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I am new to regular expression and trying to find out what this means.
(?:(?:^KC[\\x00-\\xff]{50}))
Upon looking up online, ?: means no backtrace, I am not sure what that means?
Also from ^ , does that mean a line that does not contain “KC….” for 50 character long?
When you use brackets
()in regex, you can use references (\1..\9) to captured groups further in the regex. Example:(a|b)_\1will match'a_a'and'b_b'.?:means that the captured group won’t have a number (actually, it’s better to say that it won’t be captured, it’s just a group).^means negation in character classes (in[]). Outside[]it means beginning of the line.