ralcalc is a simple command line calculator designed to take a single line input and produce a result. It is also installed as the "=" command.
For example:
= 2*9
2*9 = 18
Both the input and output make use of SI prefixes (see http://en.wikipedia.org/wiki/SI_prefix ) for easier input and reading of results. Only the common engineering prefixes that are powers a multiple of three are used, so G, M, k, m, u, n, etc.
Numbers can be input using an "e" to indicate a power of ten, so
= 1e-3*1000
1e-3*1000 = 1
ralcalc expects the SI prefixes to be at the end of a number, so 1e-3n is valid but 1ne-3 is not. Basically, I'd avoid mixing the two.
Version information can be shown with:
= -h
ralcalc -h
The -q option causes the input and any error messages to be not printed to the screen.
The -e option causes the result to be displayed in the "1e-3" form rather than with SI prefixes.
The -r option causes the result to be displayed with neither SI prefixes nor exponents.
+ - Addition
- - Subtraction
* x - Multiplication (the 'x' is for use when shell expansion may be a
problem)
/ - Division
^ - Power
[] - Brackets - increase the precedence of anything within the brackets.
() Both sets of brackets are directly equivalent, so = (3+2]/2 is
valid.
_ - The result of the last ralcalc run (stored in $HOME/.ralcalc_result)
= 2^.5
2^.5 = 1.41421
= 1/_
1/_ = 707.107m
The equations are processed in order of ^, * /, + -. Anything within brackets [] is processed first.
This code is licensed under GPL licence. See the COPYING file for more information.
ralcalc was written by Roger Light to fulfill his own needs. He knows that there are other languages that are better suited to this kind of thing, but he isn't really bothered about that.
Updates should be available at http://atchoo.org/tools/ralcalc/ Questions/suggestions should be directed to roger@atchoo.org