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

cd ~/my-project
nano greet.cpp

Type this in:

#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

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

./greet

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

Step 4 — Create a Makefile

nano Makefile

Type this:

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

make clean
make

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

Step 6 — Run again (via make build)

./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

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