dartokloning / UsernameValidation.sh

#!/bin/bash #Validation Function: #- Checks if the username is not empty and has at least 5 characters. #- Checks if the username contains only letters and numbers with no spaces. #- Checks if the username already exists on the system. #Input and Validation: #- Prompts the user to enter a username. #- Calls the validation function to check the entered username. #- Displays appropriate messages based on the validation result. # Function to validate the username function validate_username() { local username="$1" # Check if username is not empty and has at least 5 characters if [[ -z "$username" ]] || [[ ${#username} -lt 5 ]]; then echo "Username must be at least 5 characters long and cannot be empty." return 1 fi # Check if username contains only lowercase letters and numbers if ! [[ "$username" =~ ^[a-z0-9]+$ ]]; then echo "Username can only contain lowercase letters and numbers, and no spaces." return 1 fi # Check if the username already exists on the system if id "$username" &>/dev/null; then echo "Username already exists on the system." return 1 fi return 0 } # Get username input from the user read -p "Enter username: " username # Validate the username if validate_username "$username"; then echo "Username is valid." else echo "Username is invalid. Please try again." fi