如何让你的程序支持管道输入

#include<iostream>
using namespace std;

int main(int argc, char \*argv[])
{
    string s;

    while (cin >> s)
        cout << "hello " << s << endl;

    return 0;
}

[root@CentOS ~]# ls redis-3.0.7 | ./a.out 
hello 00-RELEASENOTES
hello BUGS
hello CONTRIBUTING
hello COPYING
hello deps
hello INSTALL
hello Makefile
hello MANIFESTO
hello README
hello redis.conf
hello runtest
hello runtest-cluster
hello runtest-sentinel
hello sentinel.conf
hello src
hello tests
hello utils