truncate-utf8-bytes

What is truncate-utf8-bytes?

The 'truncate-utf8-bytes' npm package is designed to truncate a string to a specified number of bytes, ensuring that the resulting string is valid UTF-8. This is particularly useful when dealing with systems that have byte-length constraints for strings, such as databases or network protocols.

What are truncate-utf8-bytes's main functionalities?

Truncate a string to a specified number of bytes

This feature allows you to truncate a string to a specified number of bytes. In this example, the string 'Hello, world!' is truncated to 5 bytes, resulting in 'Hello'.

const truncate = require('truncate-utf8-bytes');
const str = 'Hello, world!';
const truncatedStr = truncate(str, 5);
console.log(truncatedStr); // Output: 'Hello'

Handle multi-byte characters correctly

This feature ensures that multi-byte characters are handled correctly. In this example, the Japanese string 'こんにちは' is truncated to 6 bytes, resulting in 'こん', which is a valid UTF-8 string.

const truncate = require('truncate-utf8-bytes');
const str = 'こんにちは'; // 'Hello' in Japanese
const truncatedStr = truncate(str, 6);
console.log(truncatedStr); // Output: 'こん'

Other packages similar to truncate-utf8-bytes

utf8-byte-length

The 'utf8-byte-length' package calculates the byte length of a UTF-8 string but does not provide truncation functionality. It is useful for determining the byte length of a string before performing operations that require byte-length constraints.

utf8

The 'utf8' package provides utilities for encoding and decoding UTF-8 strings but does not include truncation functionality. It is more focused on converting between UTF-8 and other encodings.

string-byte-length

The 'string-byte-length' package calculates the byte length of a string and can also truncate it to a specified byte length. However, it may not handle multi-byte characters as gracefully as 'truncate-utf8-bytes'.

README

truncate-utf8-bytes

Truncate a string to the given length in bytes. Correctly handles multi-byte characters and surrogate pairs.

A browser implementation that doesn't use Buffer.byteLength is provided to minimize build size.

Example

var truncate = require("truncate-utf8-bytes")
var str = "a☃" // a = 1 byte, ☃ = 3 bytes
console.log(truncate(str, 2))
// -> "a"

API

var truncate = require("truncate-utf8-bytes")

When using browserify or webpack, this automatically resolves to an implementation that does not use Buffer.byteLength.

truncate(string, length)

Returns string truncated to at most length bytes in length.