run a compiled executable called ./main

Projects/01_HelloWorld/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, World!");
+}

README.org

@@ -4,7 +4,10 @@
 #+startup: indent
 
 #+link: ch01 https://rust-book.cs.brown.edu/ch01-00-getting-started.html
-* Chapter 01: Installation
+
+* Getting Started
+
+** Chapter 01: Installation
 Recommendation is to use ~rustup~ using the command:
 #+name: install rustup
 #+begin_src shell
@@ -19,7 +22,7 @@ To confirm it's installed:
 
 #+RESULTS: confirm rustup installed
 : rustup 1.26.0 (5af9b9484 2023-04-05)
-** Update
+*** Update
 To update ~rustup~ and please do regularly
 #+name: update rustup
 #+begin_src shell :results output
@@ -30,10 +33,44 @@ To update ~rustup~ and please do regularly
 : 
 :   stable-x86_64-unknown-linux-gnu unchanged - rustc 1.76.0 (07dca489a 2024-02-04)
 : 
-** Documentation
+*** Documentation
 ~rustup~ comes with documentation, just type
 #+begin_src shell
   rustup doc
 #+end_src
 
 and the browser will open a page with links toward lots of docs.
+
+** Chapter 02: Hello, World!
+Basically done in 3 steps:
+- Edit the rs file
+- Compile using ~rustc~
+- Call the executable
+
+
+Work folder is =Projects/01_HelloWorld=, where we create the file =main.rs=
+#+name: hello_world main.rs
+#+begin_src rust
+  fn main() {
+      println!("Hello, World!");
+  }
+#+end_src
+
+To execute this program:
+#+name: 0102 call main
+#+begin_src shell :results output
+  cd Projects/01_HelloWorld/
+  rustc main.rs
+  ./main
+#+end_src
+
+#+RESULTS: 0102 call main
+: Hello, World!
+
+The program wordes, I'm now done.
+
+*** Note
+All rust program starts by calling the function ~main~.
+Functions with ~!~ appended to their name, like ~println!~, are macros.
+
+