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diff --git a/usr.bin/units/units.1 b/usr.bin/units/units.1 new file mode 100644 index 0000000..8916052 --- /dev/null +++ b/usr.bin/units/units.1 @@ -0,0 +1,124 @@ +.\" $Id: units.1,v 1.6 1996/04/06 06:01:02 thorpej Exp $ +.TH UNITS 1 "14 July 1993" +.SH NAME +units - conversion program +.SH SYNTAX +.B units +[-f filename] [-qv] [from-unit to-unit] +.SH SUMMARY +.TP 4 +.B -f filename +Specifies the name of the units data file to load. +.LP +.TP 4 +.B -q +Suppresses prompting of the user for units and the display of statistics +about the number of units loaded. +.LP +.TP 4 +.B -v +Prints the version number. +.LP +.TP 4 +.B from-unit to-unit +Allows a single unit conversion to be done directly from the command +line. No prompting will occur. The units program will print out +only the result of this single conversion. + +.SH DESCRIPTION +The units program converts quantities expression in various scales to +their equivalents in other scales. The units program can only +handle multiplicative scale changes. It cannot convert Centigrade +to Fahrenheit, for example. It works interactively by prompting +the user for input: +.nf + + You have: meters + You want: feet + * 3.2808399 + / 0.3048 + + You have: cm^3 + You want: gallons + * 0.00026417205 + / 3785.4118 + +.fi +Powers of units can be specified using the '^' character as shown in +the example, or by simple concatenation: 'cm3' is equivalent to 'cm^3'. +Multiplication of units can be specified by using spaces, a dash or +an asterisk. Division of units is indicated by the slash ('/'). +Note that multiplication has a higher precedence than division, +so 'm/s/s' is the same as 'm/s^2' or 'm/s s'. +If the user enters incompatible unit types, the units program will +print a message indicating that the units are not conformable and +it will display the reduced form for each unit: +.nf + + You have: ergs/hour + You want: fathoms kg^2 / day + conformability error + 2.7777778e-11 kg m^2 / sec^3 + 2.1166667e-05 kg^2 m / sec + +.fi +.LP +The conversion information is read from a units data file. The default +file includes definitions for most familiar units, abbreviations and +metric prefixes. Some constants of nature included are: +.in +4m +.ta +.ta 9m + +.nf + +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 per unit height of water +mercury pressure per unit height of mercury +au astronomical unit + +.fi +.in -4m +\'Pound' is a unit of mass. Compound names are run together +so 'poundforce' is a unit of force. British units that differ from their +US counterparts are prefixed with 'br', and currency is prefixed with +its country name: 'belgiumfranc', 'britainpound'. When searching for +a unit, if the specified string does not appear exactly as a unit +name, then the units program will try to remove a trailing 's' or +a trailing 'es' and check again for a match. +.LP +All of these definitions can be read in the standard units file, or you +can supply your own file. A unit is specified on a single line by +giving its name and an equivalence. One should be careful to define +new units in terms of old ones so that a reduction leads to the +primitive units which are marked with '!' characters. +The units program will not detect infinite loops that could be caused +by careless unit definitions. +.LP +Prefixes are defined in the same was as standard units, but with +a trailing dash at the end of the prefix name. +.SH BUGS +.LP +The effect of including a '/' in a prefix is surprising. +.LP +Exponents entered by the user can be only one digit. +You can work around this by multiplying several terms. +.LP +The user must use | to indicate division of numbers and / to +indicate division of symbols. This distinction should not +be necessary. +.LP +The program contains various arbitrary limits on the length +of the units converted and on the length of the data file. +.LP +The program should use a hash table to store units so that +it doesn't take so long to load the units list and check +for duplication. +.SH FILES +/usr/share/misc/units.lib - the standard units library +.SH AUTHOR +Adrian Mariano (adrian@cam.cornell.edu or mariano@geom.umn.edu) |
