mdsh - Markdown shell pre-processor

the mdsh project describes a Markdown language extension that can be used to automate some common tasks. The goal is to keep the syntax compatible while allowing a pre-processor (mdsh) to be run against the file.

Quite often I find myself needing to embed a snippet of code or markdown from a different file. But GitHub doesn't allow loading other files, even when selecting a format that supports it (like AsciiDoc).

Another quite common use-case is to embed the output of a command as a fenced code block or markdown content. For example the project is a CLI and the --help output could be displayed in the README.md.

Both of these cases are supported by extending the existing syntax and running mdsh against the file.

Usage

$ mdsh --help

mdsh 0.1.3
zimbatm <zimbatm@zimbatm.com>
Markdown shell pre-processor

USAGE:
    mdsh [FLAGS] [OPTIONS] [INPUT]

FLAGS:
        --clean      Only clean the file from blocks
    -h, --help       Prints help information
    -V, --version    Prints version information

OPTIONS:
    -o, --output <OUTPUT>    Path to the output file, defaults to the input value
        --work_dir <DIR>     Directory to execute the scripts under, defaults to the input folder

ARGS:
    <INPUT>    Path to the markdown file [default: README.md]

Syntax Extensions

Inline Shell Code

Syntax regexp:

^`[$>] ([^`]+)`\s*$

Inline Shell Code are normal inline code that:

start at the beginning of a line
include either $ or > at the beginning of their content
contain a shell command

When those are enountered, the command is executed by mdsh and output as either a fenced code block ($) or markdown code (>).

$ runs the command and outputs a code block
> runs the command and outputs markdown

Examples:

`$ date`
```
Mon Feb 18 22:47:07 CET 2019
```

`> nix-info --markdown`
<!-- BEGIN mdsh -->
 - system: `"x86_64-linux"`
 - host os: `Linux 4.20.7, NixOS, 19.03.git.d62d4bc3864M (Koi)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.2`
 - channels(root): `""`
 - channels(zimbatm): `""`
 - nixpkgs: `/home/zimbatm/go/src/github.com/nixos/nixpkgs-zimbatm`

<!-- END mdsh -->

Link Includes

Syntax regexp:

^\[[$>] ([^\]]+)]\([^\)]+\)\s*$

Link Includes work similarily to code blocks but with the link syntax.

$ loads the file and embeds it as a code block
> loads the file and embeds it as markdown

Examples:

[$ code.rb](code.rb)
```
require "pp"

pp ({ foo: 3 })
```

[> example.md](example.md)
<!-- BEGIN mdsh -->
*this is part of the example.md file*
<!-- END mdsh -->

Installation

The best way to install mdsh is with the rust tool cargo.

cargo install mdsh

If you are lucky enough to be a nix user:

nix-env -f https://github.com/NixOS/nixpkgs/archive/master.tar.gz -iA mdsh

Known issues

The tool currently lacks in precision as it doesn't parse the Markdown file, it just looks for the desired blocks by regexp. It means that in some cases it might misintepret some of the commands. Most existing Markdown parsers are used to generate HTML in the end and are thus not position-preserving. Eg: pulldown-cmark

The block removal algorithm doesn't support output that contains triple backtick or .

User Feedback

Issues

If you have any problems with or questions about this project, please contact use through a GitHub issue.

Contributing

You are invited to contribute new features, fixes or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.

License

> LICENSE

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.