name="John"
echo ${name}
echo ${name/J/j}    #=> "john" (substitution)
echo ${name:0:2}    #=> "Jo" (slicing)
echo ${name::2}     #=> "Jo" (slicing)
echo ${name::-1}    #=> "Joh" (slicing)
echo ${name:(-1)}   #=> "n" (slicing from right)
echo ${name:(-2):1} #=> "h" (slicing from right)
echo ${food:-Cake}  #=> $food or "Cake"

touch /tmp/login1.txt /tmp/login2.txt
while [ true ]
do
	who | gawk '{ print $1 }' > /tmp/login2.txt
	comm -13 /tmp/login1.txt /tmp/login2.txt

	#Just a bit easier to read

	#diff /tmp/login1.txt /tmp/login2.txt
	cat /tmp/login2.txt > /tmp/login1.txt
	sleep 1
done

#!/bin/bash

git status

echo "Do you want to add all changed files?"
select yn in "Yes" "No"; do
        case $yn in
                Yes ) break;;
                No ) exit 1;;
        esac
done

git add -u

git status

echo "Does this look right?"
select yn in "Yes" "No"; do
        case $yn in
                Yes ) break;;
                No ) exit 2;;
        esac
done

git commit

echo "Do you want to push?"
select yn in "Yes" "No"; do
        case $yn in
                Yes ) break;;
                No ) exit 2;;
        esac
done

git push

#!/bin/bash
#  RCLONE BACKUP SCRIPT (using ionice)
#  Type crontab -e and copy the line below without the #
#  0 0 * * * ionice -c 3 /home/owner/backup.sh >/dev/null 2>&1 
nowdate=$(date -u)

# OPTIONS
WEBHOOK="YOUR_DISCORD_WEBHOOK_LINK_HERE"
LOGFILE="/root/backup.log"
FROM="/path/where/you/backup/from"
TO="backblaze:BucketName/FolderName"
SERVERNAME="Server Name"

echo "$SERVERNAME started a backup - $nowdate" | tee -a $LOGFILE
curl --data "content=$SERVERNAME started a backup - $nowdate" $WEBHOOK | tee -a $LOGFILE && echo "" >> $LOGFILE

if pidof -o %PPID -x "backup.sh"
then
        echo "Failed backup attempt on $SERVERNAME - $nowdate (rclone already running)" | tee -a $LOGFILE
        curl --data "content=Failed backup attempt on $SERVERNAME - $nowdate (rclone already running)" $WEBHOOK | tee -a $LOGFILE
        exit 1
fi

rclone sync $FROM $TO -P --b2-hard-delete --stats 5s --progress | sed 's/Transferred:/\n\nTransferred:/' | tee -a $LOGFILE

enddate=$(date -u)
endtime=$(date +'%T')
echo "Completed backup on $SERVERNAME - $enddate" | tee -a $LOGFILE
curl -F "content=Completed backup on $SERVERNAME - $enddate" -F upload=@"$LOGFILE" $WEBHOOK | tee -a $LOGFILE

if [ -f $LOGFILE ]
then
        rm $LOGFILE
fi

# ---------------- FIREWALL STEPS ----------------


# Check if firewalld is installed and running
sudo systemctl status firewalld


# If it's not running, you can start and enable it
sudo systemctl start firewalld
sudo systemctl enable firewalld


# Add a rule to allow traffic on port 6006. Port 6006 is the default port that storybook runs on.
sudo firewall-cmd --permanent --add-port=6006/tcp


# Reload the firewall for the changes to take effect
sudo firewall-cmd --reload


# Check the list of allowed ports
sudo firewall-cmd --list-ports


# ---------------- NGINX STEPS ----------------


# Install Nginx (if not already installed)
sudo yum install nginx


# Start and enable Nginx
sudo systemctl start nginx
sudo systemctl enable nginx


# Copy your storybook-static directory to a location that Nginx can serve from.

# The default web root directory for Nginx is /usr/share/nginx/html.
sudo cp -r /path/to/storybook-static /usr/share/nginx/html/


# Adjust file permissions if needed to ensure that Nginx can read the files
sudo chown -R nginx:nginx /usr/share/nginx/html/storybook-static


# Put the following server block in /etc/nginx/conf.d/storybook.conf
server {
    listen 6006;
    server_name your_domain.com;

    location / {
        root /usr/share/nginx/html/storybook-static;
        index index.html;
    }
}


# Test the Nginx configuration for syntax errors
sudo nginx -t


# If there are no errors, reload Nginx to apply the changes
sudo systemctl reload nginx

# Three ways of checking if a file exists in a shell script

FILE=/etc/resolv.conf

if test -f "$FILE"; then
    echo "$FILE exists."
fi

if [ -f "$FILE" ]; then
    echo "$FILE exists."
fi

if [[ -f "$FILE" ]]; then
    echo "$FILE exists."
fi