NAME Tie::Array::File::LazyRead - Read a file record by record using tied array and for() VERSION This document describes version 0.001 of Tie::Array::File::LazyRead (from Perl distribution Tie-Array-File-LazyRead), released on 2019-04-16. SYNOPSIS Given FILENAME.txt containing: line1 line2 line3 Then this Perl script: use Tie::Array::File::LazyRead; tie my @ary, 'Tie::Array::File::LazyRead', 'FILENAME.txt', {accumulate=>1}; # default for accumulate is 0 for my $line (@ary) { print $line; } will print: line1 line2 line3 and @ary containing: ["line1", "line2", "line3"] If "accumulate" is set to 0 (the default), @ary will contain: [undef, undef, "line3"] (i.e. only the last element/line will be remembered. DESCRIPTION EXPERIMENTAL, PROOF-OF-CONCEPT. When "for()" is given a tied array: for (@tied_array) { ... } it will invoke "FETCHSIZE" on the tied array to find out the size, then FETCH(0), *then FETCHSIZE() again, then FETCH(1), and so on.* In other words, "FETCHSIZE" is called on each iteration. This makes it possible to only fetch new data in "FETCHSIZE" instead of "FETCH". Without using "for()": tie my @ary, 'Tie::Array::File::LazyRead', 'FILENAME.txt'; print $ary[0]; will not print anything, and the first line of the file is not fetched. To fetch one more line, you need to do: my $size = @ary; # then print $ary[0]; and so on. HOMEPAGE Please visit the project's homepage at <https://metacpan.org/release/Tie-Array-File-LazyRead>. SOURCE Source repository is at <https://github.com/perlancar/perl-Tie-Array-File-LazyRead>. BUGS Please report any bugs or feature requests on the bugtracker website <https://rt.cpan.org/Public/Dist/Display.html?Name=Tie-Array-File-LazyRe ad> When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature. SEE ALSO AUTHOR perlancar <perlancar@cpan.org> COPYRIGHT AND LICENSE This software is copyright (c) 2019 by perlancar@cpan.org. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.