Regular Expressions 101

Explanation
Pro

Group 1(start((?!start).)*?end)

startthe literal text start (case sensitive)

Group 2((?!start).)*?

*?repeats the group contents below any number of times:

Negative Lookahead(?!start)

startthe literal text start (case sensitive)

.any Unicode character

endthe literal text end (case sensitive)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

s modifier: single line. Allows a dot to match line terminators

Detailed match information will be displayed here automatically.

25 tokens

(start((?!start).)*?end)

New

start spam
start rubbish
start wait for it...
    profit!
here end
start garbage
start second match
win. end

start spam
start rubbish
start wait for it...
    profit!
here end
start garbage
start second match
win. end