October 22nd, 2021: What did you learn this week?

It's that time of the week again. So wonderful devs, what did you learn this week? It could be programming tips, career advice etc.


Feel free to comment with what you learnt and/or reference your TIL post to give it some more exposure.

#todayilearned Follow

Summarize a concept that is new to you.

Comments

[Andrew McIntosh]

(Re)learning some PHP for a side project. It's been a few years and I never really knew PHP well in the first place. Getting reused to the syntax and learning about PHP 8 changes.

[Nick Taylor]

[Ben Halpern]

I dug into signed exchanges a bit today. I was vaguely familiar before, but it clicked.

[Nick Taylor]

[Amrin]

crap i didn't learn anything new this week.

[Ben Halpern]

😮

[Nick Taylor]

No worries friend!

[Amrin]

Thanks Nick ;)

[Stephen Belovarich]

I learned there is a computer out there I can still be excited about. M1 Max MBP 🏎

[Nick Taylor]

[Igor Soroka]

I learned how to provision the whole CI/CD pipeline with AWS CDK in less than 40 lines of Typescript code :)

[Nick Taylor]

[Godswill Umukoro]

Thanks for asking, here's something interesting I learned this week
dev.to/godswillumukoro/css-is-awes...

[Nick Taylor]

[Heiker]

I used xargs this week.

It looks like the open command can't take data from the standard input, so I ended up using something like this.

some_command | xargs -r -I{} open {}

For those who don't know, xargs (with the right arguments) can act like the map method on javascript arrays. So you can imagine the above doing something like this:

some_command().map(arg => open(arg))

[Nick Taylor]

Nice!

[grendel]

xargs can come in handy in a pinch, but it's usually unnecessary and the way it generates arguments can cause some complications. I can't think of a case where xargs would be more appropriate than Command Substitution or a while read loop, e.g.:

open "$(some_commands)" #thus you fully control word-splitting

or

some_commands | \
  while IFS= read -r line; do #unsetting IFS here prevents word-splitting
    some_other_commands "$line"
    even_some_more_commands "$line"
    #vars declared in here are not valid afterwards,
    #since they are declared inside the pipeline subshell
    #and its environment does not hoist
    #This includes $line
  done

#alternatively, using process substitution:
while IFS= read -r line; do
  some_other_commands "$line"
  #variables set here remain valid afterwards
  #since this while-loop is not in a subshell
  #thus the last $line will remain set afterwards
done < <(some_commands)

With process substitution and the mapfile builtin, you can even populate an array and iterate over that:

mapfile -t arr < <(some_commands)
#synonym: readarray -t arr < <(some_commands)

for elem in "${arr[@]}"; do
  some_stuff_with "$elem"
done
# or:
for ((i=0; i<${#arr[@]}; i++)); do
  some_stuff_with "${arr[$i]}"
done

[Matthew Foley]

In progress learning about conventional commits! github.com/open-sauced/open-sauced...

[Nick Taylor]

Nice! You might also be interested in Conventional Comments! I gave a lightning talk about them last year as part of my Virtual Coffee group's lightning talk series.

I'm on at this point.

[Fyodor]

SvelteKit and Strapi. They're really cool. Gonna start a pet project to get deeper.

[Nick Taylor]

[Kirk Shillingford]

Learned about HSL for color in css. Seems way more intutive than RGB or hex codes and I'm going to incorporate it into my front end design more.

[Nick Taylor]

Yeah!