SC1104

Use #!, not just !, for the shebang.

Problematic code:

!/bin/sh
echo "Hello"

Correct code:

#!/bin/sh
echo "Hello"

Rationale:

You appear to be specifying an interpreter in a shebang, but it's missing the hash part. The shebang must always start with #!.

Even the name "shebang" itself comes from "hash" (#) + "bang" (!).

Exceptions:

None.