Skip to content

Instantly share code, notes, and snippets.

View liweitianux's full-sized avatar
🎵
Focusing

Weitian LI liweitianux

🎵
Focusing
  • Shanghai, China
  • 12:10 (UTC +08:00)
View GitHub Profile
@thesamesam
thesamesam / xz-backdoor.md
Last active July 8, 2025 19:40
xz-utils backdoor situation (CVE-2024-3094)

FAQ on the xz-utils backdoor (CVE-2024-3094)

This is a living document. Everything in this document is made in good faith of being accurate, but like I just said; we don't yet know everything about what's going on.

Update: I've disabled comments as of 2025-01-26 to avoid everyone having notifications for something a year on if someone wants to suggest a correction. Folks are free to email to suggest corrections still, of course.

Background

@liweitianux
liweitianux / cat-lps.pl
Last active February 21, 2024 12:05
Print lines at particular speed (line/sec)
#!/usr/bin/env perl
#
# Cat file to terminal at particular speed of lines per second
# https://superuser.com/a/526249
#
# Usage: cat-lps.pl [lps] [file]...
#
use warnings;
use strict;
@liweitianux
liweitianux / git-getversion.sh
Last active July 29, 2024 13:37
Generate version information based on Git tags/commits
#!/bin/sh
#
# Generate version information based on Git tags/commits.
#
# License: Public Domain
#
# URL: https://gist.github.com/liweitianux/9fce0fc404c41b8f28512e87fbca1562
#
dirty_mark='+'
@liweitianux
liweitianux / f-stack.installation.md
Last active July 16, 2020 09:39
F-Stack Installation (custom prefix)

F-Stack Installation

  • Author: Weitian LI
  • Date: 2020-07-16

Environment

  • OS: CentOS 7.4.1708
  • Kernel: 3.10.0-957.27.2.el7.x86_64
@liweitianux
liweitianux / dfly-install-hammer2.md
Last active January 2, 2024 06:15
DragonFly BSD Installation (MBR, HAMMER2 boot+root)

DragonFly BSD Installation

1. Create Disk Slice

Assume the disk is /dev/da8, to create a slice of about 100 GB.

dfly# cat > fdisk.conf << _EOF_
@liweitianux
liweitianux / dfly-install.org
Last active February 26, 2023 05:19
DragonFly BSD Manual Installation with HAMMER2 and Encrypted Root

DragonFly BSD Installation

2018-01-30

Disk Partition

MBR Slice

root# dd if=/dev/zero of=/dev/vbd0 bs=32k count=16
root# fdisk -IB /dev/vbd0

Libuv and libev, two I/O libraries with similar names, recently had the privilege to use both libraries to write something. Now let's talk about my own subjective expression of common and different points.

The topic of high-performance network programming has been discussed. Asynchronous, asynchronous, or asynchronous. Whether it is epoll or kqueue, it is always indispensable to the asynchronous topic.

Libuv is asynchronous, and libev is synchronous multiplexing IO multiplexing.

Libev is a simple encapsulation of system I/O reuse. Basically, it solves the problem of different APIs between epoll and kqueuq. Ensure that programs written using livev's API can run on most *nix platforms. However, the disadvantages of libev are also obvious. Because it basically just encapsulates the Event Library, it is inconvenient to use. For example, accept(3) requires manual setnonblocking after connection. EAGAIN, EWOULDBLOCK, and EINTER need to be detected when reading from a socket. This is a

@StevenACoffman
StevenACoffman / fluent-filebeat-comparison.md
Last active June 25, 2025 12:00
Fluentd Fluent-bit FileBeat memory and cpu resources

Fluent-bit rocks

A short survey of log collection options and why you picked the wrong one. 😜

Who am I? Where am I from?

I'm Steve Coffman and I work at Ithaka. We do JStor (academic journals) and other stuff. How big is it?

Number what it means
101,332,633 unique visitors in 2017
@shafik
shafik / WhatIsStrictAliasingAndWhyDoWeCare.md
Last active July 10, 2025 19:24
What is Strict Aliasing and Why do we Care?

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

@robertpainsi
robertpainsi / commit-message-guidelines.md
Last active July 8, 2025 12:01
Commit message guidelines

Commit Message Guidelines

Short (72 chars or less) summary

More detailed explanatory text. Wrap it to 72 characters. The blank
line separating the summary from the body is critical (unless you omit
the body entirely).

Write your commit message in the imperative: "Fix bug" and not "Fixed
bug" or "Fixes bug." This convention matches up with commit messages