LAB 21: SHELL METACHARACTERS

Type at the prompt:
```
touch ab abc a1 a2 a3 all a12 ba ba.1 ba.2 filex filey AbC ABC ABc2 abc
```
Write and test the command that will:
1. List all files starting with a.
2. List all files ending in at least one digit.
3. List all files not starting with an a or A.
4. List all files ending in a period, followed by a digit.
5. List all files containing just two alphas.
6. List three character files where all letters are uppercase.
7. List files ending in 11 or 12.
8. List files ending in x or y.
9. List all files ending in a digit, an uppercase letter, or a lowercase letter.
10. List all files containing a b.
11. Remove two-character files starting with a.