hostfile

#!/bin/bash

HOSTS_FILE="/etc/hosts"

# Usage
show_help() {
    echo "Usage:"
    echo "  hostfile <IP> <DOMAIN> [ADDITIONAL_DOMAINS...]"
    echo "  hostfile -R <DOMAIN>  (Remove entry for domain)"
    echo "  hostfile -h | --h | --help  (Show this help message)"
    exit 0
}

# at least one argument is provided
if [ "$#" -lt 1 ]; then
    show_help
fi

# display help
if [[ "$1" == "-h" || "$1" == "--h" || "$1" == "--help" ]]; then
    show_help
fi

# removal mode
if [ "$1" == "-R" ]; then
    if [ -z "$2" ]; then
        echo "Usage: hostfile -R <DOMAIN>"
        exit 1
    fi

    DOMAIN_TO_REMOVE="$2"

    # Ensure sudo is used to modify /etc/hosts
    sudo sed -i "/\s$DOMAIN_TO_REMOVE$/d" "$HOSTS_FILE"
    echo "Removed entry for $DOMAIN_TO_REMOVE from $HOSTS_FILE"
    exit 0
fi

# addition mode
IP="$1"
shift  # Remove IP from arguments list

# remove the existing entries from provided domains
for DOMAIN in "$@"; do
    # Ensure sudo is used to modify /etc/hosts
    sudo sed -i "/\s$DOMAIN$/d" "$HOSTS_FILE"
done

# append new entries
echo "$IP $*" | sudo tee -a "$HOSTS_FILE" > /dev/null

echo "Updated $HOSTS_FILE with: $IP $*"