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 zero
        value.  If the l is capitalized, register x is treated as



Printed 4/6/89                                                  1

DC(1)                   COMMAND REFERENCE                   DC(1)



        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.

     [ ... ]
        puts the bracketed ASCII string onto the top of the



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DC(1)                   COMMAND REFERENCE                   DC(1)



        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) and sh(1sh).












Printed 4/6/89                                                  3

%%index%%
na:192,72;
sy:264,145;
de:409,2366;3039,2096;5399,16;
ex:5415,235;
di:5650,519;
rv:6169,714;
ca:6883,176;
se:7059,128;
%%index%%000000000152