Reading and writing after a specific point in multilined text file

[reinhold]

Hi,

I need help to write a code which has to read and write numerical values from a text file before semicolon sign.

The textfile has multiple lines and goes like this:

option1 56;
option2 721;
option3 -1;
option4 0;

It should not read and write anything before the space and after the semicolon, only the numbers. Numbers can be negative or up to 3 digits.