dasel

Dasel

Dasel (short for Data-Select) is a command-line tool and library for querying, modifying, and transforming data structures such as JSON, YAML, TOML, XML, and CSV.

It provides a consistent, powerful syntax to traverse and update data — making it useful for developers, DevOps, and data wrangling tasks.

Features

• Multi-format support: JSON, YAML, TOML, XML, CSV, HCL (with more planned).
• Unified query syntax: Access data in any format with the same selectors.
• Query & search: Extract values, lists, or structures with intuitive syntax.
• Modify in place: Update, insert, or delete values directly in structured files.
• Convert between formats: Seamlessly transform data from JSON → YAML, TOML → JSON, etc.
• Script-friendly: Simple CLI integration for shell scripts and pipelines.
• Library support: Import and use in Go projects.

Installation

Homebrew (macOS/Linux)

brew install dasel

Go Install

go install github.com/tomwright/dasel/v3/cmd/dasel@master

Prebuilt Binaries

Prebuilt binaries are available on the Releases page for Linux, macOS, and Windows.

None of the above?

See the installation docs for more options.

Basic Usage

Selecting Values

By default, Dasel evaluates the final selector and prints the result.

echo '{"foo": {"bar": "baz"}}' | dasel -i json 'foo.bar'
# Output: "baz"

Modifying Values

Update values inline:

echo '{"foo": {"bar": "baz"}}' | dasel -i json 'foo.bar = "bong"'
# Output: "bong"

Use --root to output the full document after modification:

echo '{"foo": {"bar": "baz"}}' | dasel -i json --root 'foo.bar = "bong"'
# Output:
{
  "foo": {
    "bar": "bong"
  }
}

Update values based on previous value:

echo '[1,2,3,4,5]' | dasel -i json --root 'each($this = $this*2)'
# Output:
[
    2,
    4,
    6,
    8,
    10
]

Format Conversion

cat data.json | dasel -i json -o yaml

Recursive Descent (..)

Searches all nested objects and arrays for a matching key or index.

echo '{"foo": {"bar": "baz"}}' | dasel -i json '..bar'
# Output:
[
    "baz"
]

Search (search)

Finds all values matching a condition anywhere in the structure.

echo '{"foo": {"bar": "baz"}}' | dasel -i json 'search(bar == "baz")'
# Output:
[
    {
        "bar": "baz"
    }
]

Documentation

Full documentation is available at daseldocs.tomwright.me.

Contributing

Contributions are welcome! Please see the CONTRIBUTING.md for details.

License

MIT License. See LICENSE for details.

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