I/O Loop using Fork() and Pipe()

[Yomaster]

Hi, everyone, I'm working on a college assignment and I'm having a bit of difficulty getting it to work properly. The assignment calls for us to write a C++ program using Linux system calls which creates a pipe and forks a child process. As a whole, this program is supposed to loop accepting input from the user, write it to the pipe, and then print the command it received back into the console, unless it receives a "T" command, which terminates the program.

The parent process is responsible for prompting, accepting input, and writing to the pipe. The child process is responsible for reading from the pipe, and displaying this result in the console.

The problem I have, is that it continues to loop asking for input commands, but only prints the first command it receives. I've sat here for hours trying to figure this out. Read the relevant man pages. Watched YouTube videos. Nothing is helping me. I'm obviously pretty new to programming and I assume I'm just not seeing it. What am I doing wrong here?

Thanks in advance for any help.

       #include <sys/types.h>
       #include <sys/wait.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <unistd.h>
       #include <string.h>  
       #include <iostream>

       using namespace std;

       int
       main()
       {
           int pipefd[2];
           pid_t cpid;
           char buf;
           
           if (pipe(pipefd) == -1) {
               perror("pipe");
               exit(EXIT_FAILURE);
           }
           
           cpid = fork();
           if (cpid == -1) {
               perror("fork");
               exit(EXIT_FAILURE);
           }  
           
              
           if (cpid == 0) {    //Child process
               read(pipefd[0], &buf, 1);
               cout << buf << " command received.\n";
           }
           else {  //Parent process
               do{
               cout << "Enter a command (q, u, p, t): "; 
               cin >> buf; 
               write(pipefd[1], &buf, 1);
               wait(NULL);
               }while(buf != 't');
               if(buf == 't'){
                   cout << "Exiting program...";
                   close(pipefd[1]);
                   close(pipefd[0]);
                   exit(EXIT_SUCCESS);
               }
           }
           
       }

[Yomaster]

Solved it!

       #include <sys/types.h>
       #include <sys/wait.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <unistd.h>
       #include <string.h>  
       #include <iostream>

       using namespace std;

       int
       main()
       {
           int pipefd[2];
           pid_t cpid;
           char buf;
           
           if (pipe(pipefd) == -1) {
               perror("pipe");
               exit(EXIT_FAILURE);
           }
           
           cpid = fork();
           if (cpid == -1) {
               perror("fork");
               exit(EXIT_FAILURE);
           }  
              
           if (cpid == 0) {    //Child process
               do{    
               read(pipefd[0], &buf, 1);
               cout << buf << " command received.\n";
               }while(buf != 't');
                   if(buf =='t'){
                       close(pipefd[0]);
                       close(pipefd[1]);
                       _exit(EXIT_SUCCESS);
                   }
           }
           else {  //Parent process
               do{
               cout << "Enter a command (q, u, p, t): ";   
               cin >> buf; 
               write(pipefd[1], &buf, 1);
               }while(buf != 't');
               if(buf == 't'){
                   cout << "\nExiting program...";
                   close(pipefd[1]);
                   close(pipefd[0]);
                   exit(EXIT_SUCCESS);
               }
           }  
       }