We are trying to run a process in the background and in the process we call fork ;and wait for the child process to finish .We find that the died = wait(&status); happens after 10 seconds randomly and sometimes completes in time (within 1 sec)
This behavior is seen only when the program is run as a background process. With foreground the functionality is always within 1 sec.
Can anyone please suggest the reason for this random scheduling in Linux - Operating system is CentOS
Thanks in advance for any help
Thanks
Vishnu
Last edited by vbe; 06-23-2009 at 12:15 PM..
Reason: added code tag + rm fancy URL...
I am attempting within a for-loop, to have my shell script (Solaris v8 ksh) wait until a copy file command to complete before continueing. The specific code is:
for files in $(<inputfile.lst)
do
mv directory/$files directory/$files
ksh -m -i bg %%
wait $!
done
I am shaky on the... (3 Replies)
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)
Hi
I have a shell script A which calls another 10 shell scripts which run in background. How do i make the parent script wait for the child scripts complete, or in other words, i must be able to do a grep of parent script to find out if the child scripts are still running.
My Code:
... (1 Reply)
can a wait command be run in background? or the script which has the wait command, be run background?
test.sh
-------
nohup a.sh &
nohup b.sh &
wait
nohup test.sh &
How can i run either wait or test.sh in background? i want test.sh to wait till a.sh and b.sh complete, and must be... (1 Reply)
Hi..
I was unable to do (gcc code) which refers to the fork,wait,sleep and write..
what i want to do:
A process of father create (fork) a son and will sleep 90 seconds..After this, son process create a grandchild and will sleep 60 seconds..Grandchild process will sleep for 30 seconds..After... (3 Replies)
hi all,
We are trying to run a process in the background and in the process we call fork ;and wait for the child process to finish .We find that the died = wait(&status); happens after 10 seconds randomly and sometimes completes in time (within 1 sec)
This behavior is seen only when the... (1 Reply)
Hi All,
I have two ksh script. 1st script calls the 2nd script and the second script calls an 'C' program.
I want 1st script to wait until the 'C' program completes.
I cant able to get the process id for the 'C' program (child process) to make the 1st script to wait for the second... (7 Replies)
Hello everybody.I want to make clear that i am not going to ask from anybody to build my asignement but i have a big problem. I can't seem to find anywhere ONE good example on C about what i am trying to do:wall:.I think it is simple. All i ask is one example, even a link is fine.
So, i want to... (1 Reply)
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)
Hi All,
I have a program for class that needs to do the following:
1. Print the directory entries from the current directory using ncurses
2. Provide a prompt next to each directory entry and allow the user to enter commands that may or may not be about the file
3. Execute those commands in... (1 Reply)
Discussion started by: afulldevnull
1 Replies
LEARN ABOUT V7
wait
WAIT(2) System Calls Manual WAIT(2)NAME
wait - wait for process to terminate
SYNOPSIS
wait(status)
int *status;
wait(0)DESCRIPTION
Wait causes its caller to delay until a signal is received or one of its child processes terminates. If any child has died since the last
wait, return is immediate; if there are no children, return is immediate with the error bit set (resp. with a value of -1 returned). The
normal return yields the process ID of the terminated child. In the case of several children several wait calls are needed to learn of all
the deaths.
If (int)status is nonzero, the high byte of the word pointed to receives the low byte of the argument of exit when the child terminated.
The low byte receives the termination status of the process. See signal(2) for a list of termination statuses (signals); 0 status indi-
cates normal termination. A special status (0177) is returned for a stopped process which has not terminated and can be restarted. See
ptrace(2). If the 0200 bit of the termination status is set, a core image of the process was produced by the system.
If the parent process terminates without waiting on its children, the initialization process (process ID = 1) inherits the children.
SEE ALSO exit(2), fork(2), signal(2)DIAGNOSTICS
Returns -1 if there are no children not previously waited for.
ASSEMBLER
(wait = 7.)
sys wait
(process ID in r0)
(status in r1)
The high byte of the status is the low byte of r0 in the child at termination.
WAIT(2)