dc(1) dc(1)NAME dc - desk calculator SYNOPSIS dc [file] DESCRIPTION dc is an arbitrary precision arithmetic package. Ordinarily it operates on decimal integers, but one may specify an in- put 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 stan- dard input. The following constructions are recognized: number Pushes the value of number on the stack. A number is an unbroken string of one or more digits in the range 0-9. It may be preceded by an underscore (_) to indicate a negative number. Numbers may contain decimal points. + - / * % ^ Operate on the top two values on the stack. These are added (+), subtracted (-), multi- plied (*), 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 Pops the top of the stack and stores it into a register named x, where x may be any charac- ter. Sx Pushes the value on x, which is treated as a stack. lx Pushes the value in register x on the stack. The register x is not altered. All registers start with zero value. Lx Pops the top value of register x, which is treated as a stack, onto the main stack. d Duplicates the top value on the stack. p Prints the top value on the stack. The top value remains unchanged. P Interprets the top of the stack as an ASCII string, removes it, and prints it. f Prints all values on the stack. April, 1990 1
dc(1) dc(1)q Exits the program. If executing a string, the recursion level is popped by two. Alternate- ly, CONTROL-d (EOF) will exit from dc. Q Pops the top value on the stack and pops the string execution level by that value. Alter- nately, CONTROL-d (EOF) will exit from dc. x Treats the top element of the stack as a char- acter string and executes it as a string of dc commands. X Replaces the number on the top of the stack with its scale factor. [string] Puts the bracketed ASCII string onto the top of the stack. <x >x =x Pops the top two elements of the stack and compares them. 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 other- wise the scale factor is ignored. ! Interprets the rest of the line as a system command. c Pops all values on the stack. i Pops the top value on the stack and uses it as the number radix for further input. I Pushes the input base on the top of the stack. o Pops the top value on the stack and uses it as the number radix for further output. O Pushes the output base on the top of the stack. k Pops the top of the stack and uses that value as a non-negative scale factor: prints the appropriate number of places on output, and maintains them during multiplication, divi- sion, and exponentiation. The interaction of scale factor, input base, and output base will be reasonable if all are changed together. z Pushes the stack level onto the stack. 2 April, 1990
dc(1) dc(1)Z Replaces the number on the top of the stack with its length. ? Takes a line of input from the input source (usually the terminal) and executes it. ; : Allow bc to perform array operations. EXAMPLES dc 24.2 56.2 + p adds the two numbers and prints the result (top value in the stack). [la1+dsa*pla10>y]sy 0sa1 lyx prints the first ten values of n!. FILES /usr/bin/dc SEE ALSO bc(1). ``dc Reference'' in A/UX Programming Languages and Tools, Volume 2. 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 execu- tion. April, 1990 3