How to extract the first two characters of a string in shell scripting?

Question

For example, given:

USCAGoleta9311734.5021-120.1287855805

I want to extract just:

US

Answer 1

easiest way is

${string:position:length}

Where this extracts $length substring from $string at $position.

This is a bash builtin so awk or sed is not required.