zombie process

operating system (Or "defunct process") A Unix process

that has terminated (either because it has been killed by a

signal or because it has called exit()) and whose parentprocess has not yet received notification of its termination

by executing (some form of) the wait() system call.

A zombie process exists solely as a process table entry and

consumes no other resources. This entry is retained to hold

the child's exit status until the parent process wants to

retrieve it. The parent can also be notified asynchronously

via a signal of the child's termination.

Zombie processes can be seen in "ps" listings occasionally

(with a status "Z" in some versions).

Compare orphan process.

(1997-10-08)