dc(1)							      General Commands Manual							     dc(1)

NAME

       dc - Provides an interactive desk calculator for arbitrary precision integer arithmetic

SYNOPSIS

       dc

DESCRIPTION

       The  dc command is an arbitrary precision arithmetic calculator.  The dc command takes its input from file or standard input until it reads
       an End-of-File character.  It writes to standard output. The dc command operates on integers by default, but you can specify an input base,
       output base, and a number of fractional digits to be maintained.  The dc command is structured overall as a stacking, reverse Polish calcu-
       lator.

       The bc command is a preprocessor for dc.  It provides infix notation and a syntax similar to the C language, which implements functions and
       reasonable control structures for programs.

SUBCOMMANDS

       Pushes  the  specified  value onto the stack.  number is an unbroken string of the digits 0 to 9.  To specify a negative number, precede it
       with _ (underscore).  A number can contain a decimal point.  Adds (+), subtracts (-), multiplies (*), divides (/), remainders (%), or expo-
       nentiates (^) the top two values on the stack.  The dc command pops the top two entries off the stack and pushes the result on the stack in
       their place.  Interprets the rest of the line as a system command.  Executes a line of input from standard input.   Cleans  the	stack:	dc
       pops  all  values on the stack.	Duplicates the top value on the stack.	Displays all values on the stack.  Pops the top value on the stack
       and uses that value as the number radix for further input.  Pushes the input base on the top of the stack.  Pops the top of the stack,  and
       uses  that value as a nonnegative scale factor.	The appropriate number of places is displayed on output and is maintained during multipli-
       cation, division, and exponentiation. The interaction of scale factor, input base, and  output  base  is  reasonable  if  all  are  changed
       together.   Pushes the value in register x on the stack.  The register x is not changed.  All registers start with zero value.  Treats x as
       a stack and pops its top value onto the main stack.  Pops the top value on the stack and uses that value as the number  radix  for  further
       output.	 Pushes the output base on the top of the stack.  Prints the top value on the stack.  The top value remains unchanged.	Interprets
       the top value on the stack as an ASCII string, prints it, and removes it.  Exits the program.  If dc is executing a  string,  it  pops  the
       recursion  level  by  two.   Pops  the top  value on the stack and the string execution level by that value.  Pops the top of the stack and
       stores it in a register named x, where x can be any single-byte character.  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.  Treats x as a stack.  It pops
       the top of the main stack and pushes that value onto stack x.  Treats the top element of the stack as a character string and executes it as
       a  string  of  dc commands.  Replaces the number on the top of the stack with its scale factor.	Pushes the number of elements in the stack
       onto the stack.	Replaces the top number in the stack with the number of digits in that number.	Puts the bracketed string onto the top	of
       the  stack.  Pops the top two elements of the stack and compares them.  Register x is executed if the stated relationship is TRUE.  dc uses
       these characters for array operations.

EXAMPLES

       To use dc as a calculator proceed as follows:

	      Enter: 1 4 / p	    [Divide 1 by 4]s.

	      The system responds as follows: 0

	      Enter: 1 k  [ Keep 1 decimal place]s.  1 4 / p

	      The system responds as follows: 0.2

	      Enter: 3 k  [ Keep 3 decimal places]s.  1 4 / p

	      The system responds as follows: 0.250

	      Enter: 16 63 5 / + p  [Divide 63 by 5, add the result to 16]s.

	      The system responds as follows: 28.600

	      Enter: 16 63 5 + / p  [Add 63 and 5, divide the result by 16]s.

	      The system responds as follows: 0.235

	      You can type the comments (enclosed in brackets), but they are provided only for your information.

	      When you enter dc expressions directly from the keyboard, press the End-of-File key sequence to end the dc session and return to the
	      shell command line.  To load and run a dc program file, proceed as follows:

	      Enter: dc prog.dc 5 lf x p  [  5 factorial ]s.

	      The system responds as follows: 120

	      Enter: 10 lf x p	[ 10 factorial ]s.

	      The system responds as follows: 3628800

	      This  interprets the dc program saved in prog.dc, then reads from standard input. The lf x evaluates the function stored in register
	      f, which could be defined in the program file prog.dc as:

	      [ f: compute the factorial of n ]s.

	      [    (n = the top of the stack) ]s.

	      [ If 1>n do b;  If 1<n do r ]s.	    [d 1 >b d 1 <r] sf

	      [ Return f(n) = 1   ]s.	    [d - 1 +] sb

	      [ Return f(n) = n * f(n-1)  ]s.	    [d 1 - lf x *] sr

       You can create dc program files with a text editor, or with the -c (compile) flag of the bc command. When you enter dc expressions directly
       from the keyboard, press the End-of-File key sequence to end the dc session and return to the shell command line.

SEE ALSO

       Commands:  bc(1)

																	     dc(1)