Linux Pocket Guide, 2nd Edition

Name

dc — stdin  stdout  - file  -- opt  --help  --version

Synopsis

dc [options] [files]

The dc (desk calculator) command is a reverse-polish notation (RPN), stack-based calculator that reads expressions from standard input and writes results to standard output. If you know how to use a Hewlett-Packard RPN calculator, dc is pretty easy to use once you understand its syntax. But if you’re used to traditional calculators, dc may seem inscrutable. We’ll cover only some basic commands.

For stack and calculator operations:

q	Quit dc.
f	Print the entire stack.
c	Delete (clear) the entire stack.
p	Print the topmost value on the stack.
P	Pop (remove) the topmost value from the stack.
n k	Set precision of future operations to be n decimal places (default is 0: integer operations).

To pop the top two values from the stack, perform a requested operation, and push the result:

+	Addition.
−	Subtraction.
*	Multiplication.
/	Division.
%	Remainder.
^	Exponentiation (second-to-top value is the base, top value is the exponent).

To pop the top value from the stack, perform a requested operation, and push the result:

v	Square root.

Examples:

$ dc
4 5 + p       Print the sum of 4 and 5
9
2 3 ^ p       Raise 2 to the 3rd power and print the result
8
10 * p        Multiply the stack top by 10 and print the result
80
f             Print the stack
80
9
+p            Pop the top two stack values and print their sum
89