Question

I have found examples of how to fork multiple children by having something like this:

if ( fork() = 0 ) {
    //In child
} else {
    if ( fork() = 0 ) {
       //in second child

But if I don’t know how many children I am going to need, how might I do this?

For instance, if I have a linked list of commands, and I want to fork and exec for each of them… So I guess I need to know which child it is as well…

Answer 1

Taking you at your word that you need to do this for a linked list:

linked_list_of_commands_t *node = root;
while (node != NULL) {
   int pid = fork();
   if (pid == -1) {
       break; // handle error
   } else if (pid == 0) {
       // child
       execv(node->command, node->argv);
       exit(1); // execv should not return, but just in case the execv call fails
   } else {
       node = node->next;
   }
}

This will launch a separate process for every item in the list.