Use ListSubscriptions with an Amazon SDK or command line tool

    using System;
    using System.Collections.Generic;
    using System.Threading.Tasks;
    using Amazon.SimpleNotificationService;
    using Amazon.SimpleNotificationService.Model;

    /// <summary>
    /// This example will retrieve a list of the existing Amazon Simple
    /// Notification Service (Amazon SNS) subscriptions.
    /// </summary>
    public class ListSubscriptions
    {
        public static async Task Main()
        {
            IAmazonSimpleNotificationService client = new AmazonSimpleNotificationServiceClient();

            Console.WriteLine("Enter a topic ARN to list subscriptions for a specific topic, " +
                              "or press Enter to list subscriptions for all topics.");
            var topicArn = Console.ReadLine();
            Console.WriteLine();

            var subscriptions = await GetSubscriptionsListAsync(client, topicArn);

            DisplaySubscriptionList(subscriptions);
        }

        /// <summary>
        /// Gets a list of the existing Amazon SNS subscriptions, optionally by specifying a topic ARN.
        /// </summary>
        /// <param name="client">The initialized Amazon SNS client object used
        /// to obtain the list of subscriptions.</param>
        /// <param name="topicArn">The optional ARN of a specific topic. Defaults to null.</param>
        /// <returns>A list containing information about each subscription.</returns>
        public static async Task<List<Subscription>> GetSubscriptionsListAsync(IAmazonSimpleNotificationService client, string topicArn = null)
        {
            var results = new List<Subscription>();

            if (!string.IsNullOrEmpty(topicArn))
            {
                var paginateByTopic = client.Paginators.ListSubscriptionsByTopic(
                    new ListSubscriptionsByTopicRequest()
                    {
                        TopicArn = topicArn,
                    });

                // Get the entire list using the paginator.
                await foreach (var subscription in paginateByTopic.Subscriptions)
                {
                    results.Add(subscription);
                }
            }
            else
            {
                var paginateAllSubscriptions = client.Paginators.ListSubscriptions(new ListSubscriptionsRequest());

                // Get the entire list using the paginator.
                await foreach (var subscription in paginateAllSubscriptions.Subscriptions)
                {
                    results.Add(subscription);
                }
            }

            return results;
        }

        /// <summary>
        /// Display a list of Amazon SNS subscription information.
        /// </summary>
        /// <param name="subscriptionList">A list containing details for existing
        /// Amazon SNS subscriptions.</param>
        public static void DisplaySubscriptionList(List<Subscription> subscriptionList)
        {
            foreach (var subscription in subscriptionList)
            {
                Console.WriteLine($"Owner: {subscription.Owner}");
                Console.WriteLine($"Subscription ARN: {subscription.SubscriptionArn}");
                Console.WriteLine($"Topic ARN: {subscription.TopicArn}");
                Console.WriteLine($"Endpoint: {subscription.Endpoint}");
                Console.WriteLine($"Protocol: {subscription.Protocol}");
                Console.WriteLine();
            }
        }
    }

//! Retrieve a list of Amazon Simple Notification Service (Amazon SNS) subscriptions.
/*!
  \param clientConfiguration: AWS client configuration.
  \return bool: Function succeeded.
 */
bool AwsDoc::SNS::listSubscriptions(
        const Aws::Client::ClientConfiguration &clientConfiguration) {
    Aws::SNS::SNSClient snsClient(clientConfiguration);

    Aws::String nextToken; // Next token is used to handle a paginated response.
    bool result = true;
    Aws::Vector<Aws::SNS::Model::Subscription> subscriptions;
    do {
        Aws::SNS::Model::ListSubscriptionsRequest request;

        if (!nextToken.empty()) {
            request.SetNextToken(nextToken);
        }

        const Aws::SNS::Model::ListSubscriptionsOutcome outcome = snsClient.ListSubscriptions(
                request);

        if (outcome.IsSuccess()) {
            const Aws::Vector<Aws::SNS::Model::Subscription> &newSubscriptions =
                    outcome.GetResult().GetSubscriptions();
            subscriptions.insert(subscriptions.cend(), newSubscriptions.begin(),
                                 newSubscriptions.end());
        }
        else {
            std::cerr << "Error listing subscriptions "
                      << outcome.GetError().GetMessage()
                      <<
                      std::endl;
            result = false;
            break;
        }

        nextToken = outcome.GetResult().GetNextToken();
    } while (!nextToken.empty());

    if (result) {
        if (subscriptions.empty()) {
            std::cout << "No subscriptions found" << std::endl;
        }
        else {
            std::cout << "Subscriptions list:" << std::endl;
            for (auto const &subscription: subscriptions) {
                std::cout << "  * " << subscription.GetSubscriptionArn() << std::endl;
            }
        }
    }
    return result;
}

