Question

I need to read a file which is encoded with ISO-8859-1 (also called latin1), something like this:

var file_contents = fs.readFileSync("test_data.html", "latin1");

However, Node complains about “latin1” or “ISO-8859-1” not being a valid encoding (“Error: Unknown encoding”).

What encodings does readFileSync accept?

Answer 1

The list of encodings that node supports natively is rather short:

• ascii
• base64
• base64url (Node v14+)
• hex
• ucs2/ucs-2/utf16le/utf-16le
• utf8/utf-8
• binary/latin1 (ISO8859-1, latin1 only in node 6.4.0+)

If you are using an older version than 6.4.0, or don’t want to deal with non-Unicode encodings, you can recode the string:

Use iconv-lite to recode files:

var iconvlite = require('iconv-lite');
var fs = require('fs');

function readFileSync_encoding(filename, encoding) {
    var content = fs.readFileSync(filename);
    return iconvlite.decode(content, encoding);
}

Alternatively, use iconv:

var Iconv = require('iconv').Iconv;
var fs = require('fs');

function readFileSync_encoding(filename, encoding) {
    var content = fs.readFileSync(filename);
    var iconv = new Iconv(encoding, 'UTF-8');
    var buffer = iconv.convert(content);
    return buffer.toString('utf8');
}