topic Re: About copy file in Operating System - HP-UX

About copy file

peterchu — Sun, 16 May 2004 22:23:36 GMT

We have two batch jobs , one batch job is rcp a file from remote site to /tmp , and another batch job is to move this file to other directory , but I found that sometimes the second batch job (move file) is processing while it is still copying from remote site , therefore , the file is not complete , could suggest is the best way to solve it ? thx.

Re: About copy file

Patrick Wallek — Sun, 16 May 2004 22:32:19 GMT

The best way would be to use something like fuser or lsof to make sure there are not any processes with the file open.

In your script do an 'fuser -u filename' and if anything is returned then sleep for a period of time and try again.

Re: About copy file

Naveej.K.A — Sun, 16 May 2004 22:35:26 GMT

hi,
how about putting both the commands in the same job???

with best wishes
Naveej

Re: About copy file

peterchu — Sun, 16 May 2004 22:39:54 GMT

thx replies, it can't put to the same batch job because the permission reason .

Re: About copy file

curt larson_1 — Sun, 16 May 2004 22:41:58 GMT

start second job later

check for the file size in second job, if the file size hasn't increased in last 20 seconds, it is probably done being copied

have first job creates a file once the rcp is finished saying it is done, second job doesn't copy file till rcp done file exists.

Re: About copy file

peterchu — Sun, 16 May 2004 23:10:41 GMT

thx suggestion , do you have the sample script for my reference .

thx

Re: About copy file

Kiyoshi Miyake — Sun, 16 May 2004 23:11:03 GMT

Hi,

simple resolution. you make lock file.
example:

---rcp.sh---
touch /tmp/during_rcp
rcp foo bar
rm /tmp/during_rcp
---

---mv.sh---
while [ -f /tmp/during_rcp ]
do
sleep 300
done
mv bar baz
---

or:
use lockf(2) ( see man page lockf ).
or:
chmod -r ...

Thanks.

Re: About copy file

KapilRaj — Sun, 16 May 2004 23:42:38 GMT

In my organisation we call it a special resource .. but in a way it will help you in this case as well .. this is about creating a common lock / special resource which enable the script to do it's task.

Something like script1 and script2 starts with ..
************
while [ -f /var/tmp/SPR_REMOTE_CP ]
do
echo Lock file present >> $LOGFILE
sleep 60
done
touch /var/tmp/SPR_REMOTE_CP #Taken exclusive access

rcp or mv bla bla ........ #Do the task

rm /var/tmp/SPR_REMOTE # Removes the lock

Regds,

Kaps

Re: About copy file

Bharat Katkar — Sun, 16 May 2004 23:48:02 GMT

Peterchu,
What i think is before using mv command check for the existing of the file first and if it exists then only try moving it. See if this works for you.

while true
do
if [ -f /tmp/filename ]
then
mv /tmp/filename /anotherdir
exit
else
sleep 10
fi
done

Re: About copy file

Bharat Katkar — Sun, 16 May 2004 23:53:16 GMT

Little clearance:
I have used "true" and "exit" that may not be suitable in your script so modify accordingly to your requirement.
This is just an example.

Re: About copy file

peterchu — Mon, 17 May 2004 05:38:02 GMT

thx all replies , I want to use lock to fix it , could suggest how to write a script to use it ? thx.

Re: About copy file

Michael D'Aulerio — Tue, 18 May 2004 08:12:48 GMT

Using a lock file to coordinate between the 2 cron jobs is a good idea. We have used them in the past. One caution. Sometimes one of the cron jobs will die and leave the lock file in place. You should have some mechanism to check for stale lock files and remove them.