DC(1) COMMAND REFERENCE DC(1)
NAME
dc - desk calculator
SYNOPSIS
dc [filename]
DESCRIPTION
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
standard input. 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 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.
bc This is a preprocessor for dc providing infix notation
and a C-like syntax which implements functions and
reasonable control structures for programs.
c All values on the stack are popped.
d The top value on the stack is duplicated.
f All values on the stack are printed.
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.
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.
lx The value in register x is pushed on the stack. The
register x is not altered. All registers start with
Printed 10/17/86 1
DC(1) COMMAND REFERENCE DC(1)
zero value. If the l is capitalized, register x is
treated as a stack and its top value is popped onto the
main 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.
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.
q exits the program. If executing a string, the recursion
level is popped by two. If q is capitalized, the top
value on the stack is popped and the string execution
level is popped by that value.
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.
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.
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.
z The stack level is pushed onto the stack.
Z replaces the number on the top of the stack with its
length.
! interprets the rest of the line as a command to be
executed by sh(1sh).
? A line of input is taken from the input source (usually
the terminal) and executed.
; : are used by bc for array operations.
<x >x =x
The top two elements of the stack are popped and
compared. Register x is executed if they obey the
stated relation.
Printed 10/17/86 2
DC(1) COMMAND REFERENCE DC(1)
[ ... ]
puts the bracketed ASCII string onto the top of the
stack.
EXAMPLES
An example which prints the first ten values of n! is
dc
[la1+dsa*pla10>y]sy
0sa1
lyx
q
DIAGNOSTICS
dc : x is unimplemented where x is an octal number.
dc : Stack empty for not enough elements on the stack to do
what was asked.
dc : Out of memory when the free list is exhausted (too many
digits).
Nesting Depth for too many levels of nested execution.
RETURN VALUE
[NO_ERRS] Command completed without error.
[NP_WARN] An error warranting a warning message
occurred. Execution continues.
[P_ERR] A system error occurred. Execution
terminated. See intro(2) for more
information on system errors.
[INTERNAL] An unexpected error occurred. Execution was
terminated. Record the message and save the
core file for analysis. Contact service
personnel at your Tektronix field office.
CAVEATS
If the scale factor is greater than 63, the multiplication
error can be as big as 199.
SEE ALSO
bc(1), sh(1sh).
Printed 10/17/86 3
%%index%%
na:72,56;
sy:128,105;
de:233,2217;2594,2028;4766,121;
ex:4887,220;
di:5107,473;
rv:5580,670;
ca:6250,148;
se:6398,94;
%%index%%000000000151