IO::InnerFile - define a file inside another file
use strict;
use warnings;
use IO::InnerFile;
# Read a subset of a file:
my $fh = _some_file_handle;
my $start = 10;
my $length = 50;
my $inner = IO::InnerFile->new($fh, $start, $length);
while (my $line = <$inner>) {
# ...
}
If you have a file handle that can seek and tell, then you
can open an the IO::InnerFile manpage on a range of the underlying file.
the IO::InnerFile manpage implements the following constructors.
my $inner = IO::InnerFile->new($fh);
$inner = IO::InnerFile->new($fh, 10);
$inner = IO::InnerFile->new($fh, 10, 50);
Create a new the IO::InnerFile manpage opened on the given file handle.
The file handle supplied MUST be able to both seek and tell.
The second and third parameters are start and length. Both are defaulted
to zero (0). Negative values are silently coerced to zero.
the IO::InnerFile manpage implements the following methods.
$inner->add_length(30);
Add to the virtual length of the inner file by the number given in bytes.
$inner->add_start(30);
Add to the virtual position of the inner file by the number given in bytes.
$inner->binmode();
This is a NOOP method just to satisfy the normal the IO::File manpage interface.
$inner->fileno();
This is a NOOP method just to satisfy the normal the IO::File manpage interface.
$inner->flush();
This is a NOOP method just to satisfy the normal the IO::File manpage interface.
my $num_bytes = $inner->get_end();
Get the virtual end position of the inner file in bytes.
my $num_bytes = $inner->get_length();
Get the virtual length of the inner file in bytes.
my $num_bytes = $inner->get_start();
Get the virtual position of the inner file in bytes.
$inner->set_end(30);
Set the virtual end of the inner file in bytes (this basically just alters the length).
$inner->set_length(30);
Set the virtual length of the inner file in bytes.
$inner->set_start(30);
Set the virtual start position of the inner file in bytes.
Eryq (eryq@zeegee.com).
President, ZeeGee Software Inc (http://www.zeegee.com).
Dianne Skoll (dfs@roaringpenguin.com).
Copyright (c) 1997 Erik (Eryq) Dorfman, ZeeGee Software, Inc. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
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