Allright, let's put it straight, I don't like to write other's code as I don't like others to write the code I'm in charge with. But, having said that, and having talk with qball in the CB, his problem was more interresting than it first sounded as he couldn't use a proper database to do the job (which obviously, would have been the best solution)

So, after having toyed with the idea of using DBD::RAM, it seemed that this very cool module wasn't able to fill the task (which I doubt, but I haven't tried to do it with it...)

So, here's my code:

#!/usr/bin/perl -w
use strict;
my $datas = {};
my %types;

##open needed files to use in program
    open(NAMES, "file1.csv") 
          or die "Can't open NAMES file: $!\n";
    open(TYPES, "file2.csv")
          or die "Can't open TYPES file: $!\n";
    open(INFO,  "file3.csv")
          or die "Can't open INFO file: $!\n";

# Process INFO
while (<INFO>){
    chomp;
    my ($unused_col, $type_name, $name_col) = split(/,/, $_, 3);
    $types{$type_name} = undef; # We never knows from this table where
+ 
                                  # these fields are linked from?
}
close INFO;

# Process NAMES
while (<NAMES>){
    chomp;
    my ($name_id, $c_name) = split(/,/, $_, 2);
    $datas->{$name_id} = {'c_name' => $c_name }    # provided the id i
+s unique
}
close NAMES;

# Process TYPES
while (<TYPES>){
    chomp;
    my ($type_id, $name_id, $type_name) = split(/,/, $_, 3);
    push @{$datas->{$name_id}->{'type_name'}}, $type_name;

    # Not sure if we have to test the existence of the type.
    # Can't hurt too much (and avoid undesired autovivification?)
    $types{$type_name}++ if exists $types{$type_name};
}
close TYPES;

# Not seen output
print "Not seen:\n";
foreach (keys %types){
    print "$_\n" unless $types{$_}
}

# Names count
print "Names total count:\n";
foreach (keys %{$datas}){
    print $datas->{$_}->{'c_name'} . ": " .
      scalar(@{$datas->{$_}->{'type_name'}}) . "\n";
}
[download]

I guess there's a cleaner implementation of this. Mmmh, well I'll get back to DBD::RAM, I'm pretty sure it could do the job just fine...

Cheers,
-- Briac

Thanks Oeuf, I didn't expect you to write up the code. Many thanks for that. Very nice code indeed. I have one question though, when I run the script against the example data my output is this:

Not seen:
UUUU
IWEJ
Names total count:
booya: 3
letterheadboy: 2

Shouldn't "letterheadboy" have 4 results? Again, many thanks.

supersplit_open(',',"file1.csv"); would give you all your data in a 2D-array. Saves a few keystrokes.

Jeroen
"We are not alone"(FZ)

I see where there's a DBD::CSV available on CPAN ...

Philosophy can be made out of anything. Or less -- Jerry A. Fodor

urgh..it's not homework...here's my example script...please help...



#!/usr/bin/perl

##BILLING PROGRAM##

use strict;

my(@data,@data2);
##open needed files to use in program

    open(FILE, "../Counts/newdata.txt")
                or die "Can't open file: $!\n";
    open(FILE2, "../Counts/info.csv")
                or die "Can't open file: $!\n";

##throw files into arrays and define arrays

    chomp(@data = <FILE>);
    chomp(@data2 = <FILE2>);

##define hash
my ($id,$name,$srid);

    my %keyhash = ( $id => { NAME => $name,
            SRID  => $srid,
            CSV => []
            }
            );

##populate arrays: 

    foreach ( @data ) {

    ##define variables
    my ($id,$name,$srid) = split /,/;

    # Add some error checking to make sure the
    # hash key $id does not already exist

    $keyhash{$id} = { NAME => $name,
            SRID  => $srid,
            CSV => [],
        }
    }

##print unused ids from csv file

    print "\n\nUnused ids from csv file\n";
    print "--------------------------\n";

    foreach ( @data2 ) {
        my ($id,$name,$srid) = split /,/;

        # Warn and do nothing if a record is found for which the
        # $name is not already in %keyhash
    
        unless ( defined( $keyhash{$name} ) ) {
            warn "No such record $id!\n";
        next;
        }
  
    push @{$keyhash{$id}{CSV}}, [ $name, $srid ];
    }

##Finally, extract the number of records for each customer 

##print column headers

    print "\n\n";
    print "Customer    #of docs\n";
    print "-------------------------\n";

# A little something to get the plurality correct

    foreach ( keys %keyhash ) {
        my $num = @{$keyhash{$_}{CSV}};
        printf "%s        %d\n",
        $keyhash{$_}{NAME}, 
    $num,
    }

##just formatting by adding a couple returns at the end of the printou
+t

    print "\n\n";

##my choice of data structures ( hashes instead of arrays ) is dependa
+nt 
##on how we want to use the data later.

##close files

    close (FILE);
    close (FILE2);

##exit program

    exit;
[download]



Here it is. Thanks for beating me up :) ..