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

const isBinaryFile = require("isbinaryfile").isBinaryFile;

const data = await fs.readFile("some_file");
const stat = await fs.lstat("some_file");

isBinaryFile(data, stat.size).then((result) => {
  if (result) {
    console.log("It is binary!")
  }
  else {
    console.log("No it is not.")
  }
}));

let bytes = fs.readFileSync(("some_file"));
let size = fs.lstatSync(("some_file").size;
isBinaryFile.sync(bytes, size); // true or false

Testing

Run npm install, then run npm test.