DC is a command-line calculator that stands for “Desk Calculator.” It is designed for performing arithmetic calculations with arbitrary precision and follows the Reverse Polish Notation (RPN) methodology. Here are some key points about DC:

**Arbitrary Precision**: DC allows calculations with arbitrary precision, meaning it can handle numbers with a large number of digits without loss of accuracy. This is particularly useful for situations where high precision is required, such as scientific or financial calculations.**Reverse Polish Notation (RPN)**: DC uses a postfix notation called Reverse Polish Notation. In RPN, operators are placed after the operands, which eliminates the need for parentheses and simplifies complex calculations. RPN is known for its efficiency and ease of use once you get accustomed to the notation.**Stack-Based Calculation**: DC operates using a stack-based approach. Numbers and operators are pushed onto a stack, and calculations are performed based on the top elements of the stack. This stack-based paradigm provides flexibility in performing complex calculations, and it allows for easy manipulation of intermediate results.**Command-Line Interface**: DC is primarily used through the command line. Users enter numbers and operators in a specific order, and DC performs the calculations and displays the result. This makes it a lightweight and portable calculator that can be used directly from the terminal without the need for a graphical user interface.**Functionality**: In addition to basic arithmetic operations (addition, subtraction, multiplication, division), DC supports various mathematical functions, such as square roots, exponentiation, trigonometric functions, logarithms, and more. It also allows for defining and using user-defined functions.**Input and Output Formats**: DC accepts input in a plain text format, where each number or operator is separated by whitespace. The result is displayed in a similar format. DC supports both decimal and hexadecimal numbers, allowing for flexible numerical representation.**Availability**: DC is a standard tool available on most Unix-like operating systems, including Linux and macOS. It is often included as part of the core utilities package and can be invoked directly from the command line.

DC provides a powerful and flexible calculator functionality, especially for users who prefer the simplicity and efficiency of the Reverse Polish Notation. With its ability to handle arbitrary precision and a wide range of mathematical functions, DC is suitable for both simple and complex calculations in various fields, including mathematics, engineering, and programming.

## dc command Examples

1. Start an interactive session:

# dc

2. Execute a script:

# dc /path/to/script.dc

3. Calculate an expression with the specified scale:

# dc --expression='10 k 5 3 / p'

4. Calculate 4 times 5 (4 5 *), subtract 17 (17 -), and [p]rint the output:

# dc --expression='4 5 * 17 - p'

5. Set number of decimal places to 7 (7 k), calculate 5 divided by -3 (5 _3 /) and [p]rint:

# dc --expression='7 k 5 _3 / p'

6. Calculate the golden ratio, phi: set number of decimal places to 100 (100 k), square root of 5 (5 v) plus 1 (1 +), divided by 2 (2 /), and [p]rint result:

# dc --expression='100 k 5 v 1 + 2 / p'