tricks.txt

There is a website built for cheatsheet https://devhints.io/, I may want to build one for myself.

# Node
# Easy way to update the node.js
	$ npm install -g n
	$ n stable
# npm global install location on OSX: /usr/local/share/npm
# Use taobao image to help speed up the npm install
	$ npm install --registry=https://registry.npm.taobao.org
# check the installed npm package version
	$ npm view <package name> version

# Short key for WebStorm
Alt+F12: internal terminal
Ctrl+shift+F10: Run the code
# Webstorm tricks
	# split edit view: right click the doc tab and choose split
# Find in Path
	ctrl+shift+F
# Replace all
	cmd + R

# Docker
# check images
	$ docker images
# check containers
	docker ps
	# -a means all, -l means the last run container
# rm docker image by image_id
	$ docker rmi <image_id>
# rm all docker containers
	$ docker rm -f $(docker ps -aq)
	# -f: force, -a: all, -q: quiet(only show the id part)
# speed up docker pull if u r in China: https://www.docker-cn.com/registry-mirror
	# example: just add registry.docker-cn.com before the image
	$ docker pull registry.docker-cn.com/library/ubuntu:16.04
	# If u r using ubuntu, to download from China image website for good, open /etc/default/docker and add a line at the end of the file
		DOCKER_OPTS="--registry-mirror=https://registry.docker-cn.com"
		# reboot the Docker service
		$ sudo service docker restart
# enter running docker container
	$ docker exec -it <name> /bin/bash
	# if there is no parameter -it during "docker run", we need use cmd above to enter the container
# read docker logs
	$ docker log -f
	$ docker logs <container name>
# remove
	# docker image
		$ docker rmi <image1> <image2>
	# docker container 
		$ docker rm <container>
	# all the currently-running containers:
		$ docker rm -f $(docker ps -aq)
	# docker volumes
		$ docker volume ls # check the list of volumes
		$ docker volume rm <volume_name>
# stop docker container
		$ docker container stop <docker container id>
# start the container
		$ docker start <docker container id>
		# diff from "docker run" which will build a new container every time, the docker start will only work on the existing one
		# for the running docker containe, restart
		$ docker restart <container id>
# rename the docker image
		$ docker tag oldrepo:tag newrepo:tag
		# remove the old name if u want
		$ docker rmi oldrepo
# check the logs
		$ docker logs -f <container id>
		# when docker is running the container and there is -it for entering the container, we need this command to check the output
# check the process in docker
		$ docker top <container id>
# Build the docker image
	# method 1: update the existing image	
		# First run a container based on the existing image
		$ docker run -t -i ubuntu:16.04 /bin/bash
		# Then run the update command inside the running container
		$ apt-get update
		# exit the container and commit the update version
		$ docker commit -m="some messge" -a="author name" <container id> repo:tag
	# method 2: build the docker image from the ground
		# basically we need a Dockerfile, check how to write a Dockerfile by yourself
# copy the file from a running Docker container to local host
		$ docker container cp <container ID>:</path/to/file>
# if something like "permission denied" in docker, add the current user to the docker group, log out and log back install
	sudo usermod -a -G docker $USER
# save docker image
	$ docker save -o <filename>.tar <image_name>:version
# load docker image
	$ docker load < <filename>.tar
# check all the containers whose image name contains <string> and just print out the container ID
	$ docker ps -a | awk '$2~/<string>/ {print $1}'
# check all the docker images whose repo starts with <string> and just print out the image ID
	docker images | grep "^<string>" | awk '{print $3}' 
# assign the work permission for work 
	$ sudo groupadd docker # add the docker group if it doesn't exist
	$ sudo gpasswd -a $USER docker # add the $USER to group
	$ systemctl restart docker $ restart the docker to activate the settin
# change the default setting for storing the docker image and container data
	config the /etc/docker/daemon.json or /usr/lib/systemd/system/docker.service fileg
# copy files from docker container to host
	docker cp <container ID>:/file/path/within/container /host/path

