Sudo on Ubuntu without requiring a password

Using AWS EC2 Ubuntu as a reference. It has a file by the name...

/etc/sudoers.d/90-cloudimg-ubuntu

It has the following content. With this, the user ubuntu can run sudo without a password.

# User rules for ubuntu ubuntu ALL=(ALL) NOPASSWD:ALL

Secure Copy from Remote Directory

The format to use.

scp -r shortcut:/remote/server/path/file.tar.gz /target/path/

Example:

scp -r shortcut:/home/user/file.tar.gz ~/download

Systemd or SysVinit

Use the below command to find out which command you should use to manage your Linux services.

ps -p 1 -o comm=

You will either see init (SysVinit) or systemd.

Systemd command	SysVinit command
systemctl start service_name	service service_name start
systemctl stop service_name	service service_name stop
systemctl restart service_name	service service_name restart
systemctl status service_name	service service_name status
systemctl enable service_name	chkconfig service_name on
systemctl disable service_name	chkconfig service_name off

Useful git commands

List config.

git config --list
git config --list --local
git config --list --global
git config --list --system

Set global name and email.

git config --global user.name "Your Name"
git config --global user.email "youremail@yourdomain.com"

Check what's going on

git status

Check changes made to a file

git diff path/to/file

Stage changes

# Stage all
git add .
# Stage one file
git add path/to/file

Untage changes

# Stage all
git reset
# Stage one file
git reset path/to/file

Revert changes made to path/to/file

git checkout path/to/file

Revert all uncommited changes

git checkout .

Commit staged files

git commit -m "Put a message here."

Check commits that had not been pushed.

git log origin/main..main

Check history of path/to/file

git log -p -- path/to/file

Update directory or file permission recursively in Linux

Change directory permission in my_directory.

find my_directory -type d -exec chmod 755 {} \;

Change file permission in my_directory.

find my_directory -type f -exec chmod 644 {} \;

Remove duplicate lines in Visual Studio Code

Search and replace in Visual Studio Code.

Search for

^(.*)(\n\1)+$

Replace with

$1

MongoDB JSON to PHP array

Search and replace in Visual Studio Code.

Search for

\{\n.*\$oid.*"(.*)"\n.*\}

Replace with

new MongoDB\BSON\ObjectId("$1")

Search for

\{\n.*numberDouble.*"(.*)"\n.*\}

Replace with

$1

Search for

\{\n.*numberInt.*"(.*)"\n.*\}

Replace with

$1