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Shoichi Okaniwa
Shoichi Okaniwa

Posted on • Originally published at qiita.com

gccのDocker公式イメージ使ってC++でHelloWorldしてみた

#c #gcc #docker

Introduction to Handling C++ Code

In our ongoing web service project, we need to work with C++ source code. Our goal is to ensure that this code compiles and runs in a Linux environment using GCC inside a Docker container. We are not using make or focusing on minimizing the environment size for now.

You can find the sample code created for this purpose here.

Searching for a Docker Image

Searching for GCC on Docker Hub revealed an official image available here.

We'll use this image (although there might be a lighter one available).

Creating the C++ Source Code

Let's create a simple Hello World! program in C++.

#include <iostream>

int main()
{
    std::cout << "Hello world!" << std::endl;
}
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Creating a Script for Compiling and Executing

Here's a script to compile the C++ file. Place it in the same directory as your .cpp file.

#!/bin/bash

# Compile
g++ hello.cpp -o hello

# Execute
./hello
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Creating docker-compose.yml

After pulling the official Docker image, we'll use it to execute build.sh.

version: '3'
services:
  gcc-cpp-sample:
    image: 'gcc:9.2'
    volumes:
      - ./cpp:/src/cpp
    working_dir: /src/cpp
    command: ./build.sh
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Ensure the cpp folder is at the same level as docker-compose.yml, and place hello.cpp and build.sh inside it.

Execution!

By executing the command:

docker-compose up
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the message Hello World! was successfully displayed!

Sample Code

You can find the sample code here. In addition to what's covered in this article, it also includes compiling and executing C language programs.

Conclusion

Returning to GCC after about 10 years was a great mental exercise.

This article was created with reference to the following resources. Thank you for the clear and informative articles.

Additionally, if you're concerned about the size of the official Docker image, you may want to consider Alpine Linux for a lighter environment. Here's a comprehensive guide:

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