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bc

calculatorlinux
The bc command is one of the most frequently used commands in Linux/Unix-like operating systems. bc The bc (basic calculator) is an arbitrary precision calculator language with syntax similar to C. It allows for interactive calculations as well as programming with variables, functions, and control statements.
See ExamplesView Syntax

Quick Reference

Command Name:

bc

Category:

calculator

Platform:

linux

Basic Usage:

bc [options] [arguments]

Common Use Cases

    Syntax

    bc [options] [file...]
bc -l [file...]

    Options

    Option Description
    -h, --help Print a usage message and exit
    -i, --interactive Force interactive mode
    -l, --mathlib Define the standard math library
    -q, --quiet Don't print initial welcome banner
    -s, --standard Process exactly the POSIX bc language
    -w, --warn Give warnings for extensions to POSIX bc
    -v, --version Print version information and exit

    Examples

    How to Use These Examples

    The examples below show common ways to use the bc command. Try them in your terminal to see the results. You can copy any example by clicking on the code block.

    #

    Basic Examples:

    # Launch bc interactively
bc
    # Calculate a simple expression echo "5 + 3" | bc # Output: 8
    # Set decimal precision (scale) echo "scale=4; 10/3" | bc # Output: 3.3333
    # Calculate exponential expressions echo "2^10" | bc # Output: 1024
    # Load math library for additional functions bc -l

    Advanced Examples:

    # Convert from decimal to binary
echo "obase=2; 42" | bc
# Output: 101010
    # Convert from binary to decimal echo "ibase=2; 101010" | bc # Output: 42 # Convert from decimal to hexadecimal echo "obase=16; 255" | bc # Output: FF # Define and use variables bc << EOF a = 5 b = 10 a * b EOF # Output: 50 # Use conditional statements bc << EOF if (10 > 5) { print "True\n" } else { print "False\n" } EOF # Output: True # Define a function to calculate factorial bc << EOF define f(n) { if (n <= 1) return 1 return n * f(n-1) } f(5) EOF # Output: 120 # Calculate square root using math library echo "scale=10; sqrt(2)" | bc -l # Output: 1.4142135623 # Use with loops bc << EOF for (i = 1; i <= 5; i++) { i^2 } EOF # Output: 1\n4\n9\n16\n25

    Try It Yourself

    Practice makes perfect! The best way to learn is by trying these examples on your own system with real files.

    Understanding Syntax

    Pay attention to the syntax coloring: commands, options, and file paths are highlighted differently.

    Notes

    Key Features:

    The bc command provides a powerful calculator language with several key features:

    • Arbitrary precision arithmetic (limited only by available memory)
    • Variables and arrays for storing values
    • User-defined functions and loops for complex calculations
    • Conditional execution with if-else statements
    • Base conversion between different number systems
    • Math library with trigonometric and other advanced functions (when using -l)
    • Interactive and script-friendly operation

    Common Variables and Settings:

    • scale: Determines the number of decimal places in division operations (default is 0)
    • ibase: Sets the input number base (default is 10 for decimal)
    • obase: Sets the output number base (default is 10 for decimal)
    • last or .: Contains the result of the last printed expression

    Math Library Functions (-l option):

    • s(x): sine of x (x in radians)
    • c(x): cosine of x (x in radians)
    • a(x): arctangent of x
    • l(x): natural logarithm of x
    • e(x): exponential function (e^x)
    • j(n,x): Bessel function of integer order n of x
    • sqrt(x): square root of x

    Usage Tips:

    • Initialize variables before using them, otherwise they default to 0
    • Array elements are initialized to 0 and auto-expand as needed
    • Create a ~/.bcrc file to set your preferred scale and other settings
    • Use semicolons to separate multiple expressions on one line
    • For complex scripts, use the here document syntax (bc << EOF) for multi-line input

    Limitations:

    • No support for direct floating point input notation (like 1.5 - must use 1.5 or set scale)
    • Limited error handling compared to modern programming languages
    • No direct support for complex numbers
    • No built-in random number generation

    Related Commands

    These commands are frequently used alongside bc or serve similar purposes:

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    Use Cases

    Learn By Doing

    The best way to learn Linux commands is by practicing. Try out these examples in your terminal to build muscle memory and understand how the bc command works in different scenarios.

    See ExamplesTry Lab Exercises
    $ bc
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