Manual page for dc(1)
dc - desk calculator
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
is a stacking (reverse Polish) calculator.
If an argument is given,
input is taken from that file until its end,
then from the standard 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
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 negative number. Numbers may
contain decimal points.
- + - / * % ^
The top two values on the stack are added (+), subtracted
(-), 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.
The top of the stack is popped and stored into a register named
may be any character. If the s is capitalized,
is treated as a stack and the value is pushed on it.
The value in register
is pushed on the stack. The register
is not altered. All registers start with zero value. If the l
is capitalized, register
is treated as a stack and its top value is popped onto the main stack.
The top value on the stack is duplicated.
The top value on the stack is printed. The top value remains
Interprets the top of the stack as an ASCII string, removes it,
and prints it.
All values on the stack are printed.
Exits the program. If executing a string, the recursion level is
popped by two.
Exits the program. The top value on the stack is popped and the
string execution level is popped by that value.
Treats the top element of the stack as a character string and executes
it as a string of dc commands.
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 compared. Register
is evaluated if they obey the stated relation.
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.
All values on the stack are popped.
The top value on the stack is popped and used as the number radix
for further input.
Pushes the input base on the top of the stack.
The top value on the stack is popped and used as the number radix for
Pushes the output base on the top of the stack.
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.
Pushes the current scale factor on the top of the stack.
The stack level is pushed onto the stack.
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)
Displays dc debugging information.
- ; :
are used by
for array operations.
This example prints the first ten values of n!:
- x is unimplemented
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).
- empty stack
Too many pops from the stack (stack underflow).
- 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
- invalid scale factor
Scale factor cannot be less than 1.
- scale factor is too large
A scale factor cannot be larger than
- 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
Created by unroff & hp-tools.
© by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97