A hash and exclamation mark naming the interpreter for a script.
Also known as: Hashbang, Interpreter directive
The two characters #! at the very start of a file tell the operating system which interpreter should run what follows. They must be the first two bytes of the file to have any effect.
Read by the kernel when a file is executed: the path following the two characters names the interpreter that receives the file.
Contexts: Software
Must occupy the first two bytes of the file. A blank line or a comment before it makes it ordinary text and the file will not run as intended.
Contexts: Software
A grid of two horizontal and two vertical strokes, immediately followed by an upright stroke with a dot beneath it.
The shebang begins with the same character that marks a comment, which is exactly why it is invisible to the shell itself.