dc(1)dc(1)NAMEdc - desk calculator
SYNOPSIS
[file]
DESCRIPTION
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. (See bc(1), a pre‐
processor for that provides infix notation and a C-like syntax that
implements functions. also provides reasonable control structures for
programs.) 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. An end of file on stan‐
dard input or the command stop dc. The following constructions are
recognized:
number The value of the number is pushed on the stack.
A number is an unbroken string of the digits or
It can be preceded by an underscore to input a
negative number. Numbers can 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 and a warning generated. The remainder
is calculated according to the current scale fac‐
tor; it is not the integer modulus function.
yields .1 (one tenth) if scale is 1 because is
2.3 with .1 as the remainder.
The top of the stack is popped and stored into a register named
x, where x can be any character. If the is capi‐
talized, x is treated as a stack and the value is
pushed on it.
The value in register
x is pushed on the stack. Register x is not
altered. All registers start with zero value.
If the is capitalized, register x 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 unchanged. 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. If is capitalized, 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 commands.
replaces the number on the top of the stack with its scale fac‐
tor.
puts the bracketed
ASCII string onto the top of the stack. Strings
can be nested by using nested pairs of brackets.
The top two elements of the stack are popped and
compared.
Register x 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 an
HP-UX system command (unless the
next character is or in which case
appropriate relational operator
above is used).
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 further
output. See below for notes on
output base.
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 interac‐
tion of scale factor, input base,
and output base will be reasonable
if all are changed together.
pushes the 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) and exe‐
cuted.
Used by for array operations.
Generates debugging output for
itself.
The input base may be any number, but only the digits 0-9
and A-F are available for input, thus limiting the use‐
fulness of bases outside the range 1-16. All 16 possible
digits may be used in any base; they always take their
conventional values.
The output base may be any number. Bases in the range of
2-16 generate the "usual" results, with the letters A-F
representing the values from 10 through 16. Bases 0 and
1 generate a string of whose length is the value of the
number. Base −1 generates a similar string consisting of
Other bases have each "digit" represented as a (multi-
digit) decimal number giving the ordinal of that digit.
Each "digit" is signed for negative bases. "Digits" are
separated by spaces. Given the definition of output
base, the command always yields "10" (in a representation
appropriate to the base); yields useful information about
the output base.
DIAGNOSTICS
Where x is an octal number.
There are insufficient elements on the stack to do what
was asked.
The free list is exhausted (too many digits).
Too many numbers are being kept around.
Too many items are on the stack.
There are too many levels of nested execution.
EXAMPLES
This example prints the first ten values of n! (n facto‐
rial):
SEE ALSObc(1).
tutorial in
dc(1)
