This bash script will back up all the files in the current directory to a .tar.gz file. 

backup.sh

#!/bin/bash 
# This script will back up all the files in the current directory to a .tar.gz file. 
# Get the current date and time. 

date +"%Y-%m-%d_%H:%M:%S" 

# Create a backup file. 
backup_file="backup_$(date +"%Y-%m-%d_%H:%M:%S").tar.gz" 

# Tar up all of the files in the current directory. 
tar -czvf $backup_file * 

# Print a success message. 
echo "Backup complete!"