update ssh host

#!/bin/bash

# Prompt for the EC2 endpoint
echo "Please paste the EC2 endpoint:"
read EC2_ENDPOINT

# Check if the input looks like an EC2 endpoint
if [[ "$EC2_ENDPOINT" =~ ec2-[0-9-]+\.compute-[0-9]+\.amazonaws\.com ]]; then
    # Create a temporary file for the modified config
    TMP_FILE=$(mktemp)

    # Flag to track whether the 'calan' host has been found
    HOST_FOUND=0

    # Read .ssh/config line by line
    while IFS= read -r line
    do
        # Check for the host calan
        if [[ "$line" =~ "Host calan" ]]; then
            HOST_FOUND=1
            echo "$line" >> "$TMP_FILE"
        elif [[ "$HOST_FOUND" -eq 1 && "$line" =~ HostName ]]; then
            # Update the HostName line
            echo "    HostName $EC2_ENDPOINT" >> "$TMP_FILE"
            HOST_FOUND=0
        else
            # Copy the line as is
            echo "$line" >> "$TMP_FILE"
        fi
    done < ~/.ssh/config

    # Move the temporary file to the original config file location
    mv "$TMP_FILE" ~/.ssh/config
    echo "HostName updated to $EC2_ENDPOINT in .ssh/config"
    # Remove the temporary file if needed
    # rm "$TMP_FILE"
else
    echo "Error: The input does not contain a valid EC2 endpoint"
fi