dasel

Query a value from a JSON file

$ dasel -f [file.json] '[selector]'

$ dasel -f [config.yaml] '.database.host'

$ dasel -f [input.json] -p json -w yaml

$ dasel put -f [file.json] -v '[new_value]' '[selector]'

$ dasel delete -f [file.yaml] '[selector]'

$ cat [file.yaml] | dasel -p yaml -w json

$ dasel -f [file.xml] '.root.element'

dasel [command] [flags] [selector]
dasel select [-f file] [-p parser] [-w writer] selector
dasel put [-f file] [-t type] [-v value] selector
dasel delete [-f file] selector

dasel (Data Selector) is a command-line tool for querying and modifying structured data files. It provides a unified interface for working with JSON, YAML, TOML, XML, CSV, INI, and HCL formats using a consistent selector syntax.
The tool supports three main operations: select for querying data, put for modifying or adding values, and delete for removing keys. Selectors use dot notation for nested access (e.g., `.database.host`) and bracket notation for array indices (e.g., `.users.[0].name`).
Dasel can convert between formats by specifying different input and output parsers, making it useful for configuration file transformations. It reads from files or stdin and writes to files or stdout, integrating well with shell pipelines.

-f, --file PATH

Input file path; reads from stdin if omitted

Parser for input data (json, yaml, toml, xml, csv, ini, hcl); auto-detected from file extension

Output format; defaults to input parser type

Value type for put command (string, int, bool, json)

Value to set with put command

Output file path; writes to stdout if omitted

Alias for --parser

Pretty-print output for readability

Compact output without formatting

Select multiple values matching the selector

Output null values explicitly

Enable colored output

Escape HTML entities in output

Display help information

Display version information

Comments in YAML and TOML files are discarded when writing due to parser limitations. The entire document is loaded into memory, so very large files may cause high memory usage. Array indices are zero-based. When modifying files, the original formatting may not be preserved exactly.

Dasel was created by Tom Wright and first released in 2020. Written in Go, it was designed as a universal alternative to format-specific tools like jq (JSON), yq (YAML), and xmlstarlet (XML). The name is a portmanteau of "data" and "select". It gained popularity for its ability to use identical selector syntax across multiple data formats and its single-binary distribution with no dependencies.

jq(1), yq(1), xmlstarlet(1), mlr(1)