in reply to reading file
Questions like this come up fairly often. In recent memory (actually I had to search for it, my recent memory isn't what it once was) is How best to strip text from a file?, more relevant to you is the sub question and corresponding answer, which seems like it'll do exactly what you need with minor modification.
"Please also give some basic and advance links to tutorials of regular expression."
perlretut along with Pattern Matching, Regular Expressions, and Parsing from the tutorials section.