isBinaryFile

Detects if a file is binary in Node.js using ✨promises✨. Similar to Perl's `-B` switch, in that:

- it reads the first few thousand bytes of a file
- checks for a `null` byte; if it's found, it's binary
- flags non-ASCII characters. After a certain number of "weird" characters, the file is flagged as binary

Much of the logic is pretty much ported from ag.

Note: if the file doesn't exist or is a directory, an error is thrown.

# Installation

npm install isbinaryfile

# Usage

Returns `Promise<boolean>` (or just `boolean` for `*Sync`). `true` if the file is binary, `false` otherwise.

## isBinaryFile(filepath)

- `filepath` - a `string` indicating the path to the file.

## isBinaryFile(bytes[, size])

- `bytes` - a `Buffer` of the file's contents.
- `size` - an optional `number` indicating the file size.

## isBinaryFileSync(filepath)

- `filepath` - a `string` indicating the path to the file.

## isBinaryFileSync(bytes[, size])

- `bytes` - a `Buffer` of the file's contents.
- `size` - an optional `number` indicating the file size.

## Examples

Here's an arbitrary usage:

const isBinaryFile = require("isbinaryfile").isBinaryFile;
const fs = require("fs");
const filename = "fixtures/pdf.pdf";
const data = fs.readFileSync(filename);
const stat = fs.lstatSync(filename);
isBinaryFile(data, stat.size).then((result) => {
if (result) {
console.log("It is binary!")
}
else {
console.log("No it is not.")
}
});
const isBinaryFileSync = require("isbinaryfile").isBinaryFileSync;
const bytes = fs.readFileSync(filename);
const size = fs.lstatSync(filename).size;
console.log(isBinaryFileSync(bytes, size)); // true or false

# Testing

Run `npm install`, then run `npm test`.