dasel

Dasel (short for data-selector) allows you to query and modify data structures using selector strings.

Comparable to jq / yq, but supports JSON, YAML, TOML, XML and CSV with zero runtime dependencies.

One tool to rule them all

Say good bye to learning new tools just to work with a different data format.

Dasel uses a standard selector syntax no matter the data format. This means that once you learn how to use dasel you immediately have the ability to query/modify any of the supported data types without any additional tools or effort.

Commands executed in the demo

# Piping data into dasel
echo '{"demo": "Integrating with github releases..."}' | dasel -r json 'demo'

# Fetch dasel releases from github api
curl -L \
    -H "Accept: application/vnd.github+json" \
    -H "X-GitHub-Api-Version: 2022-11-28" \
    https://api.github.com/repos/TomWright/dasel/releases > releases.json
less releases.json

# Extract and structure release data by version with download URL's by asset name
dasel -f releases.json -w yaml 'all().mapOf(version,tag_name,download,assets.all().mapOf(name,name,url,browser_download_url).merge()).merge()' > releases_download.yaml
less releases_download.yaml

# Restructure the above data into CSV format, destructuring into rows.
dasel -f releases_download.yaml -w csv 'all().download.all().mapOf(version,parent(2).version,name,name,url,url).merge()' > releases_download.csv
less releases_download.csv

# Fetch the first CSV row and output as JSON
dasel -f releases_download.csv -w json 'first()'

Table of contents

• Dasel
• One tool to rule them all
• Quickstart
• Completion
• Issue vs discussion
• Features
• Table of contents
• Documentation
• Playground
• Benchmarks
• Pre-Commit

Quickstart

Dasel is available on homebrew, ASDF, scoop, docker, Nix or as compiled binaries from the latest release.

brew install dasel

You can also install a development version with:

go install github.com/tomwright/dasel/v2/cmd/dasel@master

For more information see the installation documentation.

Select

echo '{"name": "Tom"}' | dasel -r json 'name'
"Tom"

See select documentation.

Convert json to yaml

echo '{"name": "Tom"}' | dasel -r json -w yaml
name: Tom

See select documentation.

Put

echo '{"name": "Tom"}' | dasel put -r json -t string -v 'contact@tomwright.me' 'email'
{
  "email": "contact@tomwright.me",
  "name": "Tom"
}

See put documentation.

Delete

echo '{
  "email": "contact@tomwright.me",
  "name": "Tom"
}' | dasel delete -r json '.email'
{
  "name": "Tom"
}

See delete documentation.

Completion

If you want to use completion from the terminal you can do the following (using zsh in this example):

Add the following to ~/.zshrc and reload your terminal.

export fpath=(~/zsh/site-functions $fpath)
mkdir -p ~/zsh/site-functions
dasel completion zsh > ~/zsh/site-functions/_dasel
compinit

Pre-Commit

Add dasel hooks to .pre-commit-config.yaml file

- repo: https://github.com/TomWright/dasel
  rev: v1.25.1
  hooks:
    - id: dasel-validate

for a native execution of dasel, or use:

• dasel-validate-docker pre-commit hook for executing dasel using the official Docker images
• dasel-validate-bin pre-commit hook for executing dasel using the official binary

Issue vs Discussion

I have enabled discussions on this repository.

I am aware there may be some confusion when deciding where you should communicate when reporting issues, asking questions or raising feature requests so this section aims to help us align on that.

Please raise an issue if:

• You find a bug.
• You have a feature request and can clearly describe your request.

Please open a discussion if:

• You have a question.
• You're not sure how to achieve something with dasel.
• You have an idea but don't quite know how you would like it to work.
• You have achieved something cool with dasel and want to show it off.
• Anything else!

Features

• Query/select data from structured data files.
• Update data in structured data files.
• Create data files.
• Supports multiple data formats/types.
• Convert between data formats/types.
• Uses a standard query/selector syntax across all data formats.
• Zero runtime dependencies.
• Available on Linux, Mac and Windows.
• Available to import and use in your own projects.
• Run via Docker.
• Faster than jq/yq.
• Pre-commit hooks.

Documentation

The official dasel docs can be found at daseldocs.tomwright.me.

Playground

You can test out dasel commands using the playground.

Source code for the playground can be found at github.com/TomWright/daselplayground.

Benchmarks

In my tests dasel has been up to 3x faster than jq and 15x faster than yq.

See the benchmark directory.

Stargazers over time