Add hello world demo (#3)

README.md

@@ -10,13 +10,13 @@
 
 <br>
 
-* **[1. Introduction to the Solana Blockchain](chapters/1_intro.md)**
-* **[2. Setup a Developing Environment](chapters/2_dev_env.md)**
-* **[3. Mastering the Anchor Framework](chapters/3_anchor.md)**
-* **[4. Master Solana Frontend](chapters/4_frontend.md)**
-* **[5. In-Depth Solana Programs, SPL, CPI](chapters/5_programs_in_depth.md)**
-* **[6. Transfer Hooks](chapters/6_transfer_hooks.md)**
-* **[7. External Resources to Keep Sharpening Your Axe](chapters/7_sharpening_your_axes.md)**
+* **[1. Introduction to the Solana Blockchain](chapters/01_intro.md)**
+* **[2. Setup a Developing Environment](chapters/02_dev_env.md)**
+* **[3. Mastering the Anchor Framework](chapters/03_anchor.md)**
+* **[4. Master Solana Frontend](chapters/04_frontend.md)**
+* **[5. In-Depth Solana Programs, SPL, CPI](chapters/05_programs_in_depth.md)**
+* **[6. Transfer Hooks](chapters/06_transfer_hooks.md)**
+* **[7. External Resources to Keep Sharpening Your Axe](chapters/07_sharpening_your_axes.md)**
 
 
 
@@ -27,24 +27,24 @@
 
 <br>
 
-#### Introduction
+#### Beginner
 
 <br>
 
-* **[1. Hello World](demos/1_hello_world)**
-* **[2. Functions, Constructors, Math, Errors](demos/2_functions)**
-* **[3. Anchor and the Interface Definition Language](demos/3_anchor)**
-* **[4. Solidity vs. Solana](demos/4_sol_vs_sol)**
-* **[5. Rust, Structs, Custom Derive Macros](demos/5_rust)**
-* **[6. Block Variables, Sysvars](demos/6_blocks)**
-* **[7. Logs, Events, Transactions](demos/7_logs_events_txs)**
-* **[8. Transaction Fees and Compute Units](demos/8_transactions)**
-* **[9. Accounts and Storage](demos/9_accounts_and_storage)**
+* **[1. Hello World](demos/01_hello_world)**
+* **[2. Functions, Constructors, Math, Errors](demos/02_functions)**
+* **[3. Anchor and the Interface Definition Language](demos/03_anchor)**
+* **[4. Solidity vs. Solana](demos/04_sol_vs_sol)**
+* **[5. Rust, Structs, Custom Derive Macros](demos/05_rust)**
+* **[6. Block Variables, Sysvars](demos/06_blocks)**
+* **[7. Logs, Events, Transactions](demos/07_logs_events_txs)**
+* **[8. Transaction Fees and Compute Units](demos/08_transactions)**
+* **[9. Accounts and Storage](demos/09_accounts_and_storage)**
 
 
 <br>
 
-#### Intermediary
+#### Advanced
 
 <br>
 
@@ -58,7 +58,7 @@
 
 <br>
 
-#### Advanced
+#### Expert
 
 <br>
 

demos/01_hello_world/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "hello_world"
+version = "0.1.0"
+
+[lib]
+name = "hello_world"
+crate-type = ["cdylib", "lib"]
+
+[dependencies]
+solana-program = "=1.18.8"

demos/01_hello_world/README.md

@@ -0,0 +1,135 @@
+# 🛹 Demo 1: Hello World 
+
+
+<br>
+
+* In a separate terminal window, start your local cluster:
+
+```shell
+solana-test-validator
+```
+
+<br>
+
+* Initialize a new Rust library via Cargo:
+
+```shell 
+cargo init hello_world --lib
+cd hello_world
+cargo add solana-program
+```
+
+<br>
+
+* This creates a very basic Solana Rust program following this layout:
+
+```shell
+.
+├── Cargo.toml
+└── src
+    └── lib.rs
+```
+
+<br>
+
+* You should modify `Cargo.toml` to the following:
+
+```
+[package]
+name = "hello_world"
+version = "0.1.0"
+
+[lib]
+name = "hello_world"
+crate-type = ["cdylib", "lib"]
+
+[dependencies]
+// add the right version
+solana-program = "=1.1x.x"
+```
+
+
+<br>
+
+* We will write this program inside `src/lib.rs`. 
+
+* At the top, we import the `solana-program` crate and bring needed items into the local namespace:
+
+```rust
+use solana_program::{
+    account_info::AccountInfo,
+    entrypoint,
+    entrypoint::ProgramResult,
+    pubkey::Pubkey,
+    msg,
+  };
+```
+
+<br>
+
+* Every Solana program must define an `entrypoint` that tells the runtime where to start executing the code on-chain. 
+    - The entry point should provide a public function named `process_instruction`:
+
+```rust
+entrypoint!(process_instruction);
+
+pub fn process_instruction(
+   _program_id: &Pubkey,
+   _accounts: &[AccountInfo],
+   _instruction_data: &[u8]
+  ) -> ProgramResult {
+
+   msg!("Only possible on Solana");
+
+   Ok(())
+}
+```
+
+
+<br>
+
+* Note that every on-chain program should return the `Ok` result enum with value `()`. 
+    - This tells the Solana runtime that the program executed successfully.
+
+<br>
+
+
+#### Build and Deploy your Program
+
+<br>
+
+* Let's build this hello world program, by running the following command from the root of the project:
+
+```
+cargo build-sbf
+```
+
+<br>
+
+* This command will create the compiled program's `.so` file inside a folder called `./target/deploy`:
+
+```
+find . -name '*.so'
+```
+
+<br>
+
+* Now, let's deploy it:
+
+
+```
+solana program deploy ./target/deploy/hello_world.so 
+```
+
+<br>
+
+* When this program finishes being deployed, the program's public address (`program id`) is displayed.
+
+* You can check your Solana wallet's balance to see how much it costs to deploy this simple program.
+
+```shell
+solana balance
+```
+
+<br>
+

demos/01_hello_world/src/lib.rs

@@ -0,0 +1,23 @@
+extern crate solana_program;
+
+use solana_program::{
+    account_info::AccountInfo,
+    entrypoint,
+    entrypoint::ProgramResult,
+    pubkey::Pubkey,
+    msg,
+  };
+
+
+entrypoint!(process_instruction);
+
+pub fn process_instruction(
+   _program_id: &Pubkey,
+   _accounts: &[AccountInfo],
+   _instruction_data: &[u8]
+  ) -> ProgramResult {
+
+   msg!("Only possible on Solana");
+
+   Ok(())
+}