list_egl_options.py

import os
import subprocess

if not os.path.isfile("./EGL_options.o"):
    subprocess.call(["bash", "./build.sh"])

print("----------Default-------------")
p = subprocess.Popen(["./EGL_options.o"], stderr=subprocess.PIPE)
p.wait()
out, err = p.communicate()
print(err)

N = int(err.decode("utf-8").split(" of ")[1].split(".")[0])

print("number of EGL devices: {}".format(N))

for i in range(N):
    print(f"----------Option #{i + 1} (id={i})-------------")
    my_env = os.environ.copy()
    my_env["EGL_VISIBLE_DEVICE"] = "{}".format(i)
    p = subprocess.Popen(["./EGL_options.o"], env=my_env)
    p.wait()
    print()