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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 3h

Republicans are cool with Trump murdering random people. I guess at least they go on record saying so, but then again, it's not like there's going to be any consequences anyway. 😡

https://www.nytimes.com/2025/10/08/us/politics/trump-republicans-war-powers-caribbean-venezuela.html

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 15h

I wrote a bit about post-quantum cryptography standards and guidelines beyond those from NIST:

https://www.akamai.com/blog/security/guide-international-post-quantum-cryptography-standards

#PQC

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 15h

Related to our discussion of time(3), here's a deeper dive into the Unix epoch, its origins, and how the Y2K38 issue actually affects different unix systems well before the heat-death of the universe.

https://www.netmeister.org/blog/epoch.html

#apue #Unix #Programming #Time

Time is an illusion, Unix time doubly so...

Unix counts time as seconds since the epoch. Seems straight forward. What could possibly go wrong?

www.netmeister.org

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 1d

Advanced Programming in the UNIX Environment

Week 4: time(3) is an illusion

Having revisited the atime, mtime, and time in our last video segment, we now have to come to terms with time(3) itself. We'll discuss managing the data structures and handling arbitrary concepts such as leap seconds […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 2d

Advanced Programming in the UNIX Environment

Week 4: atime, mtime, ctime

In this video lecture, we start looking a little bit closer into what our systems think of "time", something that experts most accurately describe as a big ball of wibbly, wobbly, timey, wimey... stuff. In short, analyze […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 3d

Advanced Programming in the UNIX Environment

Week 4: getpwuid(2) and /etc/groups

In this video lecture, we look at the library functions used to look up account information. We learn about how primary and supplementary groups are handled as well as how the hashed passwords are stored outside […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 3d

Read somewhere that some AI engines generate images with a “Getty Images” watermark, and I feel like that really sums up a lot.

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Reposted by Jan Schaumann

Walter Olson @walterolson.bsky.social · 4d

All legal nonsense aside about the supposed state of armed conflict between the U.S. and Venezuelan gangs, what "I wish to emphasize is that there is a word for killings outside of armed conflict for which there is no domestic legal authority. That word is murder." [@benjaminwittes.lawfaremedia.org]

The Situation: Murder She Wrote

There's a word for what they're doing.

www.lawfaremedia.org

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 4d

Advanced Programming in the UNIX Environment

Week 4: /etc/passwd

In this short video, we try to answer the awkward question "Mommy, where do UIDs come from?". We look at the /etc/passwd user database and identify the various fields before we look at how things can get weird […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 5d

Advanced Programming in the UNIX Environment

Week 4: Directory Size

In this video lecture, we dive deep into the structure of the directory on a traditional Unix File System and see how its size is independent of the file sizes of its entries, but dependent on the filename lengths. We'll also […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 6d

Advanced Programming in the UNIX Environment

Week 4: Directories

In this video lecture, we take a look at how directories are created and removed, as well as how to move around the filesystem hierarchy. We also learn why the 'cd' command must be a shell builtin in order to work […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 6d

TIL: Wikimedia runs a public DoT / DoH service: https://meta.wikimedia.org/wiki/Wikimedia_DNS

#DNS

Wikimedia DNS - Meta-Wiki

meta.wikimedia.org

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 7d

Advanced Programming in the UNIX Environment

Week 4: Links

In this video lecture, we'll take a look at the system calls used to create, remove, and rename both hard- and symbolic links. We'll compare expected output against trivial implementations of the ln(1) […]

[Original post on mstdn.social]

Links
--------
You now can implement ln(1), mv(1), and rm(1).

The link count (st_nlink) keeps track of how many names for a file exist; if this count is 0 and no process has a file handle open for this file, the data blocks may be released.

Renaming a file on the same filesystem is trivial, but renaming across filesystems and between files and directories requires a little bit more work.

Symbolic links can link to any file regardless of type, existence, or filesystem / device location.

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 7d

@SteveBellovin Those made me gag in CA last week.

Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 8d

It's been well over 30 years since I last read him, but yeah, Bukowski is still solid.

Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 8d

Advanced Programming in the UNIX Environment

Week 4: The Unix Filesystem

In this video lecture, we begin a closer look at the Unix Filesystem (UFS). We visualize how the filesystem structures the disk and organizes files and directories. We illustrate how […]

[Original post on mstdn.social]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 9d

Advanced Programming in the UNIX Environment

Week 3: Union Mounts and Whiteout Files

One of the file types we've encountered are those of type S_IFWHT, so called "whiteout" files. But what the hell is that?? Let's illustrate! We describe the concept of union mounts and see what happens when a […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 10d

Advanced Programming in the UNIX Environment

An illustration of how permission octal modes and umasks work.

#apue #Unix #Programming

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 11d

Man, watching anything about Los Desaparecidos during Argentina’s Dirty War reeeeaalllly hits different this year.

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 11d

Advanced Programming in the UNIX Environment

Week 3: umask(2)

In this video lecture, we'll take a look at what file ownership and permissions are applied when we create a new file. In the process, we'll learn about the concept of a process's "umask", and look at how the 'umask' shell built-in […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 12d

But let me also be the n-th person to recommend you "More Everything Forever" by Michael Becker to better understand Silicon Valley megalomania (and the absurdity of the "effective altruism" ⋂ AI cult).

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 12d

Steven Levy's latest article "I Thought I Knew Silicon Valley. I Was Wrong" in Wired is pretty good.

"Tech got what it wanted by electing Trump. [...] turns out that you can run pretty well on a bended knee."

https://www.wired.com/story/silicon-valley-politics-shift/

A number of Silicon Valley leaders portrayed as kneeling in front of and praising Donald Trump

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 13d

Over the last few months, I've repeatedly had people tell me about how "well, the Military will refuse an illegal order", to which I can only gesticulate in a bewildered manner in the direction of at least 17 dead from the Venezuelan boats they happily blew up, why not.

And the third one barely […]

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Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 13d

@SteveBellovin I’ve had good experiences with Airalo in Europe, Japan, Argentina.

Jan Schaumann @jschauma.mstdn.social.ap.brid.gy · 13d

Advanced Programming in the UNIX Environment

Week 3: chmod(2) and chown(2)

Having seen a lot of examples in our previous videos of creating files, changing their ownership, changing their permissions, we now focus on the system calls that are used to implement the chmod(1) and chown(8) […]

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