dc - desk calculator
dc is an arbitrary precision arithmetic package. Ordinarily
it operates on decimal integers, but one may specify an
input base, output base, and a number of fractional digits
to be maintained. The overall structure of dc is a stacking
(reverse Polish) calculator. If an argument is given, input
is taken from that file until its end, then from the stan-
bc is a preprocessor for dc that provides infix notation and
a C-like syntax that implements functions. bc also provides
reasonable control structures for programs. See bc(1).
The following constructions are recognized:
The value of the number is pushed on the stack. A
number is an unbroken string of the digits 0-9. It
may be preceded by an underscore (_) to input a nega-
tive number. Numbers may contain decimal points.
+ - / * % ^
The top two values on the stack are added (+), sub-
tracted (-), multiplied (*), divided (/), remaindered
(%), or exponentiated (^). The two entries are popped
off the stack; the result is pushed on the stack in
their place. Any fractional part of an exponent is
sx The top of the stack is popped and stored into a
register named x, where x may be any character. If
the s is capitalized, x is treated as a stack and the
value is pushed on it.
lx The value in register x is pushed on the stack. The
register x is not altered. All registers start with
zero value. If the l is capitalized, register x is
treated as a stack and its top value is popped onto
the main stack.
d The top value on the stack is duplicated.
p The top value on the stack is printed. The top value
P Interprets the top of the stack as an ASCII string,
removes it, and prints it.
f All values on the stack are printed.
q Exits the program. If executing a string, the recur-
sion level is popped by two.
Q Exits the program. The top value on the stack is
popped and the string execution level is popped by
x Treats the top element of the stack as a character
string and executes it as a string of dc commands.
X Replaces the number on the top of the stack with its
[ ... ]
Puts the bracketed ASCII string onto the top of the
<x >x =x
The top two elements of the stack are popped and com-
pared. Register x is evaluated if they obey the stated
v Replaces the top element on the stack by its square
root. Any existing fractional part of the argument
is taken into account, but otherwise the scale factor
! Interprets the rest of the line as a shell command.
c All values on the stack are popped.
i The top value on the stack is popped and used as the
number radix for further input.
I Pushes the input base on the top of the stack.
o The top value on the stack is popped and used as the
number radix for further output.
O Pushes the output base on the top of the stack.
k The top of the stack is popped, and that value is used
as a non-negative scale factor: the appropriate
number of places are printed on output, and main-
tained during multiplication, division, and exponen-
tiation. The interaction of scale factor, input base,
and output base will be reasonable if all are changed
K Pushes the current scale factor on the top of the
z The stack level is pushed onto the stack.
Z Replaces the number on the top of the stack with its
? A line of input is taken from the input source (usu-
ally the terminal) and executed.
Y Displays dc debugging information.
; : are used by bc(1) for array operations.
Example 1: Printing the first ten values of n!
This example prints the first ten values of n!:
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWesu |
x is unimplemented
x is an octal number.
out of space
The free list is exhausted (too many digits).
out of stack space
Too many pushes onto the stack (stack overflow).
Too many pops from the stack (stack underflow).
Too many levels of nested execution.
divide by 0
Division by zero.
sqrt of neg number
Square root of a negative number is not defined (no
exp not an integer
dc only processes integer exponentiation.
exp too big
The largest exponent allowed is 999.
input base is too large
The input base x: 2<= x <= 16.
input base is too small
The input base x: 2<= x <= 16.
output base is too large
The output base must be no larger than BC_BASE_MAX.
invalid scale factor
Scale factor cannot be less than 1.
scale factor is too large
A scale factor cannot be larger than BC_SCALE_MAX.
symbol table overflow
Too many variables have been specified.
Index cannot be less than 1.
index is too large
An index cannot be larger than BC_DIM_MAX.
Man(1) output converted with