Practical UNIX

A More Powerful Calculator

bc is an arithmetic utility not limited to just integers:

$ bc
scale=4
8/3
2.6666
2.5 * 4.1/6.25
1.6400
quit
$

In the previous example, you invoke bc and set the scale to 4, meaning that you want it to calculate any fraction to four decimal places. You ask it to calculate 8/3, which gives 2.6666, and then you do a more complex calculation. Note that spaces are optional. Finally, you enter quit to return to the shell prompt. bc can handle addition (+), subtraction (-), multiplication (*), division (/), remainder or modulus (%), and integer exponentiation (^). bc also can accurately compute numbers of any size:

9238472938742937 * 29384729347298472
271470026887302339647844620892264

In addition, bc can be used within backquotes ...