Back in the 80s/90s there were keyrings that would play an alarm if they heard a whistle at a particular frequency. You're basically playing Marco Polo with your keys.

I assume they lost popularity because the batteries tended to run out at inopportune times. Batteries are better now. Maybe it's time those things made a comeback.

3. If you want to split a delimiter separated line and print some field, you need cut. Keep awk for more complicated tasks.

Depends on the delimiter too! For anyone else reading this, sed accepts many kinds of delimiters. sed "s@thing@thing2@g" file.txt is valid. I use this sometimes when parsing/replacing text with lots of slashes (like directory lists) so I can avoid escaping a ton of stuff.

agree with one and two and younger me would have agreed with your third point but I think I don't anymore.

yes cut is the simpler and mostly functional tool you need for those tasks.

but it is just so common to need a slight tweak or to want to substitute something or to want to do a specific regex match or weird multi character delimiter or something and you can do it all easily in awk instead of having to pipe three extra times to do everything with the simplest tool.

That's wild to me, as I used sed all the time. Quickly and easy changes in configs? Bam sed. Don't even need to open vi when I can grep for what I need, then swap it with sed. Though I imagine more seasoned vi nerds would be able to do this faster.

If you're using find all the time, check to see if you have or can have some variant of locate installed. It indexes everything* on the system (* this is configurable) and can be queried with partial pathnames, even with regex, and it's fast.

sed is not for daily use, it is for reusable scripts. For other purposes interactive editors are more convinient.

I don't know what OP used, but it could be any one of the Markdown presentation tools.

I like reveal.js

Your presentation can go in git, looks good anywhere, and easily shared. It's just html rendered.

In most cases extended POSIX regexes are enough and looks the same as perl regexes.

I also used perl until I needed to write highly portable scripts that can be run on systems without perl interpreter (e.g. some minimal linux containers). Simple things are also simple to do with grep/sed/awk, more complex things can be done with awk but require a longer code in comparison with perl.