• DNS cannot mapping to subfolders

  DNS can only map to an host/IP address, but not path / port.

  What you ask for requires URL forwarding/redirecting, and is not about DNS records.

  You will need a web server to redirect by HTTP 301.

• If /android or /ios is missing under project volume:

  1 2	react-native upgrade # optional react-native eject

• react-native run-ios: xcrun: error: unable to find utility “instruments”, not a developer tool or in PATH
  error Command failed: xcrun instruments -s
  xcrun: error: unable to find utility “instruments”, not a developer tool or in PATH

https://stackoverflow.com/questions/42506068/how-can-i-regenerate-ios-folder-in-react-native-project

• Declarative

• Component-based

  encapsulate behaviors into small units called Components
  Components are made of elements.
  Components enable us to break down the entire UI in to smaller reusable pieces.
  can have private states to control.
  Only class components can store states.

• Component Methods

• Component State and Lifecycle

• Element

  smallest building blocks is elements.

• Basic structure for a component

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

  import React, { Component } from 'react'; class Menu extends Component { constructor(props) { super(props); // Need to supply this props to the super class } render(){ return( // the view for this component ); } } export default Menu; //need to import this component for wherever we use

• Every parameter pass to the component is under props.

• If one component export the default one, there is no need to enclose import component name with braces, otherwise error occurs.

• JSX: wrapped React Component expression

• Handling events like handling DOM elements

• Container

  Whatever is enclosed inside <div class="container"></div> will be restricted to the same width as the rest of the Web page.

• Material Design

  Indeed, If you have interest where I found this colors you can visit www.android.com and then look up their documentation for material design and there, they have suggestions for how colors can be used in your Android application but the same thing applies even to a website.

• Column classes

  • col, col-x, col-auto
  • col-xx-x
  • order-xx-first/last
  • offset-xx-x

• Button class btn-block

• Variation hoisting

• Global or local variable?

  var/const/let/[none]

• Arrow function

  this reference

• View Source vs. Inspect Element

  Not always the same. View Source for server-side HTML and Inspect Element for current state of DOM tree.

• Find standard compliant information for attributes

• Check browser compatibility

• A “div” generic container occupies 100% horizontally by default.

• NoSQL is non-relational

• ACID-compliant (only just recently with MongoDB)

  • Atomic/Atomacity: A change will not be saved but rolled back unless the entire transaction is completed.
  • Consistency: No intermediate state from one valid state to another. Always valid states.
  • Isolation: The effect of more than one concurrent transactions is the same as if they happen in sequence.
  • Durability: The data is there no matter whether database is shutdown, failures or crashes.

• Git switch remote origin

  1 2 3 4

  $ git remote rm origin $ git remote add origin <repository> $ git config master.remote origin $ git config master.merge refs/heads/master

• Git change the commit author

  But the SHA1 code changes after revision.

• Git add submodule reference

  1	git submodule add <repository<path>

  check .gitmodules for details.

• Git clone submodule references

• Git remove submodule reference

  1 2 3

  git submodule deinit <path_to_submodule> git rm [-r] [--cached] <path_to_submodule> git commit -m "Removed submodule"

  rm -rf .git/modules/

• Git submodule HEAD detached

  Update .gitmodule and specify the branch of submodule to track. Then reload:

  1 2	git submodule sync git submodule update --init --recursive --remote

  Or re-add the submodule:

  1 2	git submodule add -b <branch<repository[<submodule-path>] git submodule update --remote

• Hexo theme spectre theme unexpected token error

• Hexo math not working

• Git – Resolve Merge Conflicts

  1 2	git checkout --ours PATH/FILE # accepting base version only git checkout --theirs PATH/FILE # accepting incoming version only

• How to use GitHub badges to stop feeling like a noob

• Katex can work more efficiently than Mathjax

Start PHP service:

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docker run --name phpfpm -d -v ~/www:/app php:5.6-fpm

Use a pre-built hexo image:

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docker run --name myhexo -v ~/blog:/root/blog -d sempr/hexo-al

Don’t forget to make links between containers:

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docker run -d --name mynginx -p 80:80 -p 443:443 --link phpfpm:phpfpm --link myhexo:myhexo -v ~/https.conf:/etc/nginx/conf.d/default.conf -v ~/1_im.semprathlon.net_bundle.crt:/etc/nginx/ssl/nginx.crt -v ~/2_im.semprathlon.net.key:/etc/nginx/ssl/nginx.key --volumes-from phpfpm nginx

Having trouble with Windows SSH: Unprotected private key file

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@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions for 'private' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
Load key "private": bad permissions

You can use icacls in windows instead of chmod to adjust file permission.

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icacls .\private.key /inheritance:r
icacls .\private.key /grant:r "%username%":"(R)"

Having trouble with SSH login: connection reset after idle for some time

[Ineffective]

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ssh -o TCPKeepAlive=true root@host.com

For long term use you should modify /etc/ssh/sshd_config as follows:

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ClientAliveInterval 30
ClientAliveCountMax 60

Error: Got permission denied while trying to connect to the Docker daemon socket

Follow the just a few steps and you do not have to access docker images with superuser privileges.

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sudo groupadd docker
sudo gpasswd -a ${USER} docker
sudo service docker restart

Add a new sudoer

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sudo usermod -aG sudo <username>