My-Various-Cheatsheets

Spring

Run an application (Spring boot should be installed)

mvn spring-boot:run

Build JAR/WAR package

mvn clean package

Start Tomcat (Apache Tomcat7 Maven Plugin required)

mvn tomcat7:run

JAVA

Generic way of overriding Object.toString() method (thank you org.apache.commons.lang3)

@Override
public String toString() {
    return ToStringBuilder.reflectionToString(this, ToStringStyle.SHORT_PREFIX_STYLE);
}

Call plsql procedure from java with JPA

@PersistenceContext
private EntityManager entityManager;

public String myfunc(final String param) {
    StoredProcedureQuery query = entityManager.createStoredProcedureQuery("plsql_procedure_name")
            .registerStoredProcedureParameter("param", String.class, ParameterMode.IN)
            .registerStoredProcedureParameter("result", String.class, ParameterMode.OUT)
            .setParameter("param", param);

    query.execute();

    return (String) query.getOutputParameterValue("result");

}

JS/TS/Node

JS

• ES6 Overview in 350 Bullet Points

• Will evaluate to true if aVariable is not : null, undefined, NaN, "", 0, false.

    if( aVariable ) {
     // Stuff
    }
  

Node

Get the current global prefix

npm prefix -g

NestJs

File uploading

  @Post('upload')
  @UseInterceptors(FileInterceptor('file',
    {
      storage: diskStorage({
        destination: './uploads', // be sure to create a .gitignore that ignores everything in the folder (except itself)

        filename: (req, file, cb) => {
          const randomName = Array(32).fill(null).map(() => (Math.round(Math.random() * 16)).toString(16)).join('')
          return cb(null, `${file.originalname}`)
        }
      })
    }
  ))
  async upload(@UploadedFile() file: BufferedFile) { // BufferedFile is an interface defined in the project
    await this.fileService.upload(file);
  }

NestJs pipeline digram (by demisx on stackoverflow) :

MAVEN

settings.xml file location (Debian based distros)

/usr/share/maven/conf

Skip maven tests when packaging

mvn package -DskipTests

Put a jar in the local repository

   mvn install:install-file
  -Dfile=<path-to-file>
  -DgroupId=<group-id>
  -DartifactId=<artifact-id>
  -Dversion=<version>
  -Dpackaging=<packaging>
  -DgeneratePom=true
 
Where: <path-to-file>  the path to the file to load
       <group-id>      the group that the file should be registered under
       <artifact-id>   the artifact name for the file
       <version>       the version of the file
       <packaging>     the packaging of the file e.g. jar

Symfony (2.7)

Create an admin user

php app/console fos:user:create admin [email protected] admin

NPM (3.9.2)

Install a npm module and save it to package.json

npm install <module_name> --save

Linux

Do nothing when the lid is closed (useful when using a laptop as a server)

# Content of /etc/systemd/logind.conf
[Login]
HandleLidSwitch=ignore

List all systemd services (grepable)

# systemctl list-units --type=service --state=active
OR
# systemctl --type=service --state=active

Copy a file over SSH

ssh-copy-id -i <file_path> <user@host>

Ping a specific port

nc -vz {host} {port}

Copy Content of a folder to another folder src

cp -a /source/. /dest/

Delete the content of a folder

 rm -rfv folder/*

copy folder

cp -ar source destination/ # -a preseves ownership -r for recursivity

Arch Linux (and derivatives)

Clean the package cache (to save space)

sudo pacman -Sc

Reinstall grub2 (may work on other distributions)

sudo grub-install --recheck --root-directory=/mnt /dev/sda\n
sudo grub-mkconfig -o /mnt/boot/grub/grub.cfg

Remove a desktop environement (kde)

pacman -Rnsc kde
sudo pacman -Rnsc kde-applications # To remove the DE associated apps

Force quit pacman/yaourt

sudo rm /var/lib/pacman/db.lck

How to setup mount / auto-mount USB Hard Drive / Alternative (tested on my Rpi 4B)

Check port status for a specific host

nmap <IP> -p <PORT>

Red Hat (based) distros

go to the internetz ! (uses /!\ Google Public DNS /!)

