So I need to write a c++ code that takes two user input commands.

command1 and command2. The program should then pipe, fork and then execute the commands. The user input should be treated as a unix shell command line.

for example

command1: ls

command2: wc

1 4 16

I have code that takes the first two, however, when I execute it after it takes the commands it loops the reponse back endlessly. I can not figure out what line in the code is causing it to loop forever.

Here is my code :

#include

#include

#include

#include

#include

#include

#include

#include

#include

using namespace std;

int main()

{

//Variables

string command1, command2;

bool quit = false;

while(quit!= true)

{

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

cin >> command1;

if(command1 == "quit")

{

quit = true;

break;

}

cout << "Enter your second command (including arguments): ";

cin >> command2;

if(command2 == "quit")

{

quit = true;

break;

}

//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);

}

}

}

return 0;

}