Annotation of src/usr.bin/units/units.1, Revision 1.15
1.15 ! jmc 1: .\" $OpenBSD: units.1,v 1.14 2003/02/18 07:57:49 jmc Exp $
1.4 deraadt 2: .\" converted to new format by deraadt@openbsd.org
1.14 jmc 3: .\"
4: .\" Copyright (c) 1993 by Adrian Mariano (adrian@cam.cornell.edu)
5: .\"
6: .\" Redistribution and use in source and binary forms, with or without
7: .\" modification, are permitted provided that the following conditions
8: .\" are met:
9: .\" 1. Redistributions of source code must retain the above copyright
10: .\" notice, this list of conditions and the following disclaimer.
11: .\" 2. The name of the author may not be used to endorse or promote products
12: .\" derived from this software without specific prior written permission.
13: .\" Disclaimer: This software is provided by the author "as is". The author
14: .\" shall not be liable for any damages caused in any way by this software.
15: .\"
16: .\" I would appreciate (though I do not require) receiving a copy of any
17: .\" improvements you might make to this program.
1.15 ! jmc 18: .\"
1.4 deraadt 19: .Dd July 14, 1993
20: .Dt UNITS 1
21: .Os
22: .Sh NAME
1.5 deraadt 23: .Nm units
1.4 deraadt 24: .Nd conversion program
25: .Sh SYNOPSIS
1.7 aaron 26: .Nm units
1.4 deraadt 27: .Op Fl f Ar filename
28: .Op Fl q
29: .Op Fl v
1.8 aaron 30: .Ar from-unit
1.4 deraadt 31: .Ar to-unit
32: .Sh DESCRIPTION
1.10 aaron 33: The
34: .Nm
1.11 pjanzen 35: program converts quantities expressed in various scales to
1.10 aaron 36: their equivalents in other scales.
37: The
38: .Nm
39: program can only handle multiplicative scale changes.
40: It cannot convert Celsius
41: to Fahrenheit, for example.
1.11 pjanzen 42: It also does not handle logarithmic units such as bels.
1.10 aaron 43: It works interactively by prompting the user for input:
1.4 deraadt 44: .Pp
1.15 ! jmc 45: .Bd -literal -offset indent
! 46: You have: meters
! 47: You want: feet
! 48: * 3.2808399
! 49: / 0.3048
1.1 deraadt 50:
1.15 ! jmc 51: You have: cm^3
! 52: You want: gallons
! 53: * 0.00026417205
! 54: / 3785.4118
! 55: .Ed
1.13 pjanzen 56: .Pp
57: The
58: .Nm
59: program can handle numbers as well:
60: .Pp
1.15 ! jmc 61: .Bd -literal -offset indent
! 62: You have: 60 miles/hr
! 63: You want: km/hr
! 64: * 96.56064
! 65: / 0.010356187
1.13 pjanzen 66:
1.15 ! jmc 67: You have: 5 austriaschilling
! 68: You want: 100 italylira
! 69: * 7.0357114
! 70: / 0.14213204
! 71: .Ed
1.13 pjanzen 72: .Pp
73: In other words, 60 miles per hour is about 96.6 km/hr, and 5 Austrian
74: Schillings will get you seven 100-Lira coins.
1.4 deraadt 75: .Pp
1.10 aaron 76: The options are as follows:
77: .Bl -tag -width Ds
78: .It Fl f Ar filename
79: Specifies the name of the units data file to load.
80: .It Fl q
81: Suppresses prompting of the user for units and the display of statistics
82: about the number of units loaded.
83: .It Fl v
84: Prints the version number.
85: .It Ar from-unit Ar to-unit
86: Allows a single unit conversion to be done directly from the command line.
87: No prompting will occur.
88: The units program will print out
89: only the result of this single conversion.
90: .El
91: .Pp
1.8 aaron 92: Powers of units can be specified using the
93: .Ql ^
94: character as shown in
95: the example, or by simple concatenation:
1.9 pjanzen 96: .Sq cm3
1.8 aaron 97: is equivalent to
1.9 pjanzen 98: .Sq cm^3 .
1.1 deraadt 99: Multiplication of units can be specified by using spaces, a dash or
1.10 aaron 100: an asterisk.
101: Division of units is indicated by the slash
1.8 aaron 102: .Pq Ql / .
103: Note that multiplication has a higher precedence than division, so
1.9 pjanzen 104: .Sq m/s/s
1.8 aaron 105: is the same as
1.9 pjanzen 106: .Sq m/s^2
1.8 aaron 107: or
1.9 pjanzen 108: .Sq m/s s .
