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SPAWN Multiple Processes in Unix

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# 1  
Old 11-02-2012
SPAWN Multiple Processes in Unix
Hi,

I have three files in my IN directory.Each file should be copied 25 times using for loop.Each file processing should run in parallel?How to spawn multiple processes in unix?Any help would be appreciated.

Thanks,
Liyakath
# 2  
Old 11-02-2012
Do you have more clues ?
Are they going to be copied 25 times at 25 differents destinations ?
# 3  
Old 11-02-2012
no,same destination.
# 4  
Old 11-02-2012
If it is to a single destination, why do you need to copy it 25 times instead of just once?
# 5  
Old 11-02-2012
Please find below the code:

Code:
for i in `ls -lrt | sort | grep -v total | awk '{print \$NF}'` /list of files in    a    directory
do
  for j in {1..29}                    #29 times the files should be copied
  do
    echo "copying $i file to $outputdir"
    cp $i $HOME/$outputdir/$i.$j.inp    #copy each file as filename.$j.inp 
  done
done


Thanks,
Ali.
Last edited by Scott; 11-03-2012 at 11:34 AM.. Reason: Please find above code tags :)
# 6  
Old 11-02-2012
1) Did you set the outputdir variable ?
2) Can't you just : for i in `ls -rt` instead of for i in `ls -lrt | sort | grep -v total | awk '{print $NF}'`

(It doesn't really make sens to make a "sort" on an 'ls -lrt' output ...)
Last edited by ctsgnb; 11-02-2012 at 02:04 PM..
# 7  
Old 11-02-2012
If you're doing ls | grep | awk | sed | kitchen | sink, you can probably just do it all in awk and save yourself a lot of performance.

That's also a useless use of backticks. It's almost always better to use a while-read loop if possible.

Code:
ls -rt | while read i
do
        for j in {1..29} #29 times the files should be copied
        do
                echo "copying $i file to $outputdir"
                cp $i $HOME/$outputdir/$i.$j.inp #copy each file as filename.$j.inp
        done
done
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