lucwj

Find and update

db.distributedomains.find().snapshot().forEach(
    function (elem) {
        db.distributedomains.update(
            {
                _id: elem._id
            },
            {
 $set: {

lucwj

function formatBytes(bytes,decimals) {
   if(bytes == 0) return '0 Bytes';
   var k = 1000,
       dm = decimals || 2,
       sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
       i = Math.floor(Math.log(bytes) / Math.log(k));
   return parseFloat((bytes / Math.pow(k, i)).toFixed(dm)) + ' ' + sizes[i];
}

lucwj

Measuring execution time in Go

Simple timing in golang

Sometimes you just want to do some quick and dirty timing of a code segment. A simple way to time execution in Golang is to use the time.Now() and time.Since() functions:

func main() {
    start := time.Now()

    r := new(big.Int)

lucwj

Verify You Have a CUDA-Capable GPU

To verify that your GPU is CUDA-capable, go to your distribution's equivalent of System Properties, or, from the command line, enter:

lspci | grep -i nvidia

If you do not see any settings, update the PCI hardware database that Linux maintains by entering update-pciids (generally found in /sbin) at the command line and rerun the previous lspci command.

If your graphics card is from NVIDIA and it is listed in CUDA-GPUS, your GPU is CUDA-capable.

lucwj

export CUDA_HOME=/usr/local/cuda
export NVIDIA_HOME=/usr/local/nvidia
 
export PATH=${CUDA_HOME}/bin:${PATH}
export LD_LIBRARY_PATH=${CUDA_HOME}/lib64:${LD_LIBRARY_PATH}

lucwj

List all file with human readable size

ls -alh

List all extension in directory with file count

ls -R | egrep '(\.\w+)$' -o | sort | uniq -c | sort -r

Count total files in directory

ls -1 | wc -l

lucwj

# First install tmux
brew install tmux

# For mouse support (for switching panes and windows)
# Only needed if you are using Terminal.app (iTerm has mouse support)
Install http://www.culater.net/software/SIMBL/SIMBL.php
Then install https://bitheap.org/mouseterm/

# More on mouse support http://floriancrouzat.net/2010/07/run-tmux-with-mouse-support-in-mac-os-x-terminal-app/

lucwj

Learn NodeJS by building 10 projects

Project 1: Simple Web Server

Project 2: Basic Express Website

Project 3: User Login System

Project 4: Node Blog Systems

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Section 1: Introducton and Setup

• Web Mind Set
• Introduction and the Goal of this Course
• How to play together
• npm, yarn, git & some Command Line References
• Install NodeJS

Section 2: Playground

• Introduce about javascript ES6
• Anonymous function

lucwj

ssh-keygen -t rsa -b 4096 -f jwtRS256.key
# Don't add passphrase
openssl rsa -in jwtRS256.key -pubout -outform PEM -out jwtRS256.key.pub
cat jwtRS256.key
cat jwtRS256.key.pub