IO::InnerFile(3) User Contributed Perl Documentation IO::InnerFile(3) NAME IO::InnerFile - define a file inside another file SYNOPSIS 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>) { # ... } DESCRIPTION If you have a file handle that can "seek" and "tell", then you can open an IO::InnerFile on a range of the underlying file. CONSTRUCTORS IO::InnerFile implements the following constructors. new my $inner = IO::InnerFile->new($fh); $inner = IO::InnerFile->new($fh, 10); $inner = IO::InnerFile->new($fh, 10, 50); Create a new IO::InnerFile 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. METHODS IO::InnerFile implements the following methods. add_length $inner->add_length(30); Add to the virtual length of the inner file by the number given in bytes. add_start $inner->add_start(30); Add to the virtual position of the inner file by the number given in bytes. binmode $inner->binmode(); This is a NOOP method just to satisfy the normal IO::File interface. close fileno $inner->fileno(); This is a NOOP method just to satisfy the normal IO::File interface. flush $inner->flush(); This is a NOOP method just to satisfy the normal IO::File interface. get_end my $num_bytes = $inner->get_end(); Get the virtual end position of the inner file in bytes. get_length my $num_bytes = $inner->get_length(); Get the virtual length of the inner file in bytes. get_start my $num_bytes = $inner->get_start(); Get the virtual position of the inner file in bytes. getc getline print LIST printf read readline seek set_end $inner->set_end(30); Set the virtual end of the inner file in bytes (this basically just alters the length). set_length $inner->set_length(30); Set the virtual length of the inner file in bytes. set_start $inner->set_start(30); Set the virtual start position of the inner file in bytes. tell write AUTHOR Eryq (eryq@zeegee.com). President, ZeeGee Software Inc (http://www.zeegee.com). CONTRIBUTORS Dianne Skoll (dfs@roaringpenguin.com). COPYRIGHT & LICENSE 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. perl v5.30.2 2020-05-18 IO::InnerFile(3)