Articles in english
Item 19: Use interfaces only to define types
In the book Effective Java 2nd edition, the item 19 stipulates to "use interfaces only to define types" and not to use them to define constants.
Emacs Module : Test 1
Since I've heard about Emacs' Dynamic Module feature, I've wanted to try it out. This article presents a small "hello world" with this feature.
Exploring the Wildcard Capture Pattern in Java Generics
While I was reading the Java Specification and Java Tutorials, I stumbled upon the "wildcard capture pattern" and the "Object cannot be converted to CAP#1" error.
When Good Code Goes NaN: How mismanaging Java's Unorderable NaN Value led to a bug
I recently encountered a bug which was caused by a NaN value in my Java code. NaN, short for "Not a Number", is a valid value for a float or a double. NaN is a tricky value because (1) it spreads like a virus and (2) it is unorderable.
Dumping a binary file with od(1)
I was recently working on an embedded device that provided a limited CLI interface and was looking for an utility to dump a binary file.
I was aware of hexdump(1) but alas, it was not available on my platform. That is how I discovered od(1).
Reducing PDF filesize with the Command Line using Ghostscript (gs)
I use the following command line to reduce the PDF filesize:
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf
This command line can be used to reduce the PDF filesize on Linux.
Emacs #filename# ???
Sometimes Emacs saves a file under #filename# instead of filename. That's because of auto-save. To disable this behavior while keeping the benefit of auto-save enable auto-save-visited-mode.
How to check ssh public key fingerprints?
The authenticity of host omecha.info (89.234.176.136)' can't be established. ECDSA key fingerprint is SHA256:v7u4albDUtGH1EXWEwlt0KnzY9GDY5EqodUymKSbiSw Are you sure you want to continue connecting (yes/no)?
If you have ever used SSH, you have encountered this prompt. If you often SSH to new machines and you are like me, you probably type 'yes' without thinking about it.
In this article I describe how you can check your SSH fingerprints.
SSH escape commands for fun and profit
We can never say it enough, but OpenSSH is an amazing tool. Lately, I have been playing with VMs and a friend of mine showed me some really cool tricks with SSH. The SSH escape ~ commands!
How to get started in infosec?
I am keeping here a a list of all articles I find on "getting started in infosec" and try to summarize their content in one list. This is not really meant to be public, it is just for me to centralize all this information.
org-capture freezes emacs on OpenBSD
I've switch recently to OpenBSD and I noticed that org-capture no longer worked. Worst, it freezes my emacs session, which is something that should never happen. So, time to do a little Emacs Debugging Session !
Update 2021-07-14: We fixed this issue with jca@: https://marc.info/?l=openbsd-ports&m=162628497223780&w=2
Beyond the tutorial : Text Classification with sklearn
The goal of this article is to show how you can go beyond the simple pipeline presented in the sklearn tutorial. I assume you've read and coded the tutorial. I start by reviewing the code, recalling how it works and pointing out few problems you might encounter when you want to develop a more complex pipeline to process text data.