is-binary-file-simple

Check with minimal effort if a file is binary, e.g. before trying to apply text file methods

Does not conflict with non-English character encodings, see Demo with Hebrew text.

hh lohmann <[email protected]>

Caution

For being fast and simple, the file is not fully analyzed (see Details), but sufficently enough for every day files. It is not a tool against malicious files hiding executable code in seemingly harmless text files and of course not a validator for potentially malformed files.

Synopsis

  import { isBinaryFileSimple } from 'is-binary-file-simple'

  isBinaryFileSimple( file )

Parameters

file

File to check (filename with or without path)

Returns

true if given file is a binary file, false else

Examples

  const getFirstLine = async function( file ){
    if( isBinaryFileSimple( file ) ){
      console.log( 'Binary files cannot be read by line' );
    }
    else{
      // ... code ...
      console.log( `First line of ${ file }:\n${ firstLine }` );
    }
  }
  getFirstLine( 'README.md' );

Demo

See demos on GitHub Pages for this repo

Installation

Pick for your preferred package manager:

  npm i is-binary-file-simple

  pnpm i is-binary-file-simple

  bun i is-binary-file-simple

  # For Yarn you should double check docs for your and / or
  # current Yarn version, newer versions do not treat `i package_name`
  # as an alias for `add ...` and exclude global installations
  yarn add is-binary-file-simple

Details

• The first 256 Bytes of the given file are checked for containing Control Characters. If Control Characters (execpt LF (Line Feed) and CR (Carriage Return) for line breaks) exist, the file is binary.

• For PDFs the magic signature is checked

Tests

• Code tests to be run with Node.js / Bun available in Source Code

Source Code

• GitHub: https://github.com/hh-lohmann/is-binary-file-simple

License

• MIT (see LICENSE.txt)

References

RFC 20: ASCII format for network interchange: Control Characters

• https://datatracker.ietf.org/doc/html/rfc20#section-5.2

Wikipedia: List of file signatures

• NB: File signatures are often called "magic number / pattern / bytes"
• https://en.wikipedia.org/wiki/List_of_file_signatures