编译环境 Ubuntu18.04 G++

#include <pthread.h>
#include <stdlib.h>
#include <iostream>
#include <stdio.h>
#include <unistd.h>
using namespace std;

void * funct(void * arg)
{
    static int i=0;
    
  
    printf("hello %d\n",i);
    i++;
    sleep(4);
    printf("wake UP%d\n",i);
    i++;

    
}
int main()
{
    pthread_t  threadFunctID;

    int returnvalue=pthread_create(&threadFunctID,NULL,&funct,NULL);
    if (returnvalue)
    {
        //成功为0 失败有值
        printf("error");
    }
    else
    {
        
        printf("success\n");
        cout<<"thread1 ID is "<<threadFunctID<<endl;
    }
      cout<<pthread_self<<"!!!!!"<<endl;
    int returnvalue2=pthread_create(&threadFunctID,NULL,&funct,NULL);
    if (returnvalue2)
    {
        //成功为0 失败有值
        printf("error");
    }
    else
    {
        
        printf("success\n");
        cout<<"thread2  ID is"<<threadFunctID<<endl;
    }
      cout<<pthread_self<<"!!!!!"<<endl;
    //way2 use detach
    int err=pthread_detach(threadFunctID);
    if(err)
    {
        cout<<"error"<<endl;
    }
    sleep(8); //the main function wait for thread to exit 
    // you can test it for change the 
//way1 use join
    // cout<< "wait for thread to exit\n";

    // returnvalue=pthread_join(threadFunctID,NULL);
    // if(returnvalue)
    // {
    //     printf("error");

    // }
    cout<<"Exit main\n";
    return 0;
}