# C++ Exercise — "Hello, You!"

**Goal:** Write, compile, and run a C++ program that asks for your name. Then automate the build with a Makefile.

**Time:** ~10–15 minutes

---

### Step 1 — Write the program

```bash
cd ~/my-project
nano greet.cpp
```

Type this in:

```cpp
#include <iostream>
#include <string>

int main() {
    std::string name;
    std::cout << "What is your name? ";
    std::getline(std::cin, name);
    std::cout << "Hello, " << name << "!" << std::endl;
    return 0;
}
```

Save: **Ctrl + O**, then **Enter**  
Exit: **Ctrl + X**

### Step 2 — Compile it

```bash
clang++ -Wall greet.cpp -o greet
```

- `-Wall` turns on warnings (catches mistakes)
- `-o greet` names the output file `greet`

If there are no errors, no message is printed — that's good!

### Step 3 — Run it

```bash
./greet
```

Type your name and press **Enter**. It should say hello back.

### Step 4 — Create a Makefile

```bash
nano Makefile
```

Type this:

```make
CXX      = clang++
CXXFLAGS = -Wall -std=c++20
TARGET   = greet

$(TARGET): greet.cpp
	$(CXX) $(CXXFLAGS) greet.cpp -o $(TARGET)

clean:
	rm -f $(TARGET)

.PHONY: clean
```

**Important:** The indented lines must use a **Tab** character, not spaces.

Save and exit (**Ctrl + O**, **Enter**, **Ctrl + X**).

### Step 5 — Build with make

```bash
make clean
make
```

`make clean` deletes the old `greet` binary. `make` rebuilds it.

### Step 6 — Run again (via make build)

```bash
./greet
```

---

**Commands you used:** `nano`, `clang++`, `./` (run), `make`, `make clean`

**What you learned:**
- Writing a basic C++ program with input and output
- Compiling with `clang++` and useful flags
- Creating a `Makefile` to automate the build
- Using `make` and `make clean`