bc

bc is an interpreter that supports numbers of arbitrary precision and the interactive execution of statements. The syntax has some similarities to the C programming language. A standard math library is available through command line options. When used, the math library is read in before any other input files. bc then reads in all other files from the command line, evaluating their contents. Then bc reads from standard input (usually the keyboard). The dc program is also included. dc is a calculator that supports reverse-polish notation and allows unlimited precision arithmetic. Macros can also be defined. Normally, dc reads from standard input but can also read in files specified on the command line. A calculator with reverse-polish notation saves numbers to a stack. Arguments to mathematical operations (operands) are "pushed" onto the stack until the next operator is read in, which "pops" its arguments off the stack and "pushes" its results back onto the stack.