Anagh Kumar Baranwal darthShadow

## latency.markdown

      
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                hellerbarde
                / latency.markdown
            
            
              Created
              May 31, 2012 13:16
                — forked from jboner/latency.txt
            
              
                Latency numbers every programmer should know
              
          
    Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

  
## System Design.md

      
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                vasanthk
                / System Design.md
            
            
              Last active
              August 23, 2024 19:56
            
              
                System Design Cheatsheet
              
          
    System Design Cheatsheet


Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps


Clarify and agree on the scope of the system


User cases (description of sequences of events that, taken together, lead to a system doing something useful)

Who is going to use it?
How are they going to use it?


## AuthyToOtherAuthenticator.md

      
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                gboudreau
                / AuthyToOtherAuthenticator.md
            
            
              Last active
              August 24, 2024 21:08
                — forked from Ingramz/AuthyToOtherAuthenticator.md
            
              
                Export TOTP tokens from Authy
              
          
    Generating Authy passwords on other authenticators


*update: TBC, but this new might affect how easy it is to use this technique past August 2024:
Authy is shutting down its desktop app | The 2FA app Authy will only be available on Android and iOS starting in August

This gist, based in part on a gist by Brian Hartvigsen, allows you to export from Authy your TOTP tokens you have stored there.

Those can be "standard" 6-digits / 30 secs tokens, or Authy's own version, the 7-digits / 10 secs tokens.

  
## fish_install.md

      
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                gagarine
                / fish_install.md
            
            
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              August 13, 2024 20:13
            
              
                Install fish shell on macOS Mojave with brew
              
          
    Installing Fish shell on MacOS (Intel and M1) using brew

Fish is a smart and user-friendly command line (like bash or zsh). This is how you can instal Fish on MacOS and make your default shell.
Note that you need the https://brew.sh/ package manager installed on your machine.
Install Fish

brew install fish

  
## macOS-IPv6-Tunnel-DNS-HOWTO.md

      
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                smammy
                / macOS-IPv6-Tunnel-DNS-HOWTO.md
            
            
              Created
              December 13, 2018 19:14
            
              
                How to convince macOS to do IPv6 DNS lookups when your only IPv6 address is via a VPN or tunnel of some sort
              
          
    This was a huge hassle to figure out, so I wrote up a little guide in hopes that others would find it helpful:
How to convince macOS to do IPv6 DNS lookups when your only IPv6 address is via a VPN or tunnel of some sort

The Problem

macOS's domain name resolver will only return IPv6 addresses (from AAAA records) when it thinks that you have a valid routable IPv6 address. For physical interfaces like Ethernet or Wi-Fi it's enough to set or be assigned an IPv6 address, but for tunnels (such as those using utun interfaces) there are some extra annoying steps that need to be taken to convince the system that yes, you indeed have an IPv6 address, and yes, you'd like to get IPv6 addresses back for DNS lookups.
I use wg-quick to establish a WireGuard tunnel between my laptop and a Linode virtual server. WireGuard uses a utun user-space tunnel device to make the connection. Here's how that device gets configured:

  
## airvpn.md

      
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                e00E
                / airvpn.md
            
            
              Last active
              October 3, 2023 20:28
            
              
                Why does a client connected to the AirVPN vpn service prefer IPv4 over IPv6 addresses?
              
          
    Question

Forum topic: https://airvpn.org/topic/25140-the-issue-your-browser-is-avoiding-ipv6/
Ipv6 test: http://test-ipv6.com/
In the forum thread AirVPN writes:

Our assigned ULAs are in fde6:7a:7d20::/48 which is inside the range officially reserved to ULA so we don't understand why a browser should discriminate against them in favor of a local IPv4 address...

I hope to answer this question in this document.

  
## calisuck.py
#!/usr/bin/env python3

'''
calisuck: index, filter-out smartly and download ebooks from Calibre open directories

Installation:

    You need python 3.5 installed

    Download the file as a zip and unzip-it and get into the dir

## Android-SHIELD Android TV.xml
<!-- Put in ./Library/Application Support/Plex Media Server/Profiles/Android-SHIELD Android TV.xml -->
<!-- Author: Donald Webster fryfrog@gmail.com -->
<?xml version="1.0" encoding="utf-8"?>
<Client name="SHIELD Android TV">
  <Identification>
    <Header name="User-Agent" substring="SHIELD Android TV" />
  </Identification>
  <TranscodeTargets>
    <VideoProfile container="mkv" codec="h264" audioCodec="aac" context="streaming" />
    <MusicProfile container="flac" codec="flac" id="StereoMusicTranscodeProfile" />

## .env
UID=1000
TLD=mydomain.com

# ACME
ACME_EMAIL=admin@mydomain.com
CLOUDFLARE_EMAIL=admin@mydomain.com
CLOUDFLARE_API_KEY=xxxx

# OAUTH
OAUTH_CLIENT_ID=xxxx

## lambda_function.py
#
# This microservice links HetrixTools and Twilio together through webhooks.
# If HetrixTools detects downtime, this microservice is called, which calls your phone/SIP number
# and announces which monitor detected an issue using TTS.
#
# GET Parameters:
# - token = Must match SecretKey
# - repeat = How many times should the message be repeated (optional, default 2)
# - to = Which number / SIP destination to call
#
	#!/usr/bin/env python3

	'''
	calisuck: index, filter-out smartly and download ebooks from Calibre open directories

	Installation:

	You need python 3.5 installed

	Download the file as a zip and unzip-it and get into the dir
	<!-- Put in ./Library/Application Support/Plex Media Server/Profiles/Android-SHIELD Android TV.xml -->
	<!-- Author: Donald Webster fryfrog@gmail.com -->
	<?xml version="1.0" encoding="utf-8"?>
	<Client name="SHIELD Android TV">
	<Identification>
	<Header name="User-Agent" substring="SHIELD Android TV" />
	</Identification>
	<TranscodeTargets>
	<VideoProfile container="mkv" codec="h264" audioCodec="aac" context="streaming" />
	<MusicProfile container="flac" codec="flac" id="StereoMusicTranscodeProfile" />
	UID=1000
	TLD=mydomain.com

	# ACME
	ACME_EMAIL=admin@mydomain.com
	CLOUDFLARE_EMAIL=admin@mydomain.com
	CLOUDFLARE_API_KEY=xxxx

	# OAUTH
	OAUTH_CLIENT_ID=xxxx
	#
	# This microservice links HetrixTools and Twilio together through webhooks.
	# If HetrixTools detects downtime, this microservice is called, which calls your phone/SIP number
	# and announces which monitor detected an issue using TTS.
	#
	# GET Parameters:
	# - token = Must match SecretKey
	# - repeat = How many times should the message be repeated (optional, default 2)
	# - to = Which number / SIP destination to call
	#