johnkerl/miller

Health v2 · maintenance only

Flags: no_license

Adoption not part of the score

10003 stars · 240 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Miller (mlr) is a command-line tool like awk, sed, cut, join, and sort but designed for name-indexed data such as CSV, TSV, JSON, JSON Lines, and YAML. It supports querying, shaping, reformatting, sorting, and statistically aggregating tabular data with familiar verbs plus a built-in expression language.

Use cases

• convert csv files to json from the command line
• clean and reshape csv data before loading into a database
• sort and filter tsv files by named columns
• compute statistics like sums and counts over csv records
• pretty-print json lines data for inspection
• drop or rename columns in large csv files without opening a spreadsheet
• replace awk one-liners for name-indexed data

When to choose

• you work with CSV, TSV, JSON, or JSON Lines data in the terminal
• you want awk/sed-like power but with named-field awareness
• you need fast streaming processing of large tabular files
• you want format conversion between CSV, JSON, and YAML without writing code

When to avoid

• you need a full dataframe library with plotting and rich statistics
• your data is deeply nested binary formats like Parquet or Avro
• you prefer interactive GUI or notebook-based data exploration

Facets

cli-tool · maturity stable

cli etl data-science parser developer-tools data-science developer-tools files windows cli cross-platform csv tsv json json-lines awk-alternative data-wrangling format-conversion unix-tools statistics streaming data-engineering command-line linux macos

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