1.1 deraadt 109: If the user enters incompatible unit types, the units program will
110: print a message indicating that the units are not conformable and
111: it will display the reduced form for each unit:
1.4 deraadt 112: .Pp
1.15 ! jmc 113: .Bd -literal -offset indent
! 114: You have: ergs/hour
! 115: You want: fathoms kg^2 / day
! 116: conformability error
! 117: 2.7777778e-11 kg m^2 / sec^3
! 118: 2.1166667e-05 kg^2 m / sec
! 119: .Ed
1.4 deraadt 120: .Pp
1.10 aaron 121: The conversion information is read from a units data file.
122: The default file includes definitions for most familiar units,
123: abbreviations and metric prefixes.
124: Some constants of nature included are:
1.4 deraadt 125: .Bl -tag -width mercury
126: .It pi
127: ratio of circumference to diameter
128: .It c
129: speed of light
130: .It e
131: charge on an electron
132: .It g
133: acceleration of gravity
134: .It force
135: same as g
136: .It mole
137: Avogadro's number
138: .It water
1.9 pjanzen 139: pressure per unit height of water (at 4 C)
1.4 deraadt 140: .It mercury
141: pressure per unit height of mercury
1.9 pjanzen 142: .It ao
143: Bohr radius
144: .It AU
1.4 deraadt 145: astronomical unit
146: .El
147: .Pp
1.9 pjanzen 148: .Sq Pound
1.10 aaron 149: is a unit of mass.
150: Compound names are run together so
1.9 pjanzen 151: .Sq poundforce
1.10 aaron 152: is a unit of force.
153: British units that differ from their US counterparts are prefixed with
1.9 pjanzen 154: .Sq br ,
155: and currency is prefixed with its country name:
156: .Sq belgiumfranc ,
157: .Sq britainpound .
158: When searching for
1.1 deraadt 159: a unit, if the specified string does not appear exactly as a unit
1.9 pjanzen 160: name, then the units program will try to remove a trailing
161: .Sq s
162: or a trailing
163: .Sq es
164: and check again for a match.
1.4 deraadt 165: .Pp
1.1 deraadt 166: All of these definitions can be read in the standard units file, or you
1.10 aaron 167: can supply your own file.
168: A unit is specified on a single line by
169: giving its name and an equivalence.
170: One should be careful to define
1.1 deraadt 171: new units in terms of old ones so that a reduction leads to the
1.8 aaron 172: primitive units which are marked with
173: .Ql !
174: characters.
1.1 deraadt 175: The units program will not detect infinite loops that could be caused
176: by careless unit definitions.
1.4 deraadt 177: .Pp
1.8 aaron 178: Prefixes are defined in the same way as standard units, but with
1.10 aaron 179: a trailing dash at the end of the prefix name.
180: Prefixes are applied
1.9 pjanzen 181: after the longest matching unit name is found; for example,
182: .Dq nmile
183: is taken to be a nautical mile rather than a nanomile.
1.12 aaron 184: .Sh FILES
185: .Bl -tag -width /usr/share/misc/units.lib
186: .It Pa /usr/share/misc/units.lib
187: the standard units library
188: .El
189: .Sh AUTHORS
190: Adrian Mariano (adrian@cam.cornell.edu or mariano@geom.umn.edu)
1.4 deraadt 191: .Sh BUGS
1.8 aaron 192: The effect of including a
193: .Ql /
194: in a prefix is surprising.
1.4 deraadt 195: .Pp
1.9 pjanzen 196: Exponents of units entered by the user can be only one digit.
1.1 deraadt 197: You can work around this by multiplying several terms.
1.4 deraadt 198: .Pp
1.10 aaron 199: The user must use
200: .Ql |
201: to indicate division of numbers and
202: .Ql /
203: to indicate division of symbols.
204: This distinction should not be necessary.
1.9 pjanzen 205: .Pp
206: Prefixes specified without a unit are treated as dimensionless quantities.
207: This can lead to confusion when some prefixes are also defined as units
1.10 aaron 208: (e.g., m).
209: For example, Tera- / Giga- is 1000, but one Tesla (T) is 10,000
1.9 pjanzen 210: Gauss (G).
211: .Pp
212: Some non-SI units have multiple definitions (e.g, barrel, calorie) and
1.10 aaron 213: others have changed over time (e.g., cubit).
214: In particular, monetary values fluctuate.
1.4 deraadt 215: .Pp
1.1 deraadt 216: The program contains various arbitrary limits on the length
217: of the units converted and on the length of the data file.
1.4 deraadt 218: .Pp
1.1 deraadt 219: The program should use a hash table to store units so that
220: it doesn't take so long to load the units list and check
1.8 aaron 221: for duplication.
![[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