preap(1) (man pages section 1: User Commands)

man pages section 1: User Commands

preap(1)

NAME

preap– force a defunct process to be reaped by its parent

SYNOPSIS

preap

-F

pid

DESCRIPTION

A defunct (or zombie) process is one whose exit status has yet to be reaped by its parent. The exit status is reaped via the wait(2), waitid(2), or waitpid(2) system call. In the normal course of system operation, zombies may occur, but are typically short-lived. This may happen if a parent exits without having reaped the exit status of some or all of its children. In that case, those children are reparented to PID 1. See init(1M), which periodically reaps such processes.

An irresponsible parent process may not exit for a very long time and thus leave zombies on the system. Since the operating system destroys nearly all components of a process before it becomes defunct, such defunct processes do not normally impact system operation. However, they do consume a small amount of system memory.

preap forces the parent of the process specified by pid to waitid(2) for pid, if pid represents a defunct process.

preap will attempt to prevent the administrator from unwisely reaping a child process which might soon be reaped by the parent, if:

The process is a child of init(1M).
The parent process is stopped and might wait on the child when it is again allowed to run.
The process has been defunct for less than one minute.

OPTIONS

The following option is supported:

-F: Forces the parent to reap the child, overriding safety checks.

OPERANDS

The following operand is supported:

pid: Process ID list.

EXIT STATUS

The following exit values are returned by preap, which prints the exit status of each target process reaped:

0: Successfully operation.
non-zero: Failure, such as no such process, permission denied, or invalid option.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Availability	SUNWesu (32–bit)
	SUNWesxu (64–bit)

WARNINGS

preap should be applied sparingly and only in situations in which the administrator or developer has confirmed that defunct processes will not be reaped by the parent process. Otherwise, applying preap may damage the parent process in unpredictable ways.

SunOS 5.9 Last Revised 26 Mar 2001