Getting the Value of a single hash key

[Anonymous Monk]

Hello Monks,

I'm trying to finish a simple script that first builds a key/value hash. I will then query the hash to test the equality of a value with a new given value.

I don't understand why this doesn't work:

if(($hash{$key}) eq $value)

Any ideas?

while ($line = <F>) 
{
  chomp($line);
  ($value, $key) = split(/=/, $line);

  if(exists $hash{$key})
  {
     if(($hash{$key})  eq $value)
     {
        print "YES: ", ($hash{$key}) ," == $value\n";
     }
     else 
     {
        print "NOT: ",  ($hash{$key}) ," != $value\n";
      }
  } 
}

[pzbagel]

Ahh, you don't need to use push, you can change the line:

push( @{$hash{$key}}, $src);

to:

$hash{$key}=$src;

And all should be well.

Good Luck

[jeffa]

($value, $key) = split(/=/, $line);

Since the key is usually on the left side of the equal sign, shouldn't that be:

($key, $value) = split(/=/, $line);

I changed that line and your code worked for my test case.

UPDATE: regarding your reply below, please show us what your data looks like. That is, what are the contents of the F filehandle?

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

[Anonymous Monk]

I know, but the file I have is formatted value=key. So that is correct. The problem is that I get this output:

NOT: ARRAY(0x1a99a98)  != Source1
NOT: ARRAY(0x1a752ec)  != Source2
NOT: ARRAY(0x1a99a98)  != Source3

[ChrisS]

You may be building your hash incorrectly, because it looks like the values are array references. Could you post that code?

[pzbagel]

That ouput you gave us is enlightening. It suggests that when you are putting the %hash hash together, you are inserting array references instead of the values you are expecting. I suspect that in the code that is inserting the key/value pairs into %hash, you need to dereference the value. If you can't find the error, post the portion of your code that assigns the key/value pairs to %hash and we can help you.

Cheers

[dogz]

Here is the code:

my $path;

my %hash = ();  #created items/objects
my $line;

while ($line = <CREATEFILE>) 
{
  
  chomp($line);
                 
  ($src, $key) = split (/=/, $line);
  push( @{$hash{$key}}, $src);
   
}

[dogz]

Here is an example of the data. The second file handle does not have unique keys so I can't build a hash to test with it.

There are two source files:

#Listings  Filehandle <CREATEFILE>
Source1=Times
Source2=DJNews
Source3=Yahoo

#Repeat Stocks  Filehandle <F>
F=Source1
F=Source3
LNUX=Source2
AMZN=Source1
INTL=Source3
INTL=Source1