正则表达式：匹配从A开始直到但不包括B的所有内容

Question

I have a file with an input similar to this:

CQUAD4 123123 123 234
CQUAD4 123123 123 234
CQUAD4 123123 123 234
PCOMP 123 123 123 123
123 123 123 123 123
123 123 1231 23
CQUAD4 123123 123 234
CQUAD4 123123 123 234
CQUAD4 123123 123 234
CQUAD4 123123 123 234
CQUAD4 123123 123 234
PCOMP 123 123 123 123
123 123 123 123 123
123 123 1231 23
432 234 2342 34
CQUAD4 123123 123 234
CQUAD4 123123 123 234
CQUAD4 123123 123 234
CQUAD4 123123 123 234

I want to capture

PCOMP 123 123 123 123
123 123 123 123 123
123 123 1231 23

and

PCOMP 123 123 123 123
123 123 123 123 123
123 123 1231 23
432 234 2342 34

I currently have PCOMP((.|\\n)*)CQUAD4 but it captures everything, including the CQUAD4 block in between. What should I use in order to match starting from PCOMP , up until the character before the next instance of CQUAD4 ? Thanks in advance.

Answer 1

You might get along with

PCOMP[\s\S]*?(?=CQUAD)

See a demo on regex101.com .
(.|\\n) is one of the most inefficient patterns you can think of, really.

Answer 2

Use the *? quantifier to lazily match the inside part:

PCOMP((.|\n)*?)CQUAD4

By default, * is greedy, and will find the biggest match possible.