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Opening files with hash array values

Griff
New User

Jul 31, 2011, 12:49 AM

Post #1 of 6 (1786 views)

Opening files with hash array values	Can't Post

Just wondering if someone can help me understand why the following doesn't work when trying to open files using Hash array values. Very frustrating.

my %FileHandles = (
SUBHIST => [$subscriberHist],
SUBDUPE => [$subscriberDupe],
SUBCLN => [$subscriberCln],
SUBDISC => [$subscriberDisc]
);

Open_Files(\%FileHandles);

sub Open_Files {
my $fileHandles = shift;
foreach $label (keys %{$fileHandles}) {
open (my $label, @{${$fileHandles}{$label}})
}
}

BillKSmith
Veteran

Jul 31, 2011, 5:35 AM

Post #2 of 6 (1773 views)

Re: [Griff] Opening files with hash array values [In reply to]	Can't Post

You need the first element of the array, not the whole array.

Code

  
 
        open( my $label, ${ ${$fileHandles}{$label} }[0] );

Good Luck,
Bill

FishMonger
Veteran / Moderator

Jul 31, 2011, 7:56 AM

Post #3 of 6 (1768 views)

Re: [Griff] Opening files with hash array values [In reply to]	Can't Post

What do each of those vars in %FileHandles hold? Are they simple scalars holding the full path to the file to be opened, or are they references to lists of file paths?

Why are you assigning them as array references?

Given the current initialization of the foreach loop, you can't use $label for the filehandle.

Since that hash doesn't contain filehandles, it doesn't make sense to name it that way. That only servers to confuse the reader as to what the hash holds.

Griff
New User

Jul 31, 2011, 3:47 PM

Post #4 of 6 (1722 views)

Re: [BillKSmith] Opening files with hash array values [In reply to]	Can't Post

Bill,

Many thanks, unfortunatley no good. I still get the same error.

Can't use string ("SUBDISC") as a SCALAR ref while "strict refs" in use at...

It keeps complaining about the file handle not the file itself.

Regards

Paul

Griff
New User

Jul 31, 2011, 3:52 PM

Post #5 of 6 (1721 views)

Re: [FishMonger] Opening files with hash array values [In reply to]	Can't Post

The values in %FileHandles are file lables and file names, not references.

The variables $subscriberHist etc contain file names not references.

When you say the hash doesn't contain file handles can you advise on how this should be done.

The error I keep getting is below.

Can't use string ("SUBDISC") as a SCALAR ref while "strict refs" in use...

FishMonger
Veteran / Moderator

Jul 31, 2011, 9:13 PM

Post #6 of 6 (1690 views)

Re: [Griff] Opening files with hash array values [In reply to]	Can't Post

Code

my %files = ( 
    SUBHIST => $subscriberHist, 
    SUBDUPE => $subscriberDupe, 
    SUBCLN  => $subscriberCln, 
    SUBDISC => $subscriberDisc, 
); 
 
my %file_handle; 
create_filehandles(\%files); 
 
sub create_filehandles { 
    my $files = shift; 
    foreach my $label ( keys %$files ) { 
        open $file_handle{$label}, '<', $files{label} 
          or die "can't open '$files{$label}' for reading $!"; 
    } 
}

(This post was edited by FishMonger on Jul 31, 2011, 9:14 PM)

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