It should be really straightforward to do. You're almost describing a quine. Try running spiraling quine for one (not-so-obvious) approach. My own quine is the Pentominos Solving Quine.

One common method that quines in Perl often use is to rewind the DATA handle or the 0 handle, which can read the script's own source code as data. If you want it to invoke the new version, see the exec() built-in function.

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