unix環境高編中exec函數執行個體

#include <iostream>
using namespace std;

int main(int argc,char *argv[])
{
cout<<argv[1]<<endl;
return 0;

}

g++ -o ss ss.cpp

extern "C"{
#include <unistd.h>
}
#include <iostream>
using namespace std;

int main()
{
pid_t pid;
if((pid=fork())<0)
{
cout<<"error to creat child progress"<<endl;
}
else if(pid==0){
cout<< "i am child . my pid is"<<getpid()<<endl;
execl("./ss","./ss","hello",(char *)0);
}
else{
cout<<"i am parent, my pid is" <<getpid()<<endl;
}
return 0;

}

g++ -o exec exec.cpp

./exec

./exec
i am parent, my pid is6321
i am child . my pid is6322
 hello