How does arithmetic in bash work internally in Linux?

Bash, the Bourne Again SHell, performs arithmetic operations using various methods. Internally, it uses an arithmetic evaluation feature that interprets numbers and performs calculations based on C-like syntax. This allows users to perform basic calculations directly in the command line. Bash also supports integer arithmetic and can handle variables containing integers. However, it is important to note that Bash does not support floating-point arithmetic natively and relies on external tools like `bc` or `awk` for those operations.

To perform arithmetic in Bash, you can use different approaches such as using double parentheses `(( ))`, the `let` command, or even backticks with `$[]` syntax. Here's a simple example using double parentheses to add two numbers: