DC(1)DC(1)NAMEdc - desk calculator
SYNOPSIS
/usr/bin/dc [filename]
/usr/xpg6/bin/dc [filename]
DESCRIPTIONdc 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 struc‐
ture 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‐
dard input.
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).
USAGE
/usr/bin/dc, /usr/xpg6/bin/dc
The following constructions are recognized under both /usr/bin/dc and
/usr/xpg6/bin/dc:
number
The value of the number is pushed on the stack. A number
is an unbroken string of the digits 0−9. It may be pre‐
ceded by an underscore (_) to input a negative number.
Numbers may contain decimal points.
sx
The top of the stack is popped and stored into a regis‐
ter 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 reg‐
ister 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
remains unchanged.
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 recursion
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 that value.
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
scale factor.
[ ... ]
Puts the bracketed ASCII string onto the top of the
stack.
<x >x =x
The top two elements of the stack are popped and com‐
pared. Register x is evaluated if they obey the stated
relation.
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 is
ignored.
!
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 maintained during
multiplication, division, and exponentiation. The
interaction of scale factor, input base, and output
base will be reasonable if all are changed together.
K
Pushes the current scale factor on the top of the stack.
z
The stack level is pushed onto the stack.
Z
Replaces the number on the top of the stack with its
length.
?
A line of input is taken from the input source (usually
the terminal) and executed.
Y
Displays dc debugging information.
; :
Used by bc(1) for array operations.
/usr/bin/dc
The following construction is recognized under /usr/bin/dc, using the
scale of whatever the result is.
+ − / * % ^
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
ignored.
/usr/xpg6/bin/dc
The following construction is recognized under /usr/xpg6/bin/dc. The
results of division are forced to be a scale of 20.
+ − / * % ^
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
ignored.
Ensures that the scale set prior to division is the
scale of the result.
EXAMPLES
Example 1 Printing the first ten values of n!
This example prints the first ten values of n!:
[la1+dsa*pla10>y]sy
0sa1
lyx
SEE ALSObc(1), attributes(5)DIAGNOSTICS
x is unimplemented
x is an octal number.
out of space
The free list is exhausted (too many dig‐
its).
out of stack space
Too many pushes onto the stack (stack
overflow).
empty stack
Too many pops from the stack (stack under‐
flow).
nesting depth
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 imaginary numbers).
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.
invalid index
Index cannot be less than 1.
index is too large
An index cannot be larger than
BC_DIM_MAX.
Aug 29, 2003 DC(1)
