Fred, a front matter cli editor

Fred is a cli utility for precisely editing YAML-nodes inside the front matter of a markdown file.

Features

• Unset key
• Rename the key of a scalar node
• Replace string value of scalar node
• Toggle bool value of scalar node
• Scaler node at 1st level are automatically defined as variable
• Substitute variables inside scalar node when it's defined lines earlier
• Recursive mode for processing files inside directories
• Dry run mode

Installation

With Homebrew

1. brew tap mipmip/homebrew-crystal
2. brew install fred

From Source

1. git clone https://github.com/linden-project/fred
2. cd fred
3. make

Usage

  Options:

    --help                           Show this help.

  Sub Commands:

    echo                     echo display one node by key
    set_bool_val             Set boolean value for front matter key
    set_string_val           Set string value for front matter key
    unset_key                Remove key from front matter
    replace_key              Find and replace key in front matter
    replace_string_val       Find and replace a string value in front matter
    toggle_bool_val          Toggle a bool value in front matter, if true set false, if false or missing set true
    replace_1st_level_vars   replace variables found on 1st level in other levels in inside front matter
    replace_includes         replace includes inside front matter
    process_functions        replace $FORMAT and $INCLUDE inside front matter
    version                  version

Variable usage

Every scalar node as 1st level can be used as replace value inside lower of deeper scalar values. See example:

You have a file crystal-rules.md with the following contents.

---
title: Crystal Rules
category: Programming languages
date: "15 august 2019"
meta_info:
  abstract: $FORMAT This post is is written on {date} in the category {category}.
  file_name_pdf: $FORMAT /Users/mipmip/{date}-{title}.pdf
---

Did I tell you ...

When you run fred replace_1st_level_vars the file will look like this:

---
title: Crystal Rules
category: Programming languages
date: "15 august 2019"
meta_info:
  abstract: This post is is written on 15 august in the category Programming Languages.
  file_name_pdf: $FORMAT /Users/mipmip/15 august-Crystal Rules.pdf
---

Did I tell you ...

Example integration in Vim with Pandocomatic

nmap ,t :AsyncRun /usr/bin/fred replace_1st_level_vars -d % > /tmp/pandotemp.md && rvm 2.5.1 do pandocomatic -b -i /tmp/pandotemp.md<CR>

Syntax

Tag	Arguments	Example	Description
$FORMAT	String with vars inside {}	$FORMAT written by {author1} and {author2}	Replaces {author1} and {author2} with the values of the 1st level yaml keys author1: and author2:
$INCLUDE	Include path to YAML file	$INCLUDE ./blog_layout_config.yml	Imports external YAML at the include location. Path can be absolute or relative to the markdown file

Development

Run Specs

make run_spec
make run_coverage

Build

make build

Contributing

1. Fork it (https://github.com/your-github-user/fred/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Pim Snel - creator and maintainer