• Spot the disconnected network interface with nmcli.
• Then edit the right config file sudo vi /etc/sysconfig/network-scripts/ifcfg-<interface-name> by changing ONBOOT=no to ONBOOT=yes*
• Restart the network service sudo systemctl restart network.service
• Test ping google.com

Jekyll

• Any file whose name starts with _ is not imported into the _site folder after "compiling".

PostgreSQL

Connect to a database

psql <dbName> <userName>

Dumping a schema

pg_dump -h localhost -U user_name -s db_name > my_dump.sql

List all reserved words

select * from pg_get_keywords()

Changing the default Schema of a datatabase

-- Use this to show the current search_path
-- Should return: "$user",public
SHOW search_path;

-- Create another schema
CREATE SCHEMA my_schema;
GRANT ALL ON SCHEMA my_schema TO my_user;

-- To change search_path on a connection-level
SET search_path TO my_schema;

-- To change search_path on a database-level
ALTER database "my_database" SET search_path TO my_schema;
--src : https://wiki.hackzine.org/sysadmin/postgresql-change-default-schema.html

Restart postgres service on Windows

net stop postgresql-x64-14 && net start postgresql-x64-14

List all materialized views in postgres

SELECT relname FROM pg_catalog.pg_class WHERE relkind = 'm';

Git

Reverse git log

git log --reverse

Change git default editor

git config --global core.editor <editor>

Modify last commit

git commit --amend

Create a .gitignore on windows (create the gitignore.txt file before)

ren gitignore.txt .gitignore

Difference between --mixed, --soft, --hard reset (click on image to see source):

A very good GIT Cheatsheet

Change git remote URL (for remote repository migration)

git remote set-url origin git://new.url.here

Add multiple remotes (to push to both a gitlab and a github server for example)

git remote set-url origin --push --add <a remote>
git remote set-url origin --push --add <another remote>

Fast forwarding

Ignoring a file locally

git update-index --skip-worktree path/to/file

# Confirm
git ls-files -v | grep ^S

# Restore
git update-index --no-skip-worktree path/to/file

Global settings for line endings

$ git config --global core.autocrlf true

Squashing

• https://medium.com/@slamflipstrom/a-beginners-guide-to-squashing-commits-with-git-rebase-8185cf6e62ec

Cleaning untracked files

# Perform a “dry run” and show you what files and directories will be deleted
git clean -d -n

# Actual cleaning
git clean -d -f

Reset creds

git config --system --unset credential.helper

VIM

# Change color scheme (to elflord in this example) on the fly
:colorscheme elflord

# Display line numbers
:set number

# Delete current line
dd # or D

# Delete a single word
dw

# Delete all content
%d

Bash / Linux

LeCoupa's BASH Cheatsheet

Windows Commands

Find the process using a specific port (8080)

netstat -a -n -o | find "8080"

Get the name of a process from its PID

tasklist /fi "pid eq 21385"

Kill a process by its PID (2728)

taskkill /F /PID 2728

Display the command line with which the process is launched

wmic process where processid=<pid> get commandline

List mounted drives

df -aTh

LaTeX

A good looking listing configuration

 \lstset{aboveskip=20pt}
 
 \begin{lstlisting}[firstnumber=1,numbers=left,numberstyle=\bf \tiny \color{black},caption={Hello World},language=pascal,frame=lines]
    CODE HERE ...
\end{lstlisting}

RegExp

Select all the lines containing "hello"

^.*hello.*\r\n

WireShark

http contains "text" or http.response.code == 200

Tomcat

Undeploy an app via tomcat manager

curl -u user:pwd  "http://localhost:port/manager/text/undeploy?path=/myappspath/&version=myappsversion"

Intellij

Usual Intellij problems and how to resolve them

Error:java: javacTask: source release 8 requires target release 1.8

Reimporting all maven projects resolves this (CTRL+SHIFT+A then search for reimport).

Docker

• docker-compose.yml describes a docker based application (could use different containers).

Docker interactive mode

docker container run -ti ubuntu bash

Miscellaneous

• Music for programming - https://musicforprogramming.net
• ⚠️ https://github.com/sangimed/Coding-rules ⚠️