title: Subdivide a variable by byte length
body: <p>I have a byte-only variable (generated by openssl_random_pseudo_bytes) and I need to get the first 5 bytes.</p>
  <p>I would like to know if this is possible in PHP and, if so, which function should I use?</p>
  <p>If you can also provide an example it is appreciated but not required.</p>
  <p>Thanks, Have a nice day!</p>