With the example you've been given there's a print statement within a while loop. Replace the print statement with the actions you wish to be taken, checking it's a text file, performing the operations you want. http://learn.perl.org, tutorials.

Since you mentioned File::Find ... Change the sub _SizeAndMD5 to suit your problem.

#!

use strict;
use warnings;
use File::Find;
use Digest::MD5::File;
no warnings "File::Find";
use Smart::Comments;

local *wanted=sub {
    if (-d $File::Find::name) { # directory
    }
    elsif ($File::Find::name =~ m{\.txt$}i) { # a file of interest
        print "for $File::Find::name - @{[_SizeAndMD5($File::Find::nam
+e)]}\n";
    }
}; # wanted
# Do something based on the file's content
local *_SizeAndMD5=sub {
    my ($filename_S)=@_;
    return (-e $filename_S ? sprintf("%8.8lx-%32.32s",-s $filename_S,D
+igest::MD5::File::file_md5_hex($filename_S)) : undef);
}; # _SizeAndMD5:
File::Find::find({ no_chdir=>1,wanted=>\&wanted },@ARGV);
exit;
[download]

This will process all of the files with a ".txt" extension below the directories specified by @ARGV.

Below code process each files in the /tmp directory. If any directory is inside the /tmp directory will not be processed

Add additional checking on file, like file size and readable permissions to avoid error.

#!/usr/bin/perl
use strict;
use warnings;

my $tmp_dir="/tmp/";

opendir (DIR, $tmp_dir) or die $!;
while (my $file_name = readdir(DIR))
{

    my $abs_path = $tmp_dir.$file_name;

    unless(-d $abs_path) #Ignore if it is a directory
    {   
        &Process_EachFile($abs_path); # Do call a function and process
+ each file
 }
    else
    {
        print "$abs_path is a directory\n";
    }

}
closedir(DIR);

sub Process_EachFile
{
    my ($filename) = @_;
    print $filename;
    open (FH,'<',"$filename") or die $!;
    while(my $each_line=<FH>)
    {
        print $each_line."\n";
        #Read file content here and do your calculation.
    }

}
[download]

Hi ree

I think I understand what you are trying to do, however when I run your script it crashes- "No such file or directory"

It has something to do with the

open (FH,'<',"$filename") or die $!;

line

Any advice?

Hi Dr Manhattan

when I run your script it crashes- "No such file or directory"

Could you please confirm that $filename variable contains the absolute path and not a relative path?

If no problem means you can put code here, I can debug for you.