C++ thread函数使用

#include <thread>
#include <iostream>
using namespace std;

int shared_value = 0;
void change_value (int n){
	for (int i = 0; i < n; i++){
		shared_value++;
	}
}

int main (){
	thread t[100];
	for (int i = 0; i < 100; i++){
		t[i] = thread (change_value, 1000);
	}
	for (int i = 0; i < 100; i++){
		t[i].join();
	}
	cout << shared_value << endl;
	return 0;
}

　　

编译命令 g++ -std=c++11 - main.cpp -o main -pthread

小爬虫

#include <bits/stdc++.h>
using namespace std;

string url[4] = {
	"http://www.baidu.com",
	"http://www.ismdeep.com",
	"http://www.chinaedu.edu.cn/",
	"http://www.neea.edu.cn/"
};

void get_html_content (string _url){
	char bash[100] ={"wget \""}, a[100], b[]="\"";
	for(int i = 0; _url[i]; i++){
		a[i] = _url[i];
	}
	strcat(bash, a);
	strcat(bash, b);
	system(bash);
}

int main (){
    thread t[100];
    for (int i = 0; i < 4; i++){
        t[i] = thread(get_html_content,url[i]);
		t[i].join();
    }
    return 0;
}