[learning notes] process creation

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

int pipeline_child()
{
    
	printf("child PPID:%d,PID:%d\n", getppid(), getpid());
	while(1);
	return 0;
}

int pipeline_father()
{
    
	printf("father PPID:%d,PID:%d\n", getppid(), getpid());
	while(1);
	return 0;
}

int main()
{
    
	pid_t pid = fork();

	if (pid == -1) {
    
		printf("failed process!\n");
		return -1;
	}
	// Subprocesses 
	if(pid == 0) {
    
		printf("child process!\n");
		printf("child PPID:%d,PID:%d\n", getppid(), getpid());
		pipeline_child();
	} else {
    
		// The parent process 
		sleep(1);
		printf("father process!\n");
		printf("father PPID:%d,PID:%d\n", getppid(), getpid());
		pipeline_father();

	}

	return 0;
}