Exetending your requirements a little, there is a neat feature that is useful when replacing tokens, like your HEADER and REMARK. You can execute code from within a substitute statement, for example:
$line =~ s/(HEADER|REMARK)/mysub($1)/ge;

[download]
That will call user-written subroutine mysub every time HEADER and REMARK are found in the text. The argument passed is the text matched inside (). Whatever is returned by mysub will replace the token. It probably would not be worth it for the simple substitution you mentioned, but for more complex combinations it can be very powerful.

In reply to Re: Newbie: uses/limits of perl in editing files by cdarke
in thread Newbie: uses/limits of perl in editing files by wherethewild

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.