Fork multi process with only on parent in C - c

Question

I have a project in which I have to fork A B C and D process from one parent which is the original program/main() function. I used pipes to communicate between the processes, and I went through a lot of coding, but I wasn't able to send the right messages between the processes. However, I decide to go back to understand the basic concepts of fork() so I wrote the following code.
------Edited: My question is that can I use this template to send messages via pipes from all 4 processes and read those messages from parent? If so in which parent section I have to write the reading code?
`
if (fork()) { //parent log
printf("Inside parent\n");
if (fork()) { //parent log
printf("Inside parent\n");
if (fork()) { //parent log
printf("Inside parent\n");
if (fork()) { //parent log
printf("Inside parent\n");
}else { //child process D
printf("Inside process D\n");
_exit(1);
}
}else { //child process C
printf("Inside process C\n");
_exit(1);
}
}else { //child process B
printf("Inside process B\n");
_exit(1);
}
}else { //child process A
printf("Inside process A\n");
_exit(1);
}
My goal is to send messages from A to B and from B to C and from B to D, Also send messages from any process (A B C and D) to the parent.
Is this code template correct? Or there is something wrong with its structure?
Thanks a lot.

Answer 1

While your code does create 4 child processes it can be a lot simpler:
int main()
{
int i;
for(i = 0; i < 4; i++) {
printf("getpid = 0x%X\n", getpid());
if(fork()) {
printf("Inside parent\n");
}
else {
printf("Inside process %c\n", 'A'+i);
exit(1);
}
}
}
The key idea is that you can differentiate between each child by the value of i. You can even also use i in a switch statement:
int main()
{
int i;
for(i = 0; i < 4; i++) {
printf("getpid = 0x%X\n", getpid());
if(fork()) {
printf("Inside parent\n");
}
else {
switch(i) {
case 0:
printf("In process A\n");
break;
case 1:
printf("In process B\n");
break;
case 2:
printf("In process C\n");
break;
case 3:
printf("In process D\n");
break;
}
exit(1);
}
}
}