Print contents filehandle hash

Question

I have a hash (%filehandle) which stores filehandles as its values. But I can not print them.

My hash looks like this:

my %filehandle;
foreach my $output (@outputs){
  foreach my $fp (@fp_values_array){
    $filehandle{$output}{$fp}=undef;
    }
}
print Dumper \%filehandle;

$VAR1 = {

          'GMAF' => {
                      '0.05' => \*{'::$__ANONIO__'},
                      '1' => \*{'::$__ANONIO__'},
                      '0.001' => \*{'::$__ANONIO__'}
                    }
        };

I know that the problem is that the values are references but I'm starting with perl and I don't know how to acces to them...

I have tried something like this:

print "$_\n" for (keys ${$filehandle{GMAF}{$fp_value_array}});

But it doesn't work.

Type of argument to keys on reference must be unblessed hashref or arrayref at report.pl line 369, <INPUT> line 5000.

If someone can help me I would be very grateful.

Thanks in advanced!

What do you mean by 'you cannot print them'? Filehandles are references to an external file, socket, pipe, etc, that allow you to access them. You can not print them - but you can print TO them. Is that what you're asking? — Oesor, May 15 '14 at 15:41
but these filehandles, as you said, are references to a filename output, aren't they? My goal is printing these output files name. — userbio, May 15 '14 at 15:51
You use a name as one way to create a filehandle. A filehandle does not contain a name. It may be a reference to a socket, or a pipe, or something that does not have a filesystem name. Read http://stackoverflow.com/questions/2813092/can-i-find-a-filename-from-a-filehandle-in-perl - it can be done in some cases, but not always. — Oesor, May 15 '14 at 15:52

score 1 · Answer 1 · answered May 15 '14 at 15:44

1

print "$_\n" for (keys ${$filehandle{GMAF}{$fp_value_array}});

Should be:

for my $fp_value_array (keys %{$filehandle{GMAF}}) {
    print $filehandle{GMAF}{$fp_value_array};
}

Which dereferences the hashref stored in $filehandle{GMAF}, uses keys to get the keys of it, and iterates over the keys to stringify and print the reference to the filehandle value stored in each key.

answered May 15 '14 at 15:44

Oesor

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Thank you for the reply! I understand your point, but it is printing me glob references, these: GLOB(0xa45ef0)GLOB(0xa45e30)GLOB(0xa45fb0) – userbio May 15 '14 at 15:48
That's what filehandles are. – Oesor May 15 '14 at 15:49
my question is very wrongly formulated. I will try doing it by mylsef. Thank you @Oesor. – userbio May 15 '14 at 15:52

score 0 · Answer 2 · answered May 15 '14 at 16:28

File handles don't have file names associated with them. They wrap file descriptors. There are OS-specific ways of obtaining names from file descriptors (if any), but your best bet is to place the name in the hash along with the handle.

{
   GMAF => {
      '0.05' => {
         fn => ...,
         fh => ...,
      },
      '1' => {
         fn => ...,
         fh => ...,
      },
      '0.001' => {
         fn => ...,
         fh => ...,
      },
   },
}

Print contents filehandle hash

2 Answers2