Question

Write a C program that does the following. Parent sends “Hello, there”, child responds with “Hi, I’m child”. Then the parent sends “Are you available now?” and the child responds with “Yes, I’m”. Make appropriate usage of pipes.

Answer 1

#include <stdio.h>

#include <unistd.h>

#include <sys types.h="">

#include <stdlib.h>

#include <memory.h>

int main() {

//for parent to child

int parentToChild[2];

//for child to parent

int childToParent[2];

//string data

char message1[] = "Hello, there";

char message2[] = "Hi, I’m child";

char message3[] = "Are you available now?";

char message4[] = "Yes, I’m";

char readBuffer[120];

pipe(parentToChild);

pipe(childToParent);

int processId , bytes;

if((processId = fork())== -1){

printf("error while creating a child process");

}

if(processId !=0 ){

//parent process here

//send message from parent to child

close(parentToChild[0]);

write(parentToChild[1] , message1 , strlen(message1)+1);

//recieve message from child

close(childToParent[1]);

bytes = read(childToParent[0] , readBuffer , sizeof(readBuffer));

printf("%s", readBuffer);

// exit(1);

}

if(processId == 0){

//child process here

//send message from child to parent

close(childToParent[0]);

write(childToParent[1] , message2 , strlen(message2)+1);

//recive message from parent

close(parentToChild[1]);

bytes = read(parentToChild[0] , readBuffer , sizeof(readBuffer));

printf("%s",readBuffer);

// exit(1);

}

if(processId !=0 ){

//parent process here

//send message from parent to child

close(parentToChild[0]);

write(parentToChild[1] , message3 , strlen(message3)+1);

//recieve message from child

close(childToParent[1]);

bytes = read(childToParent[0] , readBuffer , sizeof(readBuffer));

printf("%s", readBuffer);

// exit(1);

}

if(processId == 0){

//child process here

//send message from child to parent

close(childToParent[0]);

write(childToParent[1] , message4 , strlen(message4)+1);

//recive message from parent

close(parentToChild[1]);

bytes = read(parentToChild[0] , readBuffer , sizeof(readBuffer));

printf("%s",readBuffer);

// exit(1);

}

return 0;

}