About

The null character (also known as null terminator) 1), abbreviated NUL, is a control character with the value zero

Position

It's the first character of most of the character set such as ASCII and unicode

You can get it with the 0 code point.

Example in Javascript:

String.fromCodePoint(o);

The null character may be used to determine an header position in a file.

Ie all previous characters may be part of an header that adds extra metadata information.

For instance 2), git will add:

  • the type of object
  • a space
  • the size in bytes of the content
  • and a final null byte.
header = "blob #{content.bytesize}\0"