26.2. Orphans and Zombies

The lifetimes of parent and child processes are usually not the same—either the parent outlives the child or vice versa. This raises two questions:

• Who becomes the parent of an orphaned child? The orphaned child is adopted by init, the ancestor of all processes, whose process ID is 1. In other words, after a child’s parent terminates, a call to getppid() will return the value 1. This can be used as a way of determining if a child’s true parent is still alive (this assumes a child that was created by a process other than init).