Demystifying Bash Argument Scope: Why Script and Function Parameters Are Different

Understanding the distinction between script-level and function-level positional parameters is critical for anyone writing Bash scripts, as confusion between them is a frequent source of bugs for beginners. When a function is called with arguments, the $1 inside that function refers to the function's first argument, not the script's—a subtle but crucial difference that often trips up developers. Mastering this concept unlocks proper use of advanced argument-handling techniques like `shift` and `"$@"`, enabling more powerful and maintainable shell scripting.