NAME
    App::td - Manipulate table data

VERSION
    This document describes version 0.101 of App::td (from Perl distribution
    App-td), released on 2020-11-08.

FUNCTIONS
  td
    Usage:

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

    Manipulate table data.

    *td* receives table data from standard input and performs an action on
    it. It has functionality similar to some Unix commands like *head*,
    *tail*, *wc*, *cut*, *sort* except that it operates on table
    rows/columns instead of lines/characters. This is convenient to use with
    CLI scripts that output table data.

    A *table data* is JSON-encoded data in the form of either: "hos" (hash
    of scalars, which is viewed as a two-column table where the columns are
    "key" and "value"), "aos" (array of scalars, which is viewed as a
    1-column array where the column is "elem"), "aoaos" (array of arrays of
    scalars), or "aohos" (array of hashes of scalars).

    The input can also be an *enveloped* table data, where the envelope is
    an array: "[status, message, content, meta]" and "content" is the actual
    table data. This kind of data is produced by "Perinci::CmdLine"-based
    scripts and can contain more detailed table specification in the "meta"
    hash, which "td" can parse.

    First you might want to use the "info" action to see if the input is a
    table data:

     % osnames -l --json | td info

    If input is not valid JSON, a JSON parse error will be displayed. If
    input is valid JSON but not a table data, another error will be
    displayed. Otherwise, information about the table will be displayed
    (form, number of columns, column names, number of rows, and so on).

    Next, you can use these actions:

     # List available actions
     % td actions

     # Convert table data (which might be hash, aos, or aohos) to aoaos form
     % list-files -l --json | td as-aoaos

     # Convert table data (which might be hash, aos, or aoaos) to aohos form
     % list-files -l --json | td as-aohos

     # Display table data on the browser using datatables (to allow interactive sorting and filtering)
     % osnames -l | td cat --format html+datatables

     # Convert table data to CSV
     % list-files -l --json | td as-csv

     # Calculate arithmetic average of numeric columns
     % list-files -l --json | td avg

     # Append a row at the end containing arithmetic average of number columns
     % list-files -l --json | td avg-row

     # Count number of columns
     % osnames -l --json | td colcount

     # Append a single-column row at the end containing number of columns
     % osnames -l --json | td colcount-row

     # Return the column names only
     % lcpan related-mods Perinci::CmdLine | td colnames

     # append a row containing column names
     % lcpan related-mods Perinci::CmdLine | td colnames-row

     # Only show first 5 rows
     % osnames -l --json | td head -n5

     # Show all but the last 5 rows
     % osnames -l --json | td head -n -5

     # Check if input is table data and show information about the table
     % osnames -l --json | td info

     # Count number of rows
     % osnames -l --json | td rowcount
     % osnames -l --json | td wc            ;# shorter alias

     # Append a single-column row containing row count
     % osnames -l --json | td rowcount-row
     % osnames -l --json | td wc-row        ;# shorter alias

     # Add a row number column (1, 2, 3, ...)
     % list-files -l --json | td rownum-col

     # Select some columns
     % osnames -l --json | td select value description

     # Select all columns but some
     % osnames -l --json | td select '*' -e value -e description

     # Return the rows in a random order
     % osnames -l --json | td shuf

     # Pick 5 random rows from input
     % osnames -l --json | td shuf -n5

     # Sort by column(s) (add "-" prefix to for descending order)
     % osnames -l --json | td sort value tags
     % osnames -l --json | td sort -- -value

     # Return sum of all numeric columns
     % list-files -l --json | td sum

     # Append a sum row
     % list-files -l --json | td sum-row

     # Only show last 5 rows
     % osnames -l --json | td tail -n5

     # Show rows from the row 5 onwards
     % osnames -l --json | td tail -n +5

     # Transpose table (make first column of rows as column names in the transposed
     # table)

     % osnames -l --json | td transpose

     # Transpose table (make columns named 'row1', 'row2', 'row3', ... in the
     # transposed table)

     % osnames -l --json | td transpose --no-header-column

     # Use Perl code to filter rows. Perl code gets row in $row or $_
     # (scalar/aos/hos) or $rowhash (always a hos) or $rowarray (always aos). There
     # are also $rownum (integer, starts at 0) and $td (table data object). Perl
     # code is eval'ed in the 'main' package with strict/warnings turned off. The
     # example below selects videos that are larger than 480p.

     % media-info *.mp4 | td grep 'use List::Util qw(min); min($I<< ->{video >>height}, $I<< ->{video >>width}) > 480'

     # Use Perl code to filter columns. Perl code gets column name in $colname or
     # $_. There's also $colidx (column index, from 1) and $td (table data object).
     # If table data form is 'hash' or 'aos', it will be transformed into 'aoaos'.
     # The example below only select even columns that match /col/i. Note that most
     # of the time, 'td select' is better. But when you have a lot of columns and
     # want to select them programmatically, you have grep-col.

     % somecd --json | td grep-col '$colidx % 2 == 0 && /col/i'

     # Use Perl code to transform row. Perl code gets row in $row or $_
     # (scalar/hash/array) and is supposed to return the new row. As in 'grep',
     # $rowhash, $rowarray, $rownum, $td are also available as helper. The example
     # below adds a field called 'is_landscape'.

     % media-info *.jpg | td map '$I<< ->{is >>landscape} = $I<< ->{video >>height} < $I<< ->{video >>width} ? 1:0; $_'

     # Use perl code to sort rows. Perl sorter code gets row in $a & $b or $I<[0] &
     # $>[1] (hash/array). Sorter code, like in Perl's standard sort(), is expected
     # to return -1/0/1. The example belows sort videos by height, descendingly then
     # by width, descendingly.

     % media-info *.mp4 | td psort '$b->{video_height} <=> $a->{video_height} || $b->{video_width} <=> $b->{video_width}'

    This function is not exported.

    Arguments ('*' denotes required arguments):

    *   action* => *str*

        Action to perform on input table.

    *   argv => *array[str]* (default: [])

        Arguments.

    *   detail => *bool*

    *   exclude_columns => *array[str]*

    *   lines => *str*

    *   no_header_column => *true*

        Don't make the first column as column names of the transposed table;
        instead create column named 'row1', 'row2', ...

    *   repeat => *bool*

        Allow duplicates.

    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)

HOMEPAGE
    Please visit the project's homepage at
    <https://metacpan.org/release/App-td>.

SOURCE
    Source repository is at <https://github.com/perlancar/perl-App-td>.

BUGS
    Please report any bugs or feature requests on the bugtracker website
    <https://rt.cpan.org/Public/Dist/Display.html?Name=App-td>

    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
    Rinci::function for a more detailed explanation on enveloped result.

    TableDef for more detailed explanation of table data definition, which
    can be specified in enveloped result's `meta` hash in the `table` key
    (see Perinci::Sub::Property::result::table).

    TableData::Object

    Perinci::CmdLine

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2020, 2019, 2017, 2016, 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.

