# Parameter Expansion

Shell expands several characters provided in the command line.

* Most important: \*
* Replaced by all files in the current scope.
* Usage: ls \*

What people think that it does: list all files.

What it does: list a list of filenames provided by bash.

* Asterisk is converted to the effective name of the files

```bash
$ ls *
File.txt
$ touch -- '-la’
$ ls
-la file.txt
$ ls *
-rwxr-xr-x 1 user user 455584 Nov 5 23:36 file.txt
```

The **\*** is the last command call that will be expanded to all files and the command will be transformed into `ls -la file.txt`.