Besides `Args` given by the user in `std::env`, there are also `Vars` which are the system variables. Those are the basic settings for the program that the user didn't type in. You can use `std::env::vars()` to see them all as a `(String, String)`. There are very many. For example:
```rust
fn main() {
for item in std::env::vars() {
println!("{:?}", item);
}
}
```
Just doing this shows you all the information about your user session. It will show information like this:
So if you need this information, `Vars` is what you want.
## Using files
Now that we are using Rust on the computer, we can start working with files. You will notice that now we will start to see more and more `Result`s in our code. That is because once you start working with files and similar things, many things can go wrong. A file might not be there, or maybe the computer can't read it.
Dhghomon
4 years ago
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GitHub