App::PickRandomLines - Pick one or more random lines from input


This document describes version 0.020 of App::PickRandomLines (from Perl distribution App-PickRandomLines), released on 2020-04-29.


See pick-random-lines.




 pick_random_lines(%args) -> [status, msg, payload, meta]

Pick one or more random lines from input.

TODO: * option to allow or disallow duplicates

This function is not exported.

Arguments ('*' denotes required arguments):

  • algorithm => str (default: "scan")

    scan is the algorithm described in the perlfaq manual (`perldoc -q "random line"). This algorithm scans the whole input once and picks one or more lines randomly from it.

    seek is the algorithm employed by the Perl module File::RandomLine. It works by seeking a file randomly and finding the next line (repeated n number of times). This algorithm is faster when the input is very large as it avoids having to scan the whole input. But it requires that the input is seekable (a single file, stdin is not supported and currently multiple files are not supported as well). Might produce duplicate lines.

  • files => array[filename]

    If none is specified, will get input from stdin.

  • num_lines => int (default: 1)

    If input contains less lines than the requested number of lines, then will only return as many lines as the input contains.

Returns an enveloped result (an array).

First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (payload) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information.

Return value: (any)


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