dc

Start interactive calculator

$ dc

$ echo "[5 3 + p]" | dc

$ echo "[4 7 * p]" | dc

$ echo "[10 k 22 7 / p]" | dc

$ dc [script.dc]

$ echo "[5 sa la 3 + p]" | dc

$ echo "[5 [d 1 - d 1 <f *] d sf x p]" | dc

dc [options] [file...]

dc is an arbitrary precision desk calculator using reverse Polish notation (RPN). Numbers and operators are entered sequentially, with operators acting on values in a stack. It supports arithmetic, comparisons, and programmable macros.
Basic operations push numbers onto the stack and apply operators: 5 3 + pushes 5 and 3, then adds them. The p command prints the top of stack. The k command sets decimal precision for division and other operations.
dc provides registers (a-z) for storing values, conditional execution, loops through macros, and string manipulation. Despite its terse syntax, it can implement complex algorithms including recursion.

FILE

File containing dc commands to execute.

Evaluate expression from command line.

Read commands from file.

Display help information.

Display version information.

RPN syntax can be unintuitive for users accustomed to infix notation. Error messages are minimal. Complex programs are difficult to read and debug. Some extended features vary between implementations.

dc is one of the oldest Unix utilities, written by Robert Morris at Bell Labs around 1969-1971. It predates the C programming language and was originally implemented in B. The bc calculator was later written as a preprocessor for dc.

bc(1), calc(1), expr(1)