You want the regex to match across multiple lines, so you will need to use /m so that ^ will match at the start of any line in the string, and /s so that . will match newlines. Ie. try: 

if(/^HEADER(.*?)GENRE_BY(.*)/sm) {
  print;
}

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In reply to Re: Question on RE based matching by BrowserUk
in thread Question on RE based matching by noobee

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