dc(1) DG/UX 5.4R3.00 dc(1)
NAME
dc - desk calculator
SYNOPSIS
dc [ file ]
DESCRIPTION
Dc is an arbitrary precision arithmetic package. Ordinarily it
operates on decimal integers, but you can specify an input base,
output base, and a number of fractional digits to be maintained.
(See bc(1), a preprocessor for dc that provides infix notation and a
C-like syntax that implements functions. bc also provides reasonable
control structures for programs.) 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 and possibly, extended
digits, for radices greater than 10. Extended digits, e.g. A-F
in base 16, must be specified as capital letters only. A
number may be preceded by an underscore () to input a negative
number. Base 10 numbers may contain decimal points.
+ - / * % ^
The top two values on the stack are added ( + ), subtracted ( -
), multiplied (*), or divided (/). The percent sign (%) shows
the remainder when the two values are divided and the caret (^)
shows the result when one of the two numbers is used as an
exponent of the other. 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.
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 at zero. 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. If q is capitalized, the top value on the
stack is popped and the string execution level is popped by
Licensed material--property of copyright holder(s) 1
dc(1) DG/UX 5.4R3.00 dc(1)
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 compared.
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 DG/UX system 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.
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.
; : Used by bc for array operations.
EXAMPLES
$ cat dc.infile1
10sa2sb
lad+p
lalb/p
q
Licensed material--property of copyright holder(s) 2
dc(1) DG/UX 5.4R3.00 dc(1)
$ dc dc.infile1
20
5
$
In this example, the dc command uses dc.infile1 for its input. The
first line of dc.infile1 causes the a and b registers to be loaded
(using "l" for load) with the values 10 and 2, respectively. The
next 2 lines use the a and b register values (using "l" for load
again) to perform some arithmetic. The second line pushes the a
register on the stack, duplicates it and then adds the two numbers
together. The third line pushes the b register and the a register on
the stack and then divides b by a. In both cases the result is
pushed on the stack, and the p causes the result to be printed to the
output file. The 20 is the result of 10+10 and the 5 is the result
of 10/2.
$ cat dc.infile2
[3 5 * p]
x
$ dc dc.infile2
15
<Ctrl-D>
$
In this example, dc.infile2 is used for the input for dc. The first
line of the input pushes the strings of commands onto the stack. The
x command treats the top of the stack as a string of commands and
executes them. The p in the string of commands causes the result
(15) to be written as output. You press Ctrl-D to end execution.
$ cat dc.infile3
[6 4 + p] sa
5
5
=a
q
$ dc dc.infile3
10
$
In this example, dc uses dc.infile3 for its input. The first line of
the input causes register a to be loaded with the given string of
commands ([6 4 + p]). The next two lines cause 2 5s to be pushed on
the stack. The =a command then checks the top 2 values on the stack
to see if they are equal. Since they are, the commands in the a
register are executed. The result (10) is written as output.
DIAGNOSTICS
x is unimplemented X is an octal number.
stack empty Not enough elements on the stack to do what was
Licensed material--property of copyright holder(s) 3
dc(1) DG/UX 5.4R3.00 dc(1)
asked.
Out of space The free list is exhausted (too many digits).
Out of headers Too many numbers being kept around.
Out of pushdown Too many items on the stack.
Nesting Depth Too many levels of nested execution.
SEE ALSO
bc(1).
Licensed material--property of copyright holder(s) 4