有2个C生成的文件，需要在开机的时候启动。
按如下方式添加，只能启动第一个
# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.
./etc/nnn1
./etc/nnn2
exit 0
然后修改成如下，也是只能启动前面一个
# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.
cd /etc
./nnn1
cd /etc
./nnn2
exit 0
多次对比测试，发现，这两个程序都是涉及到通信，不返还的，就是不终止程序，一旦启动就一直在运行，相当于不能退出了，所以后面的语句就无法执行了
于是采用了如下方式：
int main(void)
{
int i;
if ( fork() == 0 )
{
/* 子进程程序 */
system("cd /etc");
system("./nnn1");
}
else
{
system("cd /etc");
system("./nnn2");
}
}
相当于多线程运行，然后生成了一个运行文件，nnn3,在rc.loacl中添加如下：
# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.
chmod 777 /etc/nnn3
cd /etc
./nnn3
exit 0
开机可以同时2个程序都运行了