# Vim
# go to the end of file
	shift+g
# go to the beginning of the file
	press g twice
# move to the end of line
	$(the last empty), A(it's like $ + i), g_(jump to last non blank)
# move to the beginning
	^ or _(move to the first non-whitespace char in the line), | or 0(zero)(move a little bit ahead of ^ or _)
# to search a string
	/<target_string>
	# press n to go to next matched string, press N to go to the previous string
	# search from the end of the files
	?<target_string>
	# disable highlights at other files
	:noh
# comment multiple line at once
	# move the cursor to the first char of the first line in block code you want to comment and type "CTRL+V" to enter VISUAL BLOCK mode
		# CTRL+V
	# use down arrow button or j button to move the cursor down until you reach the last line of the code block
		# move cursor down
	# Then type the below key to enter INSERT mode
		# shift+I
	# type # or the character for commenting for the certain language
		# type #
	# click ESC and done
# check the fileformat
	$ set ff
# set the fileformat
	$ set ff=unix OR dos

# shell command
# delete all files in current directory and its sub-directories where the file name starts with "foo"
	$ find . -type f -name foo\* -exec rm {} \;
	$ grep -R -i "<foo>" *
# check the port being used
	$ sudo lsof -i tcp:<port number>
# to run the program at the background, first ctrl+z
	$ bg
	$ fg # put it front again and we can kill it by press ctrl+c
# to send a post request
	$ curl -i http://localhost:3000/users -d "name=test"
# change the environment variables for mac
	$ vim ~/.bash_profile
# change the file or directory role from root to work
	$ chown work: <filename or directory>
# pack the file using tar
	$ tar -zcvf <>.tar.gz <dir_name>/
# To unpack a tar file
	$ tar -xvzf filename.tar.gz
# send GET request to API
	$ curl <ip_address>:<port>/<api>
# change the usermode from root to work
	$ su - work
# command for secureCRT
	$ rz # upload file
	$ sz -e <filename> # download file
		# go to option/Session Option/\X/Y/Zmodem\ to configure the download path
# find which file include the string under this folder
	$ grep -nr '<string>*' .
# list all fiiles in the current directory staring with <string>
	$ find . -name <string>\*
# the previous command
	$ !! OR $ !-1
# the most recent input that starts with "mak"
	$ !mak
# use the last term from the previous input
	!$ # from 'ls /some/path', !$ = /home/path
# get the 2nd row, 2nd column from the command output
	$ <command> | sed -n '2p' | awk '{print $2}'
	# notes: it may be quite useful to kill the process. 'sed' and 'awk' are really useful in text manipulation.
	# example: kill the process which is using the port 1081
	$ kill $(lsof -i tcp:1081 | sed -n '2p' | awk '{print $2}')
# list the files w/ size under this directory
	$ ll --block-size=M
# count how much lines the file contains
	$ wc -l <filename>
# check the hostname
	$ hostname
# check whoami
	$ whoami
# check who is using the machine
	$ w
# check what they are doing
	$ top
# check the connection for certain port
	netstat -ant | grep -i "port"

# shell if statements
# check if the first arg is an empty string, where ! means 'not', -z meanns empty
	if [! -z $1]; then

# IntelliJ IDEA
1. To open any class in the editor quickly, press ⌘O (Navigate | Class) and start typing the name of the class. Choose the class from a drop-down list that appears.
2. The Code Completion feature lets you quickly complete different kinds of statements in the code. For example, start typing a class name and press ⌃Space to complete it. When multiple choices are available, they are shown in the lookup list.
3. To navigate to the declaration of a class, method or variable used somewhere in the code, position the caret at the usage and press ⌘B (Navigate | Declaration). You can also click the mouse on usages with the Ctrl key pressed to jump to declarations.
4. You can quickly navigate in the currently edited file with ⌘F12 (Navigate | File Structure).
It shows the list of members of the current class. Select an element you want to navigate to and press the Enter key or the ⌘↓ key.
To easily locate an item in the list, just start typing its name. 
# generate getters and setters quickly for JAVA
	right click and choose generate(OR cmd+N) ---> set getter and setter  ---> select member variables ---> click ok

# Linux system
# check the number of cpus
	$ lscpu
# test network connection: telnet
	$ telnet <address> <port>

# fabric
# add the chaincode project under gopath using soft link
	$ cd $GOPATH/src/github.com/hyperledger && ln - s <chaincode dir path>
# install the chaincode dependency
	$ cd $GOPATH/src/github.com/hyperledger/<chaincode dir path> && goverdor sync
# test the chaincode
	$ go test

# tools
## Node
### nrm to change the source