04-26-2008
So in a nutshell only the parent can wait for the children.
Is there a reason for this ?
Imagine you have a process which want to monitor the other process, the unique way is to be the parent of all them, just like init.
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
Hi,
is-it normal to have 86% of CPU for wait commande :
ps aux| head -20
UTIL PID %CPU %MEM SZ RSS TTY STAT STIME TIME COMMAND
root 516 86,6 0,0 12 12 - A 02 nov 2088:03 wait
oralfa01 54422 4,6 1,0 68044 39868 - A 09:20:06 2:27 oracleALFA01
If... (3 Replies)
Discussion started by: big123456
3 Replies
2. UNIX for Dummies Questions & Answers
When running top, I notice a bit more I/O wait time than usual. Is there a tool or piece of software out there that can me help evaluate the performance of these operations on my machine? Thanks! (5 Replies)
Discussion started by: unavb
5 Replies
3. Shell Programming and Scripting
:cool:
I need to execute a shell script to do the following:
cat a file
run two back ground processes using the first two values from the file
wait till those background processes finish
run two more background processes using the next two values from the file
wait till those background... (1 Reply)
Discussion started by: halo98
1 Replies
4. Shell Programming and Scripting
In one of the shell script (Where abinitio graph is called), the last line is wait ${!}. What does this wait ${!} mean ??? (2 Replies)
Discussion started by: risshanth
2 Replies
5. Shell Programming and Scripting
Did not use 'wait' yet.
How I understand by now the wait works only for child processes, started background.
Is there any other way to watch completion of any, not related process (at least, a process, owned by the same user?)
I need to start a background process, witch will be waiting... (2 Replies)
Discussion started by: alex_5161
2 Replies
6. UNIX for Advanced & Expert Users
can any one please give me clear idea of wait process in UNIX system.
I am using AIX 5.3 and see loots of wait process. I have very basic concept of wait process. If CPU has nothing to do then a wait process is generated per CPU. But i want know the detail how is it forked.
Is wait a jombe... (2 Replies)
Discussion started by: pchangba1
2 Replies
7. Red Hat
Can someone explain what is the status says WAIT on performance monitoring
command.. (2 Replies)
Discussion started by: suresh_krish
2 Replies
8. Shell Programming and Scripting
Hi Gurus,
Some questions regarding wait. I have tried searching in this forum for threads on wait but not completely got what I am looking for.
Background:
One script (.sh) that starts/calls a reference to an application's executable and submits a batch job to it. Objective is to wait... (2 Replies)
Discussion started by: rsheikh
2 Replies
9. Shell Programming and Scripting
Hi,
I am facing a strange issue,
when i call a script from my while loop in background it doesnt go in background, despite the wait i put below the whil loop it goes forward even before the process put in background is completed.
cat abc.txt | while read -u4 line
do
#if line contains #... (2 Replies)
Discussion started by: mihirvora16
2 Replies
10. Shell Programming and Scripting
Hi,
written a script which uses wait as follows
Main.sh
#!/usr/bin/ksh
nohup scrpit1 1 &
pid_1=$!
nohup scrpit1 2 &
pid_2=$!
wait $pid_1
wait $pid_2
nohup scrpit1 3 &
pid_1=$!
nohup scrpit1 4 & (1 Reply)
Discussion started by: krux_rap
1 Replies
preap(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(3C),
waitid(2), or waitpid(3C) 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(3C) 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:
o The process is a child of init(1M).
o The parent process is stopped and might wait on the child when it is again allowed to run.
o 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) |
+-----------------------------+-----------------------------+
SEE ALSO
proc(1), init(1M), waitid(2), wait(3C), waitpid(3C), proc(4), attributes(5)
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 5.10 26 Mar 2001 preap(1)