Csvnorm

Command line tool to normalize CSV and *SV files.

Steps:

• Convert to UTF-8 encoding
• Replace separator with ,
• Reformat
  • Date columns to ISO8601
  • Number columns to 1456.25
  • Currency columns to 1539.16 $

Encoding Detection

The input encoding is detected in this order:

1. Byte Order Mark (BOM) — UTF-8, UTF-16 LE/BE, and UTF-32 LE/BE BOMs are recognized and stripped from the output.
2. UTF-16 heuristic — Files without a BOM are identified by the alternating zero-byte pattern of ASCII text encoded as UTF-16 LE or BE.
3. Strict UTF-8 validation — The byte stream is checked against the UTF-8 grammar (rejecting overlong sequences and surrogate halves).
4. chardet fallback — Used to discriminate between single-byte encodings such as ISO-8859-x and windows-125x.
5. windows-1252 as the last resort if every previous step is inconclusive.

The detected encoding is shown in the interpretation summary when the output is a terminal, and can be overridden via --encoding.

CLI Version

Installation

npm install --global csvnorm

Usage

Usage:
  csvnorm [Options] INFILE [> OUTFILE]
  csvnorm [Options] < INFILE [> OUTFILE]

Options:
  --date-format   Specify an additional prioritized input date format   [string]
  --encoding      Overwrite detected input encoding                     [string]
  --in-place      Normalize CSV file in place         [boolean] [default: false]
  --iso-datetime  Output datetimes with format YYYY-MM-DD[T]HH:mm:ss.SSS[Z]
                                                      [boolean] [default: false]
  --skip-start    Skip lines at the start of the input     [number] [default: 0]
  --skip-end      Skip lines at the end of the input       [number] [default: 0]
  --version       Show version number                                  [boolean]
  --help          Show help                                            [boolean]

Examples:
  csvnorm input.csv > normalized.csv        Normalize a CSV file
  cat input.csv | csvnorm > normalized.csv  Pipe and normalize a CSV file
  csvnorm --date-format "dd/mm/yyyy" i.csv  Normalize a CSV file with an unusual
                                            date format

Node Module

Installation

npm install --save csvnorm

csvnorm is an ES module and requires Node.js 20 or later.

Usage

With files:

import csvnorm from "csvnorm"

csvnorm({
  filePath: csvFilePath,
  inPlace: true,
})

With streams:

import csvnorm from "csvnorm"

csvnorm({
  readableStream: process.stdin,
  writableStream: process.stdout,
})

Warning: Numbers from 1,000 to 999,999 with 3 decimal places are parsed as floats (1.000 to 999.999). Only numbers larger than 1,000,000 or numbers with less or more than 3 decimal places can be unambiguously parsed as integers (1000000).