How to get environment variables in C

main.c

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char* argv[], char* envp[]) {
    char* env_variable = getenv("API_KEY");
    if (env_variable == NULL) {
        printf("No environment variable was found\n");
        return 1;
    }
    printf("The value of our environment variable is %s\n\n", env_variable);
    return 0;
}

Quickstart guide for C pointers

Pointers, double pointers, pointer arithmetics, dereferencing, everything in a short and compact guide that you can reference anytime!