Thread: fork() command

Hi,
I was wondering how fork() executes, that is does the child finish first then lets the parent finish or do they execute at the same time working on the same code?

Also my other question is: if i have 2 processes parent and its child and now I want to create a 3rd process running of the child of the parent. Now the 3rd process will become the child of the child process. So the 2nd process will now also be a parent process as well as a child process. How would I use if thens to do this?

Thank you

thank you very much

Question:
do I have to include fork() again to create a grandchild? such as:


if ( fork() == 0 ) {
fork()
if ( fork() == 0 ) {
// grandchild
}
// child
}
// parent

oh man..sorry, im a fool.
i usually assigne pid = fork()

i did not see at first the fork()==0.

heh

what if the parent process..may it be the parent of the grandchild or just the child of the original parent, need to finish something first such as read or write some data to a file then the child has to do some work on that file. How can I make sure the the oder is preserved, or should I use pointers some how?

is there any other way to do this other then pipe? I just want to make sure that parent does something things first before going onto the child without shared memory.

Originally Posted by saphiroth

is there any other way to do this other then pipe? I just want to make sure that parent does something things first before going onto the child without shared memory.

This is called a race condition and is solved by the parent telling the child when it is done. A pipe is the mechanism the two process can use to communicate.