dt-cli-tools

View, filter, and diff tabular data files from the command line

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dtcat · dtfilter · dtdiff · Install · Claude Code

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Three read-only binaries, no runtime dependencies. Supports CSV, TSV, Parquet, Arrow/Feather, JSON, NDJSON, and Excel.

# View a file
dtcat data.parquet

# Filter rows
dtfilter data.csv --filter "Amount>1000" --sort "Amount:desc"

# Diff two files
dtdiff old.csv new.csv --key ID

Supersedes xl-cli-tools — same filtering and diff capabilities, now for all tabular formats.

Supported Formats

Format	Extensions	Detection
CSV	.csv	delimiter heuristic
TSV	.tsv, .tab	delimiter heuristic
Parquet	.parquet, .pq	PAR1 magic
Arrow/Feather	.arrow, .feather, .ipc	ARROW1 magic
JSON	.json	[ prefix
NDJSON	.ndjson, .jsonl	{ prefix
Excel	.xlsx, .xls, .xlsb, .ods	ZIP/OLE magic

Format detection: --format flag > magic bytes > file extension. CSV delimiter auto-detected (comma, tab, semicolon).

Installation

Pre-built binaries (macOS)

Download from Releases:

# Apple Silicon (macOS)
for tool in dtcat dtfilter dtdiff; do
  curl -L "https://github.com/LouLouLibs/dt-cli-tools/releases/latest/download/${tool}-aarch64-apple-darwin" \
    -o ~/.local/bin/$tool
done
chmod +x ~/.local/bin/dt{cat,filter,diff}

# Intel Mac (macOS)
for tool in dtcat dtfilter dtdiff; do
  curl -L "https://github.com/LouLouLibs/dt-cli-tools/releases/latest/download/${tool}-x86_64-apple-darwin" \
    -o ~/.local/bin/$tool
done
chmod +x ~/.local/bin/dt{cat,filter,diff}

From source

cargo install --path .

Requires Rust 1.85+.

dtcat — View Data Files

# Overview: schema + data (<=50 rows all, >50 head/tail 25)
dtcat data.parquet

# Column names and types only
dtcat data.csv --schema

# Summary statistics (count, mean, std, min, max, median)
dtcat data.csv --describe

# File metadata (size, format, sheets)
dtcat report.xlsx --info

# Pick a sheet in a multi-sheet workbook
dtcat report.xlsx --sheet Revenue

# First 10 rows / last 5 rows
dtcat data.csv --head 10
dtcat data.csv --tail 5

# CSV output for piping
dtcat data.parquet --csv

# Random sample of rows
dtcat huge.parquet --sample 20
dtcat huge.parquet --sample 50 --csv

# Convert between formats
dtcat data.csv --convert parquet -o data.parquet
dtcat report.xlsx --sheet Revenue --convert csv -o revenue.csv
dtcat data.parquet --convert ndjson              # text formats go to stdout

# Override format detection
dtcat data.txt --format csv

# Skip metadata rows above header
dtcat data.csv --skip 2

Example output

# File: sales.parquet (245 KB)
# Format: Parquet

## Data (1240 rows x 4 cols)

| Column  | Type   |
|---------|--------|
| date    | Date   |
| region  | String |
| amount  | Float  |
| units   | Int    |

| date       | region | amount  | units |
|------------|--------|---------|-------|
| 2024-01-01 | East   | 1234.56 | 100   |
| 2024-01-02 | West   | 987.00  | 75    |
... (1190 rows omitted) ...
| 2024-12-30 | East   | 1100.00 | 92    |
| 2024-12-31 | West   | 1250.75 | 110   |

Adaptive defaults

• Single sheet/file, <=50 rows: shows all data
• Single sheet/file, >50 rows: first 25 + last 25 rows
• Multiple sheets: lists schemas, pick one with --sheet

Modes --schema, --describe, --info, and data (default) are mutually exclusive.

--sample N randomly selects N rows; mutually exclusive with --head/--tail/--all.

--convert FORMAT writes to a different format. Use -o PATH for output file (required for binary formats Parquet/Arrow; optional for text formats which default to stdout). Supported targets: csv, tsv, parquet, arrow, json, ndjson.

dtfilter — Query and Filter

# Filter rows by value
dtfilter data.csv --filter State=CA

# Numeric comparisons
dtfilter data.csv --filter Amount>1000

# Multiple filters (AND)
dtfilter data.csv --filter State=CA --filter Amount>1000

# Contains filter (case-insensitive)
dtfilter data.csv --filter Name~john

# Select columns
dtfilter data.csv --columns State,City,Amount

# Sort results
dtfilter data.csv --sort Amount:desc

# Limit output
dtfilter data.csv --sort Amount:desc --limit 10

# Window before filter
dtfilter data.csv --head 100 --filter State=CA

# CSV output for piping
dtfilter data.parquet --filter value>0 --csv

Filter operators

Operator	Meaning	Example
=	Equals	State=CA
!=	Not equals	Status!=Draft
>	Greater than	Amount>1000
<	Less than	Year<2024
>=	Greater or equal	Score>=90
<=	Less or equal	Price<=50
~	Contains (case-insensitive)	Name~john
!~	Not contains	Name!~test

--head/--tail apply before filtering. --limit applies after. Row count is printed to stderr.

dtdiff — Compare Two Files

# Positional diff (whole-row comparison)
dtdiff old.csv new.csv

# Key-based diff (match rows by ID, compare cell by cell)
dtdiff old.csv new.csv --key ID

# Composite key
dtdiff old.csv new.csv --key Date,Ticker

# Float tolerance (differences <= 0.01 treated as equal)
dtdiff old.csv new.csv --key ID --tolerance 0.01

# Only compare specific columns
dtdiff old.csv new.csv --key ID --columns Name,Salary

# Excel sheets
dtdiff report.xlsx other.xlsx --sheet Revenue

# Output formats
dtdiff old.csv new.csv --key ID --json
dtdiff old.csv new.csv --key ID --csv
dtdiff old.csv new.csv --no-color

Example output

--- old.csv
+++ new.csv

Added: 1 | Removed: 1 | Modified: 2

- ID: "3"  Name: "Charlie"  Department: "Engineering"  Salary: "88000"
+ ID: "5"  Name: "Eve"  Department: "Marketing"  Salary: "70000"
~ ID: "1"
    Salary: "95000" → "98000"
~ ID: "2"
    Department: "Marketing" → "Design"
    Salary: "72000" → "75000"

Diff modes

Positional (no --key): Every column defines row identity. Reports added/removed rows only.

Key-based (--key): Match rows by key columns, compare remaining columns cell by cell. Reports added, removed, and modified rows with per-cell changes. Supports composite keys, duplicate key detection, and float tolerance.

Exit codes (diff convention)

Code	Meaning
0	No differences
1	Differences found
2	Error

Claude Code integration

Claude Code skills are available in claude-skills. Claude can view data files, analyze schemas, filter rows, and compare files in conversations.

Exit codes

Tool	0	1	2
dtcat	success	runtime error	invalid arguments
dtfilter	success	runtime error	invalid arguments
dtdiff	no differences	differences found	error

License

MIT