Hi all,
I am working on a script where u read multiple files from a folder after applying filter on the name of the file. And I write this in a single file.

Now I need to speed things up i wish to split the whole process in no of instances. I wrote the following code, but am not able to get the expected result.
use strict;

use warnings;


opendir DATDIR, "dats/";

my @files = grep { $_ ne '.' && $_ ne '..' } readdir (DATDIR);

my $dat = "dats/";

#my @files = <$dat/*.*>;

my @datfiles = sort {$a cmp $b} @files;

my @print = "";

my $toNumofFiles = @datfiles;

my $instance = 5;

my $report = "2010_01";



my $filesperinstance;

my $remainingfiles;

my $print;



if($toNumofFiles < $instance)

{

    $filesperinstance =1;

    $instance = $toNumofFiles;

}

else

{

    $filesperinstance= $toNumofFiles / $instance;

    $remainingfiles = $toNumofFiles % $instance;

}



my @childs = ();

my $startArrayIndex = 0;

my $endArrayIndex=$filesperinstance;




for(1..$instance)

{

    if ($remainingfiles !=0)

    {

        $endArrayIndex =  $endArrayIndex + 1;

        $remainingfiles = $remainingfiles -1;

    }

    my $pid = fork();

    

    if($pid)

    {

        push(@childs,$pid);

    }

    elsif($pid==0)

    {

        my $locStartArrayIndex = $startArrayIndex;

            my $locEndArrayIndex = $endArrayIndex;

        

        for (my $fileIndex = $locStartArrayIndex; $fileIndex < $locEnd
+ArrayIndex; $fileIndex++)

        {

            if($datfiles[$fileIndex] =~ m/^$report/)

            {

                print $datfiles[$fileIndex],"\n\n";                
                my $datDir = "dats/$datfiles[$fileIndex]";
                print $datDir,"\nDat Dir\n";

                read FILE, "< $datDir";
                @print = <FILE>;

            }        

        }

        exit(0);

    }

    else 

    {

       

        exit;

    }

    $startArrayIndex = $endArrayIndex;

    $endArrayIndex = $endArrayIndex + $filesperinstance;
print $_,"\ninstance \n";

}

foreach(@childs)
{
    waitpid($_,0);
}

print @print,"\nPrint\n";

[download]


I am getting this error 
Can't modify string in read at try.pl line 62, near ""< $datDir";"
Not enough arguments for read at try.pl line 62, near ""< $datDir";"
Execution of try.pl aborted due to compilation errors.

[download]
Kindly tell me where I going wrong?

Thanks
AvantA

In reply to how do I create parrallel processing in this script? by avanta

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