perl使用带有多个键的哈希比较文件

Question

I have the following script with which I compare columns from two files using a hash.

But when there is a match between cols[5] from $conversion and cols[2] from $table, I want to print out the value from another column in $conversion, namely the corresponding value in cols[1]. I've tried to do this by assigning the value from cols[1] to a second key in my %hash, called $keyfield2. But I don't succeed in printing it. This is my code so far:

my %hash = ();
while(<$conversion>){
    chomp;
    my @cols = split(/\t/);
    my $keyfield = $cols[5];
    my $keyfield2 = $cols[1];
    $hash{$keyfield,$keyfield2}++;
    }
seek $table,0,0; #cursor resetting
while(<$table>){
    my @cols = split(/\t/); 
    my $keyfield = $cols[2]; 
    if (exists($hash{$keyfield})){
        print $output "$cols[0]","\t","$hash{$keyfield2}","\t","$cols[1]\n";
    }
}

Any hints on how to do this?

Answer 1

Is there a reason you use a hash reference. With a hash try this:

my $keyfield = $cols[5];
my $keyfield2 = $cols[1];
$hash{$keyfield} = $keyfield2

and the print to:

print $output "$cols[0]","\t","$hash{$keyfield}","\t","$cols[1]\n";