Underscore CLI - Text Processing with Lodash Syntax - tools Cheatsheets

Command-line Utility for Text Processing with Lodash-Style Syntax

Underscore CLI is a powerful command-line utility that allows developers to process text and data, particularly JSON, using familiar lodash-style syntax. This tool streamlines common data manipulation tasks directly from your terminal, making it an invaluable asset for scripting, automation, and quick data analysis.

Core Functionality and Usage Examples

The primary function of Underscore CLI is to apply lodash functions to input data, typically JSON. Below are several examples demonstrating its versatility:

Transforming JSON Input

You can transform JSON input by selecting and mapping properties. This is useful for extracting specific data points or restructuring JSON objects.

# Transform JSON input using lodash-style syntax
underscore select 'map(array, "property")' < input.json

Filtering JSON Arrays

Underscore CLI excels at filtering JSON arrays based on specific criteria, allowing you to isolate relevant data.

# Apply lodash functions on a JSON array
underscore select 'filter(array, { "active": true })' < input.json

Sorting JSON Data

Easily sort JSON arrays by a particular property value, which is crucial for ordered data presentation.

# Sorting a JSON array by a property value
underscore select 'sortBy(array, "age")' < input.json

Picking Specific Properties

Select only the desired properties from objects within a JSON array, simplifying complex data structures.

# Pick specific properties from objects in a JSON array
underscore select 'map(array, pick(["name", "age"]))' < input.json

Summarizing and Aggregating Data

Perform aggregations like summing values across a JSON array using the reduce function.

# Summarize values in a JSON array
underscore select 'reduce(array, (sum, n) => sum + n.value, 0)' < input.json

Grouping Elements

Group elements of a JSON array based on a common property, creating categorized datasets.

# Group elements of a JSON array by a property
underscore select 'groupBy(array, "category")' < input.json

Counting Elements Conditionally

Count elements within a collection based on a specified condition, providing valuable statistical insights.

# Count elements in a collection based on a condition
underscore select 'countBy(array, item => item.completed ? "completed" : "pending")' < input.json

Plucking Properties

Extract a single property from each object in a JSON array to create a simple list of values.

# Pluck a single property from each object in a JSON array
underscore select 'pluck(array, "name")' < input.json

Finding Specific Objects

Locate a specific object within a JSON array that matches a given condition.

# Find an object in a JSON array based on a condition
underscore select 'find(array, { "id": 1 })' < input.json

Removing Falsy Values

Clean up arrays by removing falsy values (e.g., null, undefined, false, 0, "").

# Remove falsy values from a JSON array
underscore select 'compact(array)' < input.json

Further Resources

For more advanced usage and a deeper understanding of lodash functions, refer to the official lodash documentation: