tablizer/cmd/tablizer.go

package cmd
var manpage = `
NAME
    tablizer - Manipulate tabular output of other programs

SYNOPSIS
        Usage:
          tablizer [regex] [file, ...] [flags]
    
        Flags:
          -c, --columns string     Only show the speficied columns (separated by ,)
          -d, --debug              Enable debugging
          -h, --help               help for tablizer
          -v, --invert-match       select non-matching rows
          -m, --man                Display manual page
          -n, --no-numbering       Disable header numbering
          -N, --no-color           Disable pattern highlighting
          -o, --output string      Output mode - one of: orgtbl, markdown, extended, ascii(default)
          -X, --extended           Enable extended output
          -M, --markdown           Enable markdown table output
          -O, --orgtbl             Enable org-mode table output
          -s, --separator string   Custom field separator
          -v, --version            Print program version

DESCRIPTION
    Many programs generate tabular output. But sometimes you need to
    post-process these tables, you may need to remove one or more columns or
    you may want to filter for some pattern (See PATTERNS) or you may need
    the output in another program and need to parse it somehow. Standard
    unix tools such as awk(1), grep(1) or column(1) may help, but sometimes
    it's a tedious business.

    Let's take the output of the tool kubectl. It contains cells with
    withespace and they do not separate columns by TAB characters. This is
    not easy to process.

    You can use tablizer to do these and more things.

    tablizer analyses the header fiels of a table, registers the column
    positions of each header field and separates columns by those positions.

    Without any options it reads its input from "STDIN", but you can also
    specify a file as a parameter. If you want to reduce the output by some
    regular expression, just specify it as its first parameter. You may also
    use the -v option to exclude all rows which match the pattern. Hence:

       # read from STDIN
       kubectl get pods | tablizer

       # read a file
       tablizer filename

       # search for pattern in a file (works like grep)
       tablizer regex filename

       # search for pattern in STDIN
       kubectl get pods | tablizer regex

    The output looks like the original one but every header field will have
    a numer associated with it, e.g.:

       NAME(1) READY(2) STATUS(3) RESTARTS(4) AGE(5)

    These numbers denote the column and you can use them to specify which
    columns you want to have in your output:

       kubectl get pods | tablizer -c1,3

    You can specify the numbers in any order but output will always follow
    the original order.

    The numbering can be suppressed by using the -n option.

    By default, if a pattern has been speficied, matches will be
    highlighted. You can disable this behavior with the -N option.

    Finally the -d option enables debugging output which is mostly usefull
    for the developer.

  PATTERNS
    You can reduce the rows being displayed by using a regular expression
    pattern. The regexp is PCRE compatible, refer to the syntax cheat sheet
    here: <https://github.com/google/re2/wiki/Syntax>. If you want to read a
    more comprehensive documentation about the topic and have perl installed
    you can read it with:

        perldoc perlre

    Or read it online: <https://perldoc.perl.org/perlre>.

    A note on modifiers: the regexp engine used in tablizer uses another
    modifier syntax:

        (?MODIFIER)

    The most important modifiers are:

    "i" ignore case "m" multiline mode "s" single line mode

    Example for a case insensitve search:

        kubectl get pods -A | tablizer "(?i)account"

  OUTPUT MODES
    There might be cases when the tabular output of a program is way too
    large for your current terminal but you still need to see every column.
    In such cases the -o extended or -X option can be usefull which enables
    *extended mode*. In this mode, each row will be printed vertically,
    header left, value right, aligned by the field widths. Here's an
    example:

        kubectl get pods | ./tablizer -o extended
            NAME: repldepl-7bcd8d5b64-7zq4l  
           READY: 1/1    
          STATUS: Running  
        RESTARTS: 1 (71m ago)  
             AGE: 5h28m

    You can of course still use a regex to reduce the number of rows
    displayed.

    The option -o shell can be used if the output has to be processed by the
    shell, it prints variable assignments for each cell, one line per row:

        kubectl get pods | ./tablizer -o extended ./tablizer -o shell
        NAME="repldepl-7bcd8d5b64-7zq4l" READY="1/1" STATUS="Running" RESTARTS="9 (47m ago)" AGE="4d23h" 
        NAME="repldepl-7bcd8d5b64-m48n8" READY="1/1" STATUS="Running" RESTARTS="9 (47m ago)" AGE="4d23h" 
        NAME="repldepl-7bcd8d5b64-q2bf4" READY="1/1" STATUS="Running" RESTARTS="9 (47m ago)" AGE="4d23h"

    You can use this in an eval loop.

    Beside normal ascii mode (the default) and extended mode there are more
    output modes available: orgtbl which prints an Emacs org-mode table and
    markdown which prints a Markdown table.

BUGS
    In order to report a bug, unexpected behavior, feature requests or to
    submit a patch, please open an issue on github:
    <https://github.com/TLINDEN/tablizer/issues>.

LICENSE
    This software is licensed under the GNU GENERAL PUBLIC LICENSE version
    3.

    Copyright (c) 2022 by Thomas von Dein

    This software uses the following GO libraries:

    repr (https://github.com/alecthomas/repr)
        Released under the MIT License, Copyright (c) 2016 Alec Thomas

    cobra (https://github.com/spf13/cobra)
        Released under the Apache 2.0 license, Copyright 2013-2022 The Cobra
        Authors

AUTHORS
    Thomas von Dein tom AT vondein DOT org

`