Help with fork()

[MrDiaz]

Hi everyone,

I'm trying to accomplish the following; I need to create 2 subprocesses and each subprocess should create a process of their own.

Should look like this:

I'm child xxxx parent xxxx
I'm the subchild xxxx parent xxxx
I'm the second child xxxx parent xxxx
I'm the second subchild xxxx parent xxxx

So far I have this:


#include <stdio.h>
#include <unistd.h>

int main(void) {
int pid;
pid = fork();
if (pid == 0) { // Child process
printf("I'm the child %d parent %d\n", getpid(), getppid());
pid = fork();
if (pid == 0) { // Subchild process
printf("I'm the subchild %d parent %d\n", getpid(), getppid());
}
}
wait();
return 0;
}

So far I've only been able to create one child from a process, I need to create two childs and two subchilds. The logic is below, hope it makes sense

PARENT PROCESS
CHILD PROCESS CHILD PROCESS
SUBCHILD OF 1ST CHILD SUBCHILD OF SECOND CHILD

[gmargo]

So far I've only been able to create one child from a process, I need to create two childs and two subchilds.

I don't see what your question is. You created one child and one grandchild. Now do it again.

[johnl]

Untested. The break is probably important (see if you can figure out why :) )


#include <stdio.h>
#include <unistd.h>

int main(void) {
int pid, i;
pid = fork();

if (pid == 0) { // Child process
printf("I'm the child %d parent %d\n", getpid(), getppid());
for(i = 0; i < 2; ++i) {
pid = fork();
if (pid == 0) { // Subchild process
printf("I'm the subchild %d parent %d\n", getpid(), getppid());
break;
}
}
}
wait();
return 0;
}

[MrDiaz]

That's an interesting way of doing it. Anyway I did it like this



#include <stdio.h>

int main(void) {

int pID;

pID = fork();
if (pID == 0) { // First Child Process
printf("I am the child %d parent %d\n", getpid(), getppid());

pID = fork();
if (pID == 0)
printf("I am the subchild %d parent %d\n", getpid(), getppid());
}
else {
pID = fork();
if (pID == 0) { // Second Child Process
printf("I am the second child %d parent %d\n", getpid(), getppid());
pID = fork();
if(pID == 0)
printf("I am the second subchild %d parent %d\n", getpid(), getppid());
}
}
return 0;
}