Linux

This is really good. Clear and well laid out.

The only thing that might confuse some beginners is your specific choice of package manager.

Interesting compilation, there is cheat.sh, tldr and others though

Nice work.

My tiny nitpick is that "touch" will create the file you specify if it doesn't exist. I've seen this usage a lot, so your example may benefit from mentioning it.

Thanks for all the feedback! I'm much happier with it now, and I'll probably continue to make small changes over time.

I find the references to file extension kinda confusing. Extensions mean a lot less in Linux cli, but I can tell youre just using them for examples. Maybe give more concrete examples instead.

ls *.sh to list all the files ending in .sh

I don't know how this would be useful to someone reading the cheat sheet, but here's something interesting I just indirectly found out while skimming it through:

Ctrl+D does the same thing as ENTER, except the latter additionally sends the end-of-line character to the reader while the former sends nothing;
as is the case for shells or interactive programs like the Python REPL, Ctrl+D causes them to terminate only because it sends a string that is 0 characters long, and 0-size reads are universally interpreted as files reaching the end.

To test this: enter cat, type "hello" without pressing enter, then Ctrl+D: you should see "hellohello".
An extremely rare case of this being useful would be using netcat to send a string somewhere, without sending the end-of-line byte at the end.

Oh. My. Gosh. I love this. Thank you. And thank you for being --verbose about the provenance and history of the document. And big big thank yous for the Internet Archive links. Bravo.

Cool, thank you!

What do you mean about "/ root directory, eg /usr/bin/bash"? / is /, just the top-most directory

would you upload this on github?

cd - changes to the previous directory

I've been using Linux for decades and I bet that'll still come in handy.

You might consider putting a license on it

This is fantastic. Just at a glance I already learned something new! Definitely keeping this for reference.

^S - stop terminal IO
^Q - resume terminal IO (if your terminal looks frozen, this is the one to try)
alt-b, alt-f - jump back/forward one word

This is really nice!

Aren't Alt + Backspace, and Alt + Arrow Key Left/Right also terminal shortcuts?

I like your version, I am bookmarking it.

This is really helpful, thank you.

You're a prince among men.

Really cool!
Another good addition to this might be some script rudiments, like how to write and run simple .sh files

I owe you bigly

Awesome! Thank you kindly

Great idea. I'll keep this handy from now on.

At the end, in redirection, <<: that's not how here-documents work. The example gives the impression it will read the given file up until "STOP", but in reality the shell expects you to keep writing your here-doc until you write "STOP" and then feeds it to the program as if it were all on stdin. I don't think wc even does anything with the stdin if you give it a filename... Note that variable expansion will happen in here-docs, so it's a bit different than a simple cat. Also look into here-strings. And process substitution, I find that quite handy.

A little over a decade & a half and I find that very useful. Should have GPG in for reading signatures on software and such too. If you'd like I can contribute to GPG terminal as I've been using it for a good portion of that time.

I've needed something like this for a while, thank you buddy

Alt + . inserts the last argument from the last command run into the current line. I find it helpful all the time.

less can be invoked directly, without having to be piped from cat: less <file> is mostly equivalent to cat <file> | less
I have considered making an alias/function that automatically determines if the file is longer than the terminal, using something like wc -l and stty -a | grep -oP "rows \d" and then either uses cat or less depending on that... but I already use sharkdp's bat, which has that baked in as well as many other conveniences

Don't forget tail -f <file> which is kind of like watch tail <file>

If you're going to have du, I would also have a section for df, I use the latter more often (but probably because I have like 5 mounts for my OS). Using them in combination is basically what all the gui disk usage analyzers do; something like df -h "oh, /var's almost full" (as previously mentioned, I have different folders on different partitions), then du -ah /var and so on to find problem areas

The "installing from source" section works maybe 50% of the time. It assumes a configure script, which isn't always the case. I've had a lot of source that comes bundled the way a .deb does: basically a compressed filesystem that assumes the $CWD is / (basically, if you uncompressed it in /, all the files would go where they needed to be). Sometimes they use language-specific build systems, so you might need go and rust and... Maybe it's best to just keep it your way and look up the rest, but do keep in mind the thing I said about compressed filesystems

find is great if you want to reindex everything from square 0; or if you only need to do small directory/tree. If you have the extra space to spare, install locate: it indexes the files beforehand (as a cron job) and yields results more quickly for searches that span entire filesystems; the only downside is that you have to manually reindex (sudo updatedb) to locate files installed the same day

In the Extracting, Sorting, and Filtering Data section, you might consider adding in sort -u and uniq which fill their own (overlapping) niches. sed and awk may be a bit more than beginner, but they are endlessly helpful. tr can be a useful shorthand for when cut and sed don't quite cut it, but you don't want to build a full in-line awk script.

Finally:

<command> 2>&1 <file> | Output and errors from <command> are redirected and appended to <file>

Should read "Output and errors from are redirected to " because the single > overwrites the existing file, as opposed to >> which, as you noted, appends to the end of the file