Nick Taylor

Posted on Jun 16, 2022

June 16th, 2022: What did you learn this week?

#weeklyretro #weeklylearn #discuss

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.

![Image of the brain](https://media.giphy.com/media/ojmB7lOn3VUU8/giphy.gif)

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

#todayilearned

Summarize a concept that is new to you.

Top comments (24)

Jonas Brømsø • Jun 18 '22

You can specify files to be ignored by Dropbox, very useful for folders like node_modules and similar.

I did a brief write up in my TIL collection.

Jonas Brømsø • Jun 18 '22

Oh yeah and I located the Wiki with all of the rules for shellcheck so it will be faster to access the documentation for the specific rules as I am adopting use and making adjustments to some of all my Bash scripts.

Nick Taylor • Jun 18 '22

Ben Lovy • Jun 16 '22 • Edited

Cute trick to inspect your C compiler configuration:

$ gcc -x c -v -E /dev/null
Using built-in specs.
COLLECT_GCC=/usr/bin/gcc
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,objc,obj-c++,ada,go,d,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --enable-libstdcxx-backtrace --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl=/builddir/build/BUILD/gcc-12.1.1-20220507/obj-x86_64-redhat-linux/isl-install --enable-offload-targets=nvptx-none --without-cuda-driver --enable-offload-defaulted --enable-gnu-indirect-function --enable-cet --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux --with-build-config=bootstrap-lto --enable-link-serialization=1
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.1.1 20220507 (Red Hat 12.1.1-1) (GCC) 
COLLECT_GCC_OPTIONS='-v' '-E' '-mtune=generic' '-march=x86-64'
 /usr/libexec/gcc/x86_64-redhat-linux/12/cc1 -E -quiet -v /dev/null -mtune=generic -march=x86-64 -dumpbase null
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/12/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/12/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/x86_64-redhat-linux/12/include
 /usr/local/include
 /usr/include
End of search list.
# 0 "/dev/null"
# 0 "<built-in>"
# 0 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 0 "<command-line>" 2
# 1 "/dev/null"
COMPILER_PATH=/usr/libexec/gcc/x86_64-redhat-linux/12/:/usr/libexec/gcc/x86_64-redhat-linux/12/:/usr/libexec/gcc/x86_64-redhat-linux/:/usr/lib/gcc/x86_64-redhat-linux/12/:/usr/lib/gcc/x86_64-redhat-linux/
LIBRARY_PATH=/usr/lib/gcc/x86_64-redhat-linux/12/:/usr/lib/gcc/x86_64-redhat-linux/12/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/lib/gcc/x86_64-redhat-linux/12/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-E' '-mtune=generic' '-march=x86-64'

You can get just the configuration with a plain gcc -v, but by invoking the preprocessor with -E and pointing it at some nonsense /dev/null, you additionally get to inspect the paths it will use for looking up libraries. Because you passed in something nonsensical, it can't determine what sort of compilation you're doing, so you have to explicitly specify with -x c. This forces it to attempt to preprocess the input as a C program which provides the most complete set of information. Works with clang too.

Handy!

Nick Taylor • Jun 16 '22

Awesome!

Ahmad • Jun 17 '22

I learned how easy it is to make slider menus for webapps!

I was using a library for a react component and it was working great locally but it broke when i was getting folks to test my app : iwannagoapp.com/ (just launched btw , would really appreciate any feedback)

After looking around for a solution, i found a great article with a dozen css lines which just worked

lesson learned: CSS trumps complicated Javascript components any day all day for styling and animation

heres the link to the article:
kirupa.com/react/smooth_sliding_me...

Nick Taylor • Jun 17 '22

That's awesome! 🔥

Nikkhiel Seath • Jun 18 '22

I was going to optimise a piece of code and learnt to never optimise per-maturely.

Always make sure that you keep context in mind when optimising.
O(n) + O(n) where n is just 10 is alright and won't make much of difference if you spend time and make the heuristic O(n).

I am just curious to know, @nickytonline what are you learning these days?

Nick Taylor • Jun 18 '22

For myself, I'm learning Affinity Designer.

Nick Taylor

@nickytonline

I finally got around to buying Affinity Designer @coffeecraftcode. It's amazing! I'd been struggling to make YouTube and Social cards and Affinity Designer made it relatively easy. It came on my radar again after @wesbos mentioned it on a recent Syntax episode. Thanks, peeps!

02:26 AM - 17 Jun 2022