in reply to passing filename in subroutines

Are you trying to pass a filehandle to a subroutine? If so, there are a variety of methods you can use.

The first is, you can just not pass it. Filehandles are global. So you can just use it, like this: 

sub foo {
   open FILE, "file.txt";
   bar();
   close FILE;
}
sub bar {
   my @lines = <FILE>;
   # do something here
}

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Second, you can open the filehandle as a variable and pass that. This is probably the best method. 
sub foo {
   open my $file, "file.txt";
   bar($file);
   close $file;
}
sub bar {
   my ($file) = @_;
   my @lines = <$file>;
   # do something here
}

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Lastly, I think you can use a typeglob. But I'm not sure how, and it'll be ugly. My advice would be to forget that I even mentioned it and use one of the other methods. But it's there if you need it.

elusion : http://matt.diephouse.com

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Re: Re: passing filename in subroutines
by Hofmator (Curate) on Mar 04, 2003 at 11:36 UTC
    Lastly, I think you can use a typeglob. But I'm not sure how, and it'll be ugly.
    Depends on your definition of ugly ;-)

    It's not difficult either - taking up on your example: 

    sub foo {
  local *FILE;
  open FILE, "file.txt";
  bar(*FILE);
}
sub bar {
  my $file = shift;
  my @lines = <$file>;
  # do something here
}

    [download]

    Your alternative that's using the lexical variable as a filehandle is still the best, imho, but compared to not passing it and relying on the global variable, the typeglob approach is surely better - unless the script is very short and trivially simple. Btw, note my use of local to avoid clobbering the global filehandle FILE.

    -- Hofmator

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[d/l]
Re: Re: passing filename in subroutines
by snam (Novice) on Mar 04, 2003 at 04:12 UTC
    thx^^
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