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, CSV, and KDL.

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

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Features

• Multi-format support: JSON, YAML, TOML, XML, CSV, HCL, INI, KDL.
• 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.

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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.

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Shell Completion

Dasel supports tab-completion for Bash, Zsh, Fish, and PowerShell. Generate and load the completion script for your shell:

# Bash
source <(dasel completion bash)

# Zsh
source <(dasel completion zsh)

# Fish
dasel completion fish | source

# PowerShell
dasel completion powershell | Out-String | Invoke-Expression

See the shell completion docs for permanent installation instructions.

Man Page

Generate and view the man page:

dasel man | man -l -

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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"
    }
]

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Documentation

Full documentation is available at daseldocs.tomwright.me.

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Contributing

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

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License

MIT License. See LICENSE for details.

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