Terminal Calculations

Qalculate! is a well known GTK-based GUI calculator. For years I ignored it because I failed to realize that it included a terminal interface, qalc. Since learning about qalc last year it has become my go-to calculator. It supports all the same features as the GUI, including RPN and unit conversions. I primarily use GNU Units for unit wrangling, but being able to perform unit conversions within my calculator is sometimes useful.

$ qalc
> 1EUR to USD
It has been 20 day(s) since the exchange rates last were updated
Do you wish to update the exchange rates now? y

  1 * euro = approx. $1.1137000

> 32oC to oF

  32 * celsius = 89.6 oF

The RPN mode is not quite as intuitive as a purpose built RPN calculator like Orpie, but it is adequate for my uses. My most frequent use of RPN mode is totaling a long list of numbers without bothering with all those tedious + symbols.

> rpn on
> stack
The RPN stack is empty
> 85

  85 = 85

> 42

  42 = 42

> 198

  198 = 198

> 5

  5 = 5

> 659

  659 = 659

> stack

  1:    659
  2:    5
  3:    198
  4:    42
  5:    85

> total

  total([659, 5, 198, 42, 85]) = 989

> stack

  1:    989

Also provided are some basic statistics functions that can help save time.

> mean(2,12,5,3,1)
  mean([2, 12, 5, 3, 1]) = 4.6

And of course there are the varaibles and constants you would expect

> 12+3*8)/2
  (12 + (3 * 8)) / 2 = 18
> ans*pi
  ans * pi = 56.548668

I reach for qalc more frequently than alternative calculators like bc, insect, or the Python shell.