Rust Taskbook Level 8.2

Задание 1

Given a text file, get the number of letters in it (i.e. without spaces, punctuation, etc.).

Задание 2

Create a text file named with the current date in the format year-month-day.

Задание 3

The file contains numbers separated by commas. Get the maximum of these numbers.

Задание 4

Given a text file, get an array of all its lines.