True words

In Bash, the history command is capable of much more than what’s been covered here, but this is a good start for getting used to using your history instead of just treating it as a reference. Use the history command often, and see how much you can do without having to type commands. You might surprise yourself!

I recently noticed that zsh and fish will instead show a character indicating a missing linefeed, and still start the prompt where you’d expect to find it:

vidarholen-vm2% echo -n "hello zsh"
hello zsh%
vidarholen-vm2%

If you’re disappointed that this is what there’s an entire blog post about, you probably haven’t tried to write a shell. This is one of those problems where the more you know, the harder it seems

[…] the signal name stands for "Segmentation Violation".
So it’s essentially: SIGnal SEGmentation Violation.

But there’s more!

Originally the signal was called SIGSEG. It was subsequently renamed SIGSEGV
in the userspace and a bit later - around 1980 - to SIGSEGV on the kernel
side.

Maersk is the world’s largest integrated shipping and container logistics company. I was massively privileged (no pun intended) to be their Identity & Access Management (IAM) Subject Matter Expert (SME), and later IAM Service Owner. Along with tens (if not hundreds) of others, I played a role in the recovery and cybersecurity response to the events of the well-publicised notPetya malware attack in 2017. I left Maersk in March 2019, and as is customary I wrote the obligatory thank you and goodbye note. But there was always a lot more to add. A story to tell.

In order to contribute to historical awareness in our field, we have compiled a list of interaction design classics. Our aim was to include examples that we find inspiring and insightful — which led to our greatest challenge, keeping in mind that we wanted to create a concise list — leaving things out. So, we decided to focus on productivity software — in a very broad sense — and to order the projects chronologically. We didn’t address user interfaces from games, websites or artistic projects; that really would have been too much.

Notice the line makepdf & makedoc & openapp. Here I am are running the 3 functions in parallel. The wait command does exactly that, waiting for the previous things to finish. When everything is done, the pdf file opens. Let’s look at the timing now:

real 0m24.677s
user 0m21.669s
sys 0m1.746s

It is running ~27% faster. Only by wrapping the code in different functions.

As an extra, in bash the code is not evaluated all at once. If you edit a script while it is being executed, the script behaves differently. Wrapping it in functions solves that problem too.