Good evening Monks!
I am struggling to deal with a case when a hash key has two values. I have written a basic program to try and illustrate what I am trying to do.
fruit.txt 

apple
cherry
peach
banana
cherry

[download]
strands.txt 
apple    +
cherry    -
cherry    +
peach    +
banana    -

[download]
Using the fruit.txt file, I would like to be able to print 'cherry' if it is matched as positive, as well as if it is negative. Is there anyway I can do this in perl?
My program: 
#!/usr/bin/perl -w
use strict;
use Data::Dumper;

my $inputfile1 = $ARGV[0];
my $inputfile2 = $ARGV[1];
open (FILE1, $inputfile1) or die;
open (FILE2, $inputfile2) or die;

my @fruit = <FILE1>; # fruit.txt
close FILE1;

my @strands = <FILE2>; ## strands.txt
close FILE2;


my (@fruitcolumn, @strand_direction, %strands, $key, $value);
foreach my $line(@strands) { 
    my @colsplit = split("\t", $line);
    push (@fruitcolumn, $colsplit[0]);
    push (@strand_direction, $colsplit[1]);
    }

s/\s+$// foreach @strand_direction;
s/\s+$// foreach @fruit;
        
while ($key = shift (@fruitcolumn))
{
   $value = shift (@strand_direction);
   push @{$strands{$key}}, $value;
}

        
foreach my $line (@fruit) {

    if ($strands{$line} =~ m/\+/) {
    print "my positives are $line", "\n";
    }
    elsif($strands{$line} =~ m/\-/) {
    print "my negatives are $line", "\n";
    }
}

[download]
Any help would be gratefully received. - E

In reply to Unique key identifer? by lecb

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