in reply to Re^2: Passing a file handle to a sub. I still don't get it.
in thread Passing a file handle to a sub. I still don't get it.

What exactly do you have in the <> brackets? Can you post the code?

Also, now that you're using IO::File you can use its getline method instead of angle brackets to do linewise input. This eliminates the ambiguity with file globbing. See the docs for IO::File parent class, IO::Handle.

the lowliest monk

  • Comment on Re^3: Passing a file handle to a sub. I still don't get it.

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Re^4: Passing a file handle to a sub. I still don't get it.
by rvosa (Curate) on Jun 09, 2005 at 19:10 UTC
    Okay, so here's the whole code. This sub is the one calling the parser:
    sub parse { my $self = shift; my @opts = @_; my %opts; if ( ! @opts || scalar @opts % 2 ) { $self->COMPLAIN("bad number of arguments."); return; } else { %opts = @opts; if ( ! $opts{-format} || ! grep(ucfirst($opts{-format}), @pars +ers) ) { $self->COMPLAIN("no valid format specified."); return; } if ( $opts{-file} && ( ! -T $opts{-file} || ! -r $opts{-file} +) ) { $self->COMPLAIN("file not found, not a text file, or not r +eadable"); return; } elsif ( ! $opts{-file} && ! $opts{-string} ) { $self->COMPLAIN("no data source specified."); return; } my $lib = ref $self; $lib .= '::' . ucfirst($opts{-format}); eval "require $lib"; my $parser = new $lib; if ( $opts{-file} && $parser->can('from_handle') ) { open(FH, $opts{-file}); $opts{-handle} = \*FH; return $parser->from_handle(%opts); } if ( $opts{-string} && $parser->can('from_string') ) { return $parser->from_string(%opts); } $self->COMPLAIN("the parser can't handle the data source speci +fied"); return; } }
    The call is 9 physical lines from the bottom. And here's the one who gets called:
    sub from_handle { my $self = shift; my %opts = @_; my $taxa = new Phylo::Taxa; my $version = $self->VERSION; while (<$opts{-handle}>) { if ( $_ ) { my $taxon = new Phylo::Taxa::Taxon; my $date = localtime; my $description = qq{Read from $opts{-file} using Phylo ve +rsion $version on $date}; $taxon->name($_); $taxon->desc($description); $taxa->insert($taxon); } } return $taxa; }
    And in the second block $_ == GLOB(0xa0bb570).

      What happens if you replace the while line in from_handle with

      while ( defined( $_ = $opts{-handle}->getline ) ) {
      ?

      the lowliest monk