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@jschauma.mstdn.social.ap.brid.gy Sep 26, 2026, 3:33 PM

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 […]

@hugovalters.bsky.social Sep 26, 2026, 2:30 PM

Authenticate local IPC clients via SO_PEERCRED — kernel-captured PID/UID/GID, spoof-proof. Build a Unix domain socket server with UID enforcement.
https://www.valtersit.com/vault/unix-domain-socket-server-with-sopeercred-uid-enforcement-bf3ac2/
#python #unix-socket #ipc

@admin-magazine.com Sep 25, 2026, 8:30 PM

Have you seen the new Best of Bash special edition? Deepen your command-line experience with the premier edition. Buy it with the Linux Shell Handbook and save 15%

shop.linuxnewmedia.com/shop/categor...

#Shell #Bash #Linux #CommandLine #Unix #utilities #scripting

BEST of BASH: Unsung Tools for the Shell | Move faster and reach farther with better command-line tools

@jschauma.mstdn.social.ap.brid.gy Sep 25, 2026, 6:03 PM

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) […]

@lobsters-feed.bsky.social Sep 25, 2026, 5:19 PM

Terminally confused (2012) https://lobste.rs/s/btdpiy #unix

@jordanjmc.bsky.social Sep 25, 2026, 4:14 AM

Source ancestry and standards answer different questions about UNIX.

A system can implement standardized Unix interfaces without descending from Bell Labs source.

Ask both: Where did its code come from, and what standards does it implement?

excalibursheath.com/article/2026...

#UNIX #POSIX

@linux-magazine.com Sep 24, 2026, 9:15 PM

Have you seen the new Best of Bash special edition? Deepen your command-line experience with the premier edition. Buy it with the Linux Shell Handbook and save 15%

shop.linuxnewmedia.com/shop/categor...

#Shell #Bash #Linux #CommandLine #Unix #utilities #scripting

@jschauma.mstdn.social.ap.brid.gy Sep 24, 2026, 6:42 PM

Advanced Programming in the #UNIX Environment

Week 3: struct stat st_mode

In this video segment, we're looking at how the traditional permissions defined in the `struct stat st_mode` are applied. You want to pay particular attention to the permissions on […]

[Original post on mstdn.social]

The st_mode also encodes the file access permissions (S_IRUSR, S_IWUSR,
S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP, S_IROTH, S_IWOTH, S_IXOTH). Uses of
the permissions are summarized as follows:
• To open a file, need execute permission on each directory component of the path.
• To open a file with O_RDONLY or O_RDWR, need read permission.
• To open a file with O_WRONLY or O_RDWR, need write permission.
• To use O_TRUNC, must have write permission.
• To create a new file, must have write+execute permission for the directory.
• To delete a file, need write+execute on directory, file doesn’t matter.
• To execute a file (via exec family), need execute permission.

Which permission set to use is determined (in order listed):
1. If effective-uid == 0, grant access
2. If effective-uid == st_uid
2.1. if appropriate user permission bit is set, grant access;
2.2. else, deny access
3. If effective-gid == st_gid
3.1.if appropriate group permission bit is set, grant access
3.2. else, deny access
4. If appropriate other permission bit is set, grant access, else deny access

@eulinuxevolutionde.eurosky.social Sep 24, 2026, 12:05 PM

Unix-Betriebssystem: NetBSD 10.2 verbessert Hardware-Unterstützung & Sicherheit
www.computerbase.de/news/betrieb...

#Unix #Linux #LinuxNews #LinuxDE #LinuxNewsDE #EULE #EULEde #NetBSD #NetBSD10_2

@myrkraverk.bsky.social Sep 24, 2026, 10:59 AM

/Understanding and Using COFF/. This brand new #book, first published in 1988, explains the intricacies of the #UNIX Common Object File Format.

Written by Gintaras R. Gircys, this #nonfiction is highly sought after by all #SysV aficionados.

@computerbase.de Sep 24, 2026, 5:30 AM

Unix-Betriebssystem: NetBSD 10.2 verbessert Hardware-Unterstützung & Sicherheit #netbsd #update #unix

@jschauma.mstdn.social.ap.brid.gy Sep 23, 2026, 9:10 PM

Advanced Programming in the #UNIX Environment

Week 3: UIDs and GIDs

In this video lecture, we'll learn a little bit more about file ownership and the user IDs of a process (real, effective, saved) by looking at the seteuid(2) and setuid(2) system calls and experimenting with setting the setuid […]

@jschauma.mstdn.social.ap.brid.gy Sep 23, 2026, 9:10 PM

Advanced Programming in the #UNIX Environment

Week 3: UIDs and GIDs

@moellus.wandzeitung.xyz.ap.brid.gy Sep 23, 2026, 1:54 PM

"Year of the Amiga Unix Desktop 2026" https://amigaux.org/ /via #golem #amiga #unix

@jschauma.mstdn.social.ap.brid.gy Sep 22, 2026, 3:09 PM

Advanced Programming in the #UNIX Environment

Week 3: stat(2) intro

In this video lecture, we meet our new best friend, the 'struct stat'. We'll cover the stat(2) system calls and begin discussing each of the fields in the struct, often by example of the ls(1) […]

[Original post on mstdn.social]

$ ls -l file
-rw-r--r-- 1 jschauma wheel 1048576 Sep 10 20:04 file

"-rw-r-r-" from st_mode
1 st_nlink
"jschauma" from st_uid
"wheel" from st_gid
1048576 st_size
Sep 10 20:04 from st_mtime
file not from stat at all

The stat(1) utility displays information about the file pointed to by file.

$ stat -r file
16 3 0100644 1 1000 0 -1 1048576 1599768274 1599768274 1599768274 0 4096 2056 0 file

The default format displays the st_dev, st_ino, st_mode, st_nlink, st_uid,
st_gid, st_rdev, st_size, st_atime, st_mtime, st_ctime, st_birthtime,
st_blksize, st_blocks, and st_flags fields, in that order.

@rmathew4bs.bsky.social Sep 22, 2026, 1:09 PM

That #logo doesn’t spell a word every way like the #Sun logo does 🧐:

“What Sun Got Wrong”, Bryan Cantrill (bcantrill.dtrace.org/2026/09/20/w...).

On HN: news.ycombinator.com/item?id=4978...

#Solaris #SPARC #Unix #Workstations #Business #Nostalgia #Dell #Sales

@n.gotosocial.tourmentine.com.ap.brid.gy Sep 22, 2026, 9:50 AM

[lien] Commodore's forgotten Amiga Unix gets a modern revival #amiga #unix #gik #90s

@kiteh.net Sep 22, 2026, 6:36 AM

#Nostr #Unix #ATT #FreeSpeech
www.youtube.com/watch?v=wVor...