November 3, 2025
Kernel of truth?
Linux Tidbits and Collecting Pebbles
Linux ‘tips’ post meets a gentle fact‑check
TLDR: A Linux tips blog post sparked a reality check when a top comment flagged oversimplifications and possible mistakes. Readers debated enthusiasm versus accuracy, reminding everyone that tech advice needs clear, correct explanations so beginners don’t get misled—useful inspiration is great, but verified details matter.
A blogger dropped a grab‑bag of Linux “pebbles”—quick tips about device files, boot helpers, and command quirks—meant to inspire. But the community mood flipped from “aww, neat!” to show your sources fast. The top vibe-setter? supakeen, who politely warned that several claims were oversimplified—or just wrong. For non‑tech folks: Linux is a free operating system, and these tidbits are mini facts about how it starts up, reads files, and handles commands.
That single comment lit the fuse on the classic internet split: enthusiasts who love share‑and‑learn threads vs accuracy hawks who demand receipts. Strongest opinion: helpful lists are great, but bad tips can mislead beginners. The drama circled around specifics like serial ports, “initramfs vs initrd” (two different ways the system preps itself to boot), and whether GNU grep uses PCRE (Perl Compatible Regular Expressions) without actually using Perl. Readers rolled their eyes at naming oddities like “Etc/UTC,” and the “cd..” typo turned into a running gag for command‑line chaos. The meme energy? Imagine a “This is fine” dog next to a booting kernel—funny, but with a serious edge: fact‑check before you publish. The takeaway: the post’s heart was in the right place, but the crowd wants clarity, not mystery riddles.
Key Points
- •/dev is created at boot as a devtmpfs (tmpfs-based) and does not reside on persistent storage.
- •initrd (compressed filesystem) and initramfs (compressed cpio archive) differ in format but both run from RAM during boot.
- •/dev/ttyS serial devices are created based on kernel settings and can be limited via the 8250.nr_uarts boot parameter.
- •Userland behaviors: aliases expand at read-time; in “bash -c” the first argument becomes $0; ls shows file length, du shows disk usage.
- •System and programming notes include: kernel threads fork from kthreadd (PID 2); X events are ordered; rsync checks mtime; Ctrl+C sends SIGINT; C strings are char arrays and stdio char I/O is one byte at a time.