创建线程求救 [复制链接]

小弟编了一个简单的创建线程程序想验证一下，确总有这种错误

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>

void task(int *counter)
{
fprintf(stderr,"task runing\n");
}

int arg;
static pthread_t tid;

int main()
{
int ret=pthread_create(&tid,NULL,task,(void*)&arg);
if(ret)
{
  fprintf(stderr,"success\n");
}
}


[root@localhost testdir]# gcc main.c -o main
main.c: In function `main':
main.c:15: warning: passing arg 3 of `pthread_create' from incompatible pointer
type
/tmp/cc67xs1l.o(.text+0x40): In function `main':
: undefined reference to `pthread_create'
collect2: ld returned 1 exit status


那位兄弟能给小弟解释一下。

加 -lpthread

///////////////////file.cpp///////////////////
#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>

void *task(void *counter)
{
   fprintf(stderr,"task runing\n");
   return NULL;
}

int arg;
static pthread_t tid;

int main()
{
   int ret=pthread_create(&tid,NULL,task,(void*)&arg);
   if(ret)
   {
       fprintf(stderr,"success\n");
   }
   return 0;
}

#g++ -o file file.cpp -pthread