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bc(1)

dc(1)




dc(1) dc(1)
NAME dc - desk calculator SYNOPSIS dc [file] ARGUMENTS file Specifies the file from which the input is used. 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. 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. + - / * % ^ Operates on the top two values on the stack. These 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 Pops the top of the stack and stores it in a register named x, where x may be any character. 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. January 1992 1



dc(1) dc(1)
f Prints all values on the stack. q Exits the program. If executing a string, the recursion level is popped by two. Alternately, CONTROL-d (EOF) will exit from dc. Q Pops the top value on the stack and pops the string execution level by that value. Alternately, CONTROL-d (EOF) will exit from dc. 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. [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 otherwise 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, division, 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 January 1992



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. ; : Allows bc to perform array operations. EXAMPLES The command: dc 24.2 56.2 + p adds the two numbers and prints the result (top value in the stack). The command: [la1+dsa*pla10>y]sy 0sa1 lyx prints the first ten values of n!. STATUS MESSAGES AND VALUES x is unimplemented The argument, x, is an octal number. stack empty Not enough elements on the stack to do what was 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. FILES /usr/bin/dc Executable file SEE ALSO bc(1) January 1992 3



dc(1) dc(1)
``dc Reference,'' in A/UX Programming Languages and Tools, Volume 2 4 January 1992

Typewritten Software • bear@typewritten.org • Edmonds, WA 98026