Background

Let us do a quick Hello World Program in Rust.

Steps

1. Create Project
2. Code
3. Build Project
4. Run Application

Tasks

Create Project

Command

Syntax

cargo new <applicationName> --<applicationType>

Sample

cargo new helloWorld --bin

Output

Output – Image

Output – Text

>cargo new helloWorld --bin
     Created binary (application) `helloWorld` package

>

Code

Outline

1. Files
   • Package Handling ( manifest file )
     • cargo.toml
       • Add required modules
   • Source Code
     • src\main.rs
       • Add a bit more code to the main file ( main.rs )

 

Tasks

Files

Package Handling ( Manifest File )

cargo.toml

[package]
name = "helloWorld"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]

# Added by dadeniji on 2022-09-14 09:02 AM
# This line identifies the whoami crate as one of the dependencies
# https://crates.io/crates/whoami/0.9.0
whoami = "0.9.0"

Source Code

src\main.rs

fn main() {
    
    //println!("Hello, world!");
    
    say_hello();
    
}

/*
    WhoAmI
    https://crates.io/crates/whoami/0.9.0
*/
fn say_hello(){

    /*
        Declare Variables
    */
    let user_realname:String;
    let user_hostname:String;
    let user_username:String;

    /*
        Set Variable Values
    */
    user_realname = whoami::realname();
    
    user_hostname = whoami::hostname();

    user_username = whoami::username();
        
    // Print text to the console
    println!("Hello {0}", user_realname);       
    
    println!(
                  "Your username on this system ({0}) is {1}"
                , user_hostname
                , user_username
            );    
 
    
}

Build Project

Command

Syntax

cargo build

Sample

>cargo build
warning: crate `helloWorld` should have a snake case name
  |
  = note: `#[warn(non_snake_case)]` on by default
  = help: convert the identifier to snake case: `hello_world`

warning: `helloWorld` (bin "helloWorld") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.02s

>

Output

Output – Image

Output – Text

>cargo build
warning: crate `helloWorld` should have a snake case name
  |
  = note: `#[warn(non_snake_case)]` on by default
  = help: convert the identifier to snake case: `hello_world`

warning: `helloWorld` (bin "helloWorld") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.02s

>

Run Project

Command

Syntax

cargo run

Sample

cargo run

Output

Output – Image

Output – Text

>cargo run
warning: crate `helloWorld` should have a snake case name
  |
  = note: `#[warn(non_snake_case)]` on by default
  = help: convert the identifier to snake case: `hello_world`

warning: `helloWorld` (bin "helloWorld") generated 1 warning
    Finished dev [unoptimized + debuginfo] target(s) in 0.02s
     Running `target\debug\helloWorld.exe`
Hello Adeniji, Daniel
Your username on this system (devmachine01) is dadeniji

>

Summary

Like Dixie Chicks took the long way home on this one.

Points Made.

1. Project
   • cargo new
     • Solid Folder Structure
     • Stub Files Created
       • cargo.toml
       • src\main.rs
2. Convention
   • Quite Heady about names
     • Project Names
     • File Names
     • Variable Names