Hi,
  I got same situation but i can't use awk program. I can only use SED command.
    Is it possible to filter rows with sed command

temp.txt
1;a;200
2;b;300
3;a;400
4;c;800
5;b;900

Now i want to filter on second field if field is equal to "a" or "b" then display rows otherwise throw it.

is it doable?