Big Chef

A Go-based tool for modifying XML, JSON, and text documents using XPath/JSONPath/Regex expressions and Lua transformations.

Features

• Multi-Format Processing:
  • XML (XPath)
  • JSON (JSONPath)
  • Text (Regex)
• Node Value Modification: Update text values in XML elements, JSON properties or text matches
• Attribute Manipulation: Modify XML attributes, JSON object keys or regex capture groups
• Conditional Logic: Apply transformations based on document content
• Complex Operations:
  • Mathematical calculations
  • String manipulations
  • Date conversions
  • Structural changes
  • CSV/TSV parsing with comments and headers
  • Whole ass Lua environment
• Error Handling: Comprehensive error detection for:
  • Invalid XML/JSON
  • Malformed XPath/JSONPath
  • Lua syntax errors

Usage Examples

1. Basic field modification

<!-- Input -->
<price>44.95</price>

<!-- Command -->
chef -xml "//price" "v=v*2" input.xml

<!-- Output -->
<price>89.9</price>

2. Supports glob patterns

chef -xml "//price" "v=v*2" data/**.xml

3. Attribute Update

<!-- Input -->
<item price="10.50"/>

<!-- Command -->
chef -xml "//item/@price" "v=v*2" input.xml

<!-- Output --> 
<item price="21"/>

3. JSONPath Transformation

// Input
{
  "products": [
    {"name": "Widget", "price": 19.99},
    {"name": "Gadget", "price": 29.99}
  ]
}

// Command
chef -json "$.products[*].price" "v=v*0.75" input.json

// Output
{
  "products": [
    {"name": "Widget", "price": 14.99},
    {"name": "Gadget", "price": 22.49}
  ]
}

4. Regex Text Replacement

Regex works slightly differently, up to 12 match groups are provided as v1..v12 and s1..s12 for numbers and strings respectively. A special shorthand "!num" is also provided that simply expands to (\d*\.?\d+).

<!-- Input -->
<description>Price: $15.00 Special Offer</description>

<!-- Command -->
chef "Price: $!num Special Offer" "v1 = v1 * 0.92" input.xml

<!-- Output -->
<description>Price: $13.80 Special Offer</description>

5. Conditional Transformation

<!-- Input -->
<item stock="5" price="10.00"/>

<!-- Command -->
chef -xml "//item" "if tonumber(v.stock) > 0 then v.price = v.price * 0.8 end" input.xml

<!-- Output -->
<item stock="5" price="8.00"/>

6. CSV/TSV Processing

The Lua environment includes CSV parsing functions that support comments, headers, and custom delimiters.

-- Basic CSV parsing
local rows = fromCSV(csvText)

-- With options
local rows = fromCSV(csvText, {
    delimiter = "\t",        -- Tab delimiter for TSV (default: ",")
    hasHeaders = true,       -- First row is headers (default: false)
    hasComments = true       -- Filter lines starting with # (default: false)
})

-- Access by index
local value = rows[1][2]

-- Access by header name (when hasHeaders = true)
local value = rows[1].Name

-- Convert back to CSV
local csv = toCSV(rows, "\t")  -- Optional delimiter parameter

Example with commented TSV file:

-- Input file:
-- #mercenary_profiles
-- Id	Name	Value
-- 1	Test	100
-- 2	Test2	200

local csv = readFile("mercenaries.tsv")
local rows = fromCSV(csv, {
    delimiter = "\t",
    hasHeaders = true,
    hasComments = true
})

-- Access data
rows[1].Name  -- "Test"
rows[2].Value -- "200"

Lua Helper Functions

The Lua environment includes many helper functions:

Math Functions

• min(a, b), max(a, b) - Min/max of two numbers
• round(x, n) - Round to n decimal places
• floor(x), ceil(x) - Floor/ceiling functions

String Functions

• upper(s), lower(s) - Case conversion
• trim(s) - Remove leading/trailing whitespace
• format(s, ...) - String formatting
• strsplit(inputstr, sep) - Split string by separator

CSV Functions

• fromCSV(csv, options) - Parse CSV/TSV text into table of rows
  • Options: delimiter (default: ","), hasHeaders (default: false), hasComments (default: false)
• toCSV(rows, delimiter) - Convert table of rows back to CSV text

Conversion Functions

• num(str) - Convert string to number (returns 0 if invalid)
• str(num) - Convert number to string
• is_number(str) - Check if string is numeric

Table Functions

• isArray(t) - Check if table is a sequential array
• dump(table, depth) - Print table structure recursively

HTTP Functions

• fetch(url, options) - Make HTTP request, returns response table
  • Options: method, headers, body
  • Returns: {status, statusText, ok, body, headers}

Regex Functions

• re(pattern, input) - Apply regex pattern, returns table with matches

Installation

go build -o chef main.go

# Process XML file
./chef -xml "//price" "v=v*1.2" input.xml

# Process JSON file 
./chef -json "$.prices[*]" "v=v*0.9" input.json