C, SDL2 on Linux

/* rectangle-sdl - Draw a yellow rectangle. */
/* main.cpp /
/* Released into the Public Domain on Mar 17 2018 by Tilman Kranz . */

#include <SDL2/SDL.h>

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

void doWait() {
    SDL_Event event;

    while(1) {
        while(SDL_WaitEvent(&event)){
            switch(event.type){
                case SDL_KEYDOWN:
                    return;
                default:
                    break;
            }
        }

        fprintf(stderr, "ERROR: SDL_WaitEvent(): %s\n", SDL_GetError());
    }
}

int main (int argc, char** argv) {
    int rv;
    SDL_Window* window = NULL;

    window = SDL_CreateWindow("A Yellow Rectangle", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_SHOWN);

    rv = SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN);

    if(rv!=0) {
        fprintf(stderr, "ERROR: SDL_SetWindowFullscreen(): %s\n", SDL_GetError());

        exit(1);
    }

    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);

    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
    SDL_RenderClear(renderer);

    SDL_Rect r = {10, 20, 100, 75};

    SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255);
    SDL_RenderFillRect(renderer, &r);
    SDL_RenderPresent(renderer);

    doWait();

    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}