Shell Programming and Scripting

I hope you guys can help me .
My requirement is as below:

Some data files will be ftped by other machine to my machine to the path /home/input
As soon as the file is ftped I need to zip it and move the file to /home/zipped path.

I can use the below command to zip
zip data.zip data.txt

but how do I find out that file is arrived to /home/input location

The file can arrive any time, so how do I keep watching for it all the day? Is there any command?

Thank you very much.

Sender machine can create empty file, right after main file is transfered. You can then monitor if this empty file exists

unfortunaly the sender will not send any empty file,
do I need to check for file using while (1) ?

Does /home/input directory ingeneral holds any other files ?

if not , you can do a "ls /home/input|wc -l" and can check the count , if count is zero --> it mean no files transfered , if not --> something arrived.

Regards
Ravi

Some FTP-servers are able to run scripts after uploads - check the documentation for your ftp-server.
I would try avoid a script with an endless loop but schedule a script via cron to run every minute.
If available on your system that script can use lsof (or a similar tool) to check for processes that have this file open (= upload in progress).

If the file is quite small, then you probably won't have to worry about a follow up file to flag completion, so using the -f flag for a test should suffice:-

Code:

while [ ! -f $file ]
do
   echo "`date`: File has not arrived"
   sleep 5
done

If the file is larger, you need to confirm that the whole file has arrived, consider using the fuser command to look at what has the file open:-

Code:

while [ ! -f $file ]
do
   echo "`date`: File has not arrived"
   sleep 5
done
while [ `fuser $file 2>/dev/null | wc -c` -gt 0 ]
do
   echo "`date`: File is arriving"
   sleep 5
done
echo "`date`: File has arrived.  Processing will continue."

The condition for the while loop ask for the processes accessing the file. The standard error is usually the file name, so this is ditched to /dev/null. We then count the bytes returned, so if there is anything there, a process has the file open. If it is zero, then there are no processes working on the file.



I hope that this helps, but please write back if I have missed the point.




Robin
Liverpool/Blackburn
UK

You can try something like this in order to find out if File has arrived :

Code:

while :
do
if [ "$(ls -A /path/to/monitor/)" ]; then
     echo "File has arrived"
fi
done