FSMaxB @FSMaxB@mastodon.cloud

Today's tip: Don't partition already partitioned data using the same hash function that it has already been partitioned with.

Or: Application specific keys for hash functions are there for a reason, don't use the same for different applications.

Key takeaway: Consider your /etc/shadow to be containing essentially plain text passwords.

-> Don't reuse Linux login passwords for anything else
-> Encrypt your system partition (and be sure to configure a sensible key derivation function when setting it up using cryptsetup, I don't think they use sensible defaults yet. In other words: Tell cryptsetup to use Argon2id and optimise --iter-time and --pbkdf-* to be as slow and memory consuming as acceptable)

OMG, why can't we have nice things. Just found out that passwords in /etc/shadow are hashed using SHA-512 by default (which is the least bad option ...) but only 5000 rounds by default (not that more rounds would make it significantly more resistant against brute force in any case).

Today: Have you ever looked at the semantics of "round" in your programming language. Look at JavaScript and Python for example.

The biggest unsolved problems of applied computer science:
* floating point numbers
* date/time
* text

Just found some interesting code in jemalloc's implementation of a mutex:

if (ncpus == 1) {
goto label_spin_done;
}

https://github.com/jemalloc/jemalloc/blob/1df9dd35154ca460facbd74f779a13dcece78dac/src/mutex.c#L51-L53

Microsoft just open sourced their STL implementation! https://devblogs.microsoft.com/cppblog/open-sourcing-msvcs-stl/

"Smooth GNOME experience in a wie variety of devices" https://www.youtube.com/watch?v=qAjPRr5SGoY&feature=youtu.be

I quite like the idea of the new operator, although I think it looks ugly.

Mozilla-Survey about JavaScript evolution: https://hacks.mozilla.org/2019/05/javascript-and-evidence-based-language-design/

I published my first rust library: https://crates.io/crates/adjacent-pair-iterator

#/usr/bin/env bash
for string in 1{,+,-}2{,+,-}3{,+,-}4{,+,-}5{,+,-}6{,+,-}7{,+,-}8{,+,-}9; do
result=$(($string))
if [[ $result == 100 ]]; then
echo $string
fi
done

Then I came up with a solution in #bash that took me ~5 minutes to write but with an execution time of 20s.

123+45-67+8-9
123+4-5+67-89
123-45-67+89
123-4-5-6-7+8-9
12+3+4+5-6-7+89
12+3-4+5+67+8+9
12-3-4+5-6+7+89
1+23-4+56+7+8+9
1+23-4+5+6+78-9
1+2+34-5+67-8+9
1+2+3-4+5+6+78+9

At first I came up with a solution in JavaScript.
time spent: 22min
execution time: ~170ms
loc: 21

At todays C++ meetup I was told a programming quiz:

Given the digits 1-9 (in that order), you can combine them with either '+', '-' or nothing.
Now find all of these mathematical terms, that evaluate to 100.

You can use any programming language and library you like and you have 1 hour to complete the task.

Interesting. I just found out that ldd is a shell script.