Relational textfile?

[peppiv]

I have a pipe delimited text file. Looks like this:

Jimmy | yes | | | yes | yes | yes
Robert | yes | yes | | | |
JohnPaul | yes | yes | yes | yes | |
Bonzo | | | yes | yes | yes | |

How can I make a list from multiple field choices?
example - List 1 = those who have "yes" in field #2 but nothing in field #3
List 2 = those who have "yes" in field #2 and field #7
List 3 = "yes" in field #2, nothing in field #3, but yes in field #6

Oh, where to start? Please! I need help!

peppiv

[tilly]

Are you familiar with SQL? If so then I would suggest trying to use DBI together with either DBD::CSV or DBD::RAM as database drivers.

A side benefit is that when you are done it will be relatively little work to move your script to running against a real relational database.

[dash2]

Assuming that you never have pipes inside your data: (untested)

use strict;
my @list_defs = (
 {2 => 'yes', 3 => ''},
 {2 => 'yes', 7 => 'yes'},
 {2 => 'yes', 3 => '', 6 => 'yes'},
);
my @lists;
while (<FILE>) {
 my @vals = split /\|/;
 my $name = $vals[0];
 my $i = 0;
LIST: foreach my $l (@list_defs) {
  foreach (keys %$l) {
   next LIST unless $vals[$_] eq $l->{$_};
  }
  push $lists[$i], $name; # or \@vals;
  $i++;
 }
}

I'm sure there are quicker ways, and more readable ones.

dave hj~

[Akhasha]

I think the first comment is a really good bet. However I would have iterated over the file calling a selection function passed in as a reference. Think of the selection function as your query, if it returns true this name should go into the list you are building. An intermediate function to build a more friendly data structure for the selectors to operate on would be handy too.

[n3dst4]

I don't wan't to discourage you from using DBI, but if you wanted an alternative, and there isn't too much data, you could try reading in the data as a sort of pseudo-bitfield (untested and I've only just woken up...):

while (<IN>) {
    ($name, @fields) = split '|';
    for (0..5) { $value += 2**$_ if $fields[$_] }
    $people{$name} = $value;
}

# People with fields 0 and 3 but nothing else
for (keys %people) {
    print if $people{$_} ^ 58;
}