add-bom

A simple command-line utility to add a UTF-8 BOM (Byte Order Mark) to files. This is particularly useful for CSV files that need to be opened correctly in Excel on macOS, where files without a BOM might be interpreted with incorrect character encoding.

Installation

The recommended way to install this tool is using pipx:

pipx install add-bom

Usage

add-bom <file>

Options

• --force: Force add BOM to file regardless of current encoding

Examples

Add BOM to a UTF-8 CSV file:

add-bom data.csv

Force add BOM to a file (use with caution):

add-bom data.csv --force

What is a BOM?

A BOM (Byte Order Mark) is a special character sequence at the beginning of a text file that indicates the encoding of the file. For UTF-8 files, the BOM is the sequence EF BB BF in hexadecimal.

Why is this needed?

When opening CSV files in Excel on macOS, files without a BOM might be interpreted with incorrect character encoding (like MacRoman or Windows-1252), leading to garbled text. Adding a UTF-8 BOM ensures that Excel correctly recognizes the file as UTF-8 encoded.

Safety Features

The tool includes several safety checks:

• Verifies the file exists
• Checks if the file already has a BOM
• By default, only adds BOM to files that are already UTF-8 encoded
• Requires --force flag to add BOM to files with other encodings

License

MIT License - See LICENSE file for details