[系统运维]多线程linux报错undefined reference to `pthread_create‘

练习多线程时碰到的一个编译报错问题

先上一段多线程的代码,文件名A12_4.cpp

vector<string> ptr;
void *thread(void *vargp) {
    long myid = (long)vargp;
    static int cnt = 0;
    cout << '[' << myid << "]: " << ptr[myid] << " (cnt = " << ++cnt << ")" << endl;
    return nullptr;
}
int main(int argc, char *argv[]) {
   long i;
   pthread_t tid;
   vector<string> msgs = {
      "hello from foo",
      "hello from bar"
   };
   ptr = msgs;
   for (i = 0; i < 2; ++i) {
      pthread_create(&tid, nullptr, thread, (void*)i);
   }
   pthread_exit(nullptr);
}

在命令行输入g++ A12_4.cpp -o ss时报错undefined reference to `pthread_create’

查阅资料后得到答案:
For Linux the correct command is:

gcc -pthread -o term term.c

In general, libraries should follow sources and objects on command line, and -lpthread is not an “option”, it’s a library specification. On a system with only libpthread.a installed,

c++中只需要把gcc改称g++即可

g++ -pthread -o term A12_4.cpp

参考网页:Undefined reference to pthread_create in Linux