NAME
File::Random::Pick - Pick random lines from a file, without duplicates
VERSION
This document describes version 0.03 of File::Random::Pick (from Perl
distribution File-Random-Pick), released on 2019-09-15.
SYNOPSIS
use File::Random::Pick qw(random_line);
my $line = random_line("/usr/share/dict/words");
my @lines = random_line("/usr/share/dict/words", 3);
# also accepts a filehandle
my $line = random_line($fh);
DESCRIPTION
This module can return random lines from a specified file, without
duplicates.
Compared to "random_line()" from File::Random, this module does not
return duplicates. I have also submitted a ticket to incorporate this
functionality into File::Random [1]. File::Random::Pick also accepts a
filehandle, for convenience.
FUNCTIONS
random_line($path_or_handle [ , $num_lines ]) => list
Return random lines from a specified file (or filehandle). Will not
return duplicates (meaning, will not return the same line of the file
twice, but might still return duplicates if two or more lines contain
the same content). Will die on failure to open file. $num_lines defaults
to 1. If there are less than $num_lines available in the file, will
return just the available number of lines.
The algorithm used is from perlfaq ("perldoc -q "random line""), which
scans the file once. The algorithm is for returning a single line and is
modified to support returning multiple lines.
HOMEPAGE
Please visit the project's homepage at
<https://metacpan.org/release/File-Random-Pick>.
SOURCE
Source repository is at
<https://github.com/perlancar/perl-File-Random-Pick>.
BUGS
Please report any bugs or feature requests on the bugtracker website
<https://rt.cpan.org/Public/Dist/Display.html?Name=File-Random-Pick>
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
File::Random also provides "random_line()" which also uses a slightly
modified version of the algorithm described in perlfaq ("perldoc -q
"random line"") that avoids slurping the whole file into memory in
exchange for scanning the whole file once. However, it might return
duplicates.
File::RandomLine
If you don't mind slurping the whole into memory, you can use
List::MoreUtils's "samples" to return N random items from a list. Or, if
you also don't mind duplicates, you can just pick random elements from
an array of lines.
[1] <https://rt.cpan.org/Ticket/Display.html?id=109384>
AUTHOR
perlancar <perlancar@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2019, 2015 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.