Several things, Rich. Thank you for being awesome; (a) helpful, (b) prompt reply, (c) not condescending or elitist. I have noticed a lot of really bad info on the internet, not because it is wrong, but because it tells and shows HOW to do a thing right, but explains nothing about the WHY of the HOW.
You are being a good teacher here, hence "moderator" status. Now, I have probably used the chmod command in ten or twenty other "recipes" and still don't know quite what it does. I have probably even read the man pages, but I think, if this works (I haven't tried it yet), I will forever remember "chmod" as "That instruction that makes a bash shell script, ".sh", executable". Now, the "777" is a bit more opaque and abstruse, and, quite frankly arbitrary? But I can't argue; I am a biologist, and our science probably looks crazy to you guys, and your science, too!
OK one last thing (that will probably make you pull your hair out, and whisper-muttering-yelling "NOOBIE!"), is Tannenbaum. Not, tis the season, "Oh Tannenbaum", but Arthur Tanenbaum, Minix, and Linux. I have been reading his Minix book, because I want to know about what Linus knew when he invented the stuff we are hacking away, diligently, daily, upon. And so, the file system structure (ambiguous terms here? yes. one meaning is e.g. minix, ext4, FAT, and another , meaning is the "Unix tree", or "directory structure"? I sometimes wish I was better with the distinctions and finer minutiae of "programmer-speak"?). So, I was thinking about directories and those "holdover", "standard-folders", from the standard UNIX type OSes, and how, I am a silly windows freak (until 2016), so I just make a folder, anywhere, when I want one. In theory, this is incorrect for Linux? Or perhaps, just a "cluttery" type attitude?
I read somewhere that certain of these "standard folders", in a Linux system could be placed in different partition, and personal files kept there, so that, if wiping and installing a new OS, these personal "work files" will be retained in the new OS? Now the Tiny core "extensions" seem like a similar idea; (1) keep a clean boot, (2) don't mix up the superfluous with the essential, etc. ( I still "sort of" read the tiny core book... bad student sometimes.).
So, as per your instructions, and my predilection for clutter, I will make a FetchedExts directory, in root (though in truth, I am sometimes perplexed that "/" is root and "/root/" is root? Oh well, I guess we can't all make sense, all the time, and computer programmers are no exception to this rule?)
"Keep a clean boot, be careful not to clutter root, you don't need a Kali TAIL, to onion-out the plain suits"~Adapted/stolen from B. Dylan, by yours truly, just now ...