Environment Variables

First, we need to add dotenv-c to our project, and then create a .env file in the root directory of our project. Project structure should something be like this:

your-project/
├── CMakeLists.txt
├── .env
└── src/
    └── main.c

We define a PORT in .env:

.env

PORT=3000

Let’s parse it in main.c:

src/main.c

#include <stdio.h>
#include "server.h"
#include "dotenv.h"

int main()
{
    env_load("..", false);              // Load ".env" file
    const char *port = getenv("PORT");  // Get the "PORT"
    printf("PORT: %s\n", port);         // Print the "PORT"

    ecewo(3000);                        // Start the server
    return 0;                           // Exit
}

We’ll see the PORT in the console when building the program. However, getenv returns a const char * everytime, and if we need to retrieve a non-character type variable, we must convert it first.

For example, ecewo() takes an unsigned short type variable. So, if we want to use the PORT from the .env file, we can do it like this:

src/main.c

#include "server.h"
#include "dotenv.h"

int main()
{
    env_load("..", false);

    const char *port = getenv("PORT");
    const unsigned short PORT = (unsigned short)atoi(port);

    ecewo(PORT);
    return 0;
}