Program goes into infinite loop. Please help

[nikkoNIU]

Im writing a program that prompts the user for 2 commands. Each input string should be a UNIX command, with arguments allowed. For example, input 1 could be "ls -l" and input 2 could be "wc -l". The program will then create a pipe, and two child processes. The first child process will run the command specified in the first input. It will output to the pipe instead of standard output. The second child process will run the command specified in the second input. It will take its input from the pipe rather than standard input.
The parent process will wait on its two children to complete, then the whole thing will repeat. Execution will stop when "quit" is entered as the first command.

It seems like it goes into an infinite loop. I think it has something to do with both of the waits in the last parent process, I have been messing with them for a while and reading but nothing seems to work. Can someone point me in the right direction on where my mistake is? thanks in advance


#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <cstring>
#include <stdlib.h>
#include <iostream>
using namespace std;

int main()
{
//Variables
string command1, command2;
char quit[]="quit";

cout << "Enter your first command (including arguments) or quit to exit: ";
cin >> command1;

while(command1!="quit")
{
cout << "Enter your second command (including arguments): ";
cin >> command2;

//Create pipe
int pipefd[2];
int rs=pipe(pipefd);
//error check pipe
if(rs==-1)
{
perror("pipe");
exit(EXIT_FAILURE);
}


//fork into two processes
rs=fork();
//error check fork
if(rs==-1)
{
perror("pipe");
exit(EXIT_FAILURE);
}


//child process
if(rs==0)
{
//close read end of pipe, keep write end open
close(pipefd[0]);
//close standard output
close(1);
//duplicate write end of pipe into standard output
dup(pipefd[1]);
//close write end of pipe
close(pipefd[1]);
//run the first command
rs=execlp(command1.c_str(), command1.c_str(), (char*)NULL);
//error check execlp
if(rs==-1)
{
perror("execlp");
exit(EXIT_FAILURE);
}
}


//parent process
else
{
//close write end of pipe, keep read open
close(pipefd[1]);
//close standard input
close(0);
//duplicate read end of pipe into standard input
dup(pipefd[0]);
//close read end
close(pipefd[0]);
//fork into two processes
rs=fork();
//error check the fork
if(rs==1)
{
perror("pipe");
exit(EXIT_FAILURE);
}


//child process 2
if(rs==0)
{
//run second command
rs=execlp(command2.c_str(), command2.c_str(), (char*)NULL);
//error check execlp
if(rs==-1)
{
perror("execlp");
exit(EXIT_FAILURE);
}
}


//parent process
else
{
wait(NULL);
wait(NULL);
}

}
cout << "Enter your first command (including arguments) or quit to exit: ";
cin >> command1;
}
return 0;
}