I need to crop all text between one expression(let it be expr1) and the
first match of another(expr2). The text looks like:
 some text expr1 some text expr2 some text expr2.       I know nothing
about length of the text.
The point is that i can't just write expr1(.*)expr2, because the expr2 is
repeated more than one time (and it crops everything before the last match
of expr2 ), but I need the text just before the first match of expr2. Maybe
I can say that "some text" must not contain expr2, but i don't know how to
do this. Help me please.

Thank you in advance.