Help need regex pattern

Question

(any symbol) _ (any symbol) _ (any symbol)

need as much as possible short regex patterns to extract symbols sequence between _, for ex:

abc123_abc12345ABC_123abc regex should extract - abc12345ABC

Answer 1

This would do it:

^[^_]+_([^_]+)_[^_]+$

The middle capture group would grab the middle string of characters.

Answer 2

([^_]*)_([^_]*)_([^_]*)

Answer 3

How about

^.*?_(.*?)_.*$

Answer 4

With (any symbol) do you really mean any symbol? Can it contain newlines? Can it contain underscores?

For now, I'll give this short regex:

_(.+)_