


      DC(1)                       (UNIX 5.0)                      DC(1)



      NAME
           dc - desk calculator

      SYNTAX
           dc [ file ]

      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.

           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 with
                 zero value.  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 that value.



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      DC(1)                       (UNIX 5.0)                      DC(1)



           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 UNIX 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.

           ; :   are used by bc for array operations.




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      DC(1)                       (UNIX 5.0)                      DC(1)



      EXAMPLE
           This example prints the first ten values of n!:

              [la1+dsa*pla10>y]sy
              0sa1
              lyx

      SEE ALSO
           bc(1), which is a preprocessor for dc providing infix
           notation and a C-like syntax which implements functions and
           reasonable control structures for programs.

      DIAGNOSTICS
           x is unimplemented
                where x is an octal number.

           stack empty
                for not enough elements on the stack to do what was
                asked.

           Out of space
                when the free list is exhausted (too many digits).

           Out of headers
                for too many numbers being kept around.

           Out of pushdown
                for too many items on the stack.

           Nesting Depth
                for too many levels of nested execution.
























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