# getIps.sh

A bash script that resolves hostnames to their IPv4 and IPv6 addresses using DNS lookups.

## Description

This script reads a list of hostnames from an input file and performs DNS lookups to find their corresponding IPv4 and IPv6 addresses. The results are written to an output file in a tab-separated format.

## Usage

```bash
./getIps.sh <input_file> <output_file>
```

### Arguments

- `input_file`: Path to a text file containing hostnames (one per line)
- `output_file`: Path where the results will be written

### Example

```bash
./getIps.sh hosts.txt results.txt
```

## Input Format

The input file should contain hostnames, one per line:

```
google.com
github.com
stackoverflow.com
```

## Output Format

The output file will contain tab-separated values with the following columns:

```
hostname    IPv4_address    IPv6_address
```

Example output:
```
google.com    142.250.191.14    2a00:1450:4001:80e::200e
github.com    140.82.112.4      N/A
stackoverflow.com    151.101.1.69    N/A
```

## Features

- Resolves both IPv4 (A records) and IPv6 (AAAA records) addresses
- Handles empty lines in input file gracefully
- Shows "N/A" for addresses that cannot be resolved
- Clears previous output file before writing new results
- Provides usage information if incorrect arguments are provided

## Requirements

- `dig` command (part of dnsutils package)
- Bash shell

## Installation

Make the script executable:

```bash
chmod +x getIps.sh
```

## Error Handling

- The script will exit with an error if the wrong number of arguments is provided
- Empty lines in the input file are automatically skipped
- DNS resolution failures are handled gracefully (shows "N/A")