Failed to print INFO and WARNING log

[GOGOYAO]

I use glog 0.3.4 and my test code is :

#include <iostream>
#include <chrono>
#include <thread>
#include <string.h>
#include <stdio.h>

#include <glog/logging.h>

int main(int argc, char** argv) {
    google::ParseCommandLineFlags(&argc, &argv, true);
    google::InitGoogleLogging(argv[0]);
    std::cout << FLAGS_minloglevel << std::endl;
    LOG(INFO) << "GLOG";
    LOG(WARNING) << "GLOG";
    LOG(ERROR) << "GLOG";
}

Then I run

g++ -I /usr/local/include/ -L /usr/local/lib/ -lglog -lgflags test.cpp && ./a.out -minloglevel=1
g++ -I /usr/local/include/ -L /usr/local/lib/ -lglog -lgflags test.cpp && ./a.out -minloglevel=2
g++ -I /usr/local/include/ -L /usr/local/lib/ -lglog -lgflags test.cpp && ./a.out -minloglevel=3

But only ERROR log is printted in those three tests.

[GOGOYAO]

I see the --logtostderr or --alsologtostderr can solve this issue