: Some constants of nature included are:
1.4 deraadt 89: .Bl -tag -width mercury
90: .It pi
91: ratio of circumference to diameter
92: .It c
93: speed of light
94: .It e
95: charge on an electron
96: .It g
97: acceleration of gravity
98: .It force
99: same as g
100: .It mole
101: Avogadro's number
102: .It water
1.9 pjanzen 103: pressure per unit height of water (at 4 C)
1.4 deraadt 104: .It mercury
105: pressure per unit height of mercury
1.9 pjanzen 106: .It ao
107: Bohr radius
108: .It AU
1.4 deraadt 109: astronomical unit
110: .El
111: .Pp
1.9 pjanzen 112: .Sq Pound
1.10 ! aaron 113: is a unit of mass.
! 114: Compound names are run together so
1.9 pjanzen 115: .Sq poundforce
1.10 ! aaron 116: is a unit of force.
! 117: British units that differ from their US counterparts are prefixed with
1.9 pjanzen 118: .Sq br ,
119: and currency is prefixed with its country name:
120: .Sq belgiumfranc ,
121: .Sq britainpound .
122: When searching for
1.1 deraadt 123: a unit, if the specified string does not appear exactly as a unit
1.9 pjanzen 124: name, then the units program will try to remove a trailing
125: .Sq s
126: or a trailing
127: .Sq es
128: and check again for a match.
1.4 deraadt 129: .Pp
1.1 deraadt 130: All of these definitions can be read in the standard units file, or you
1.10 ! aaron 131: can supply your own file.
! 132: A unit is specified on a single line by
! 133: giving its name and an equivalence.
! 134: One should be careful to define
1.1 deraadt 135: new units in terms of old ones so that a reduction leads to the
1.8 aaron 136: primitive units which are marked with
137: .Ql !
138: characters.
1.1 deraadt 139: The units program will not detect infinite loops that could be caused
140: by careless unit definitions.
1.4 deraadt 141: .Pp
1.8 aaron 142: Prefixes are defined in the same way as standard units, but with
1.10 ! aaron 143: a trailing dash at the end of the prefix name.
! 144: Prefixes are applied
1.9 pjanzen 145: after the longest matching unit name is found; for example,
146: .Dq nmile
147: is taken to be a nautical mile rather than a nanomile.
1.4 deraadt 148: .Sh BUGS
1.8 aaron 149: The effect of including a
150: .Ql /
151: in a prefix is surprising.
1.4 deraadt 152: .Pp
1.9 pjanzen 153: Exponents of units entered by the user can be only one digit.
1.1 deraadt 154: You can work around this by multiplying several terms.
1.4 deraadt 155: .Pp
1.10 ! aaron 156: The user must use
! 157: .Ql |
! 158: to indicate division of numbers and
! 159: .Ql /
! 160: to indicate division of symbols.
! 161: This distinction should not be necessary.
1.9 pjanzen 162: .Pp
163: Prefixes specified without a unit are treated as dimensionless quantities.
164: This can lead to confusion when some prefixes are also defined as units
1.10 ! aaron 165: (e.g., m).
! 166: For example, Tera- / Giga- is 1000, but one Tesla (T) is 10,000
1.9 pjanzen 167: Gauss (G).
168: .Pp
169: Some non-SI units have multiple definitions (e.g, barrel, calorie) and
1.10 ! aaron 170: others have changed over time (e.g., cubit).
! 171: In particular, monetary values fluctuate.
1.4 deraadt 172: .Pp
1.1 deraadt 173: The program contains various arbitrary limits on the length
174: of the units converted and on the length of the data file.
1.4 deraadt 175: .Pp
1.1 deraadt 176: The program should use a hash table to store units so that
177: it doesn't take so long to load the units list and check
1.8 aaron 178: for duplication.
1.4 deraadt 179: .Sh FILES
1.1 deraadt 180: /usr/share/misc/units.lib - the standard units library
1.4 deraadt 181: .Sh AUTHOR
1.1 deraadt 182: Adrian Mariano (adrian@cam.cornell.edu or mariano@geom.umn.edu)
![[BACK]](/icons/back.gif){kind=icon}
Return to units.1 CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / units