What command is typically used to list the files in a directory within a Unix-based system?

In a Unix-based system, the command used to list the files in a directory is "ls." This command is derived from the word "list" and is a fundamental utility for any Unix-like operating system, including Linux and macOS. When executed, "ls" displays the names of files and directories in the current working directory by default. It can also accept various options that modify its behavior, such as displaying additional details like file permissions, sizes, and modification dates.

The other options do not serve this function in a Unix-based environment. "dir" is a command used in DOS and Windows systems to list directory contents but is not native to Unix. "list" and "show" are not standard commands for listing files in any Unix-like system. Instead, they may be used in other contexts or programming languages, but they do not perform the functionality that "ls" does in Unix environments.