To list your SNS subscriptions

The following list-subscriptions example displays a list of the SNS subscriptions in your Amazon account.

aws sns list-subscriptions

Output:

{
    "Subscriptions": [
        {
            "Owner": "123456789012",
            "Endpoint": "my-email@example.com",
            "Protocol": "email",
            "TopicArn": "arn:aws:sns:us-west-2:123456789012:my-topic",
            "SubscriptionArn": "arn:aws:sns:us-west-2:123456789012:my-topic:8a21d249-4329-4871-acc6-7be709c6ea7f"
        }
    ]
}

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.sns.SnsClient;
import software.amazon.awssdk.services.sns.model.ListSubscriptionsRequest;
import software.amazon.awssdk.services.sns.model.ListSubscriptionsResponse;
import software.amazon.awssdk.services.sns.model.SnsException;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class ListSubscriptions {
    public static void main(String[] args) {
        SnsClient snsClient = SnsClient.builder()
                .region(Region.US_EAST_1)
                .build();

        listSNSSubscriptions(snsClient);
        snsClient.close();
    }

    public static void listSNSSubscriptions(SnsClient snsClient) {
        try {
            ListSubscriptionsRequest request = ListSubscriptionsRequest.builder()
                    .build();

            ListSubscriptionsResponse result = snsClient.listSubscriptions(request);
            System.out.println(result.subscriptions());

        } catch (SnsException e) {

            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
}

Create the client in a separate module and export it.

import { SNSClient } from "@aws-sdk/client-sns";

// The AWS Region can be provided here using the `region` property. If you leave it blank
// the SDK will default to the region set in your AWS config.
export const snsClient = new SNSClient({});

Import the SDK and client modules and call the API.

import { ListSubscriptionsByTopicCommand } from "@aws-sdk/client-sns";
import { snsClient } from "../libs/snsClient.js";

/**
 * @param {string} topicArn - The ARN of the topic for which you wish to list subscriptions.
 */
export const listSubscriptionsByTopic = async (topicArn = "TOPIC_ARN") => {
  const response = await snsClient.send(
    new ListSubscriptionsByTopicCommand({ TopicArn: topicArn }),
  );

  console.log(response);
  // {
  //   '$metadata': {
  //     httpStatusCode: 200,
  //     requestId: '0934fedf-0c4b-572e-9ed2-a3e38fadb0c8',
  //     extendedRequestId: undefined,
  //     cfId: undefined,
  //     attempts: 1,
  //     totalRetryDelay: 0
  //   },
  //   Subscriptions: [
  //     {
  //       SubscriptionArn: 'PendingConfirmation',
  //       Owner: '901487484989',
  //       Protocol: 'email',
  //       Endpoint: 'corepyle@amazon.com',
  //       TopicArn: 'arn:aws:sns:us-east-1:901487484989:mytopic'
  //     }
  //   ]
  // }
  return response;
};

suspend fun listSNSSubscriptions() {

    SnsClient { region = "us-east-1" }.use { snsClient ->
        val response = snsClient.listSubscriptions(ListSubscriptionsRequest {})
        response.subscriptions?.forEach { sub ->
            println("Sub ARN is ${sub.subscriptionArn}")
            println("Sub protocol is ${sub.protocol}")
        }
    }
}

require 'vendor/autoload.php';

use Aws\Exception\AwsException;
use Aws\Sns\SnsClient;


/**
 * Returns a list of Amazon SNS subscriptions in the requested region.
 *
 * This code expects that you have AWS credentials set up per:
 * https://docs.aws.amazon.com/sdk-for-php/v3/developer-guide/guide_credentials.html
 */

$SnSclient = new SnsClient([
    'profile' => 'default',
    'region' => 'us-east-1',
    'version' => '2010-03-31'
]);

try {
    $result = $SnSclient->listSubscriptions();
    var_dump($result);
} catch (AwsException $e) {
    // output error message if fails
    error_log($e->getMessage());
}

class SnsWrapper:
    """Encapsulates Amazon SNS topic and subscription functions."""

    def __init__(self, sns_resource):
        """
        :param sns_resource: A Boto3 Amazon SNS resource.
        """
        self.sns_resource = sns_resource


    def list_subscriptions(self, topic=None):
        """
        Lists subscriptions for the current account, optionally limited to a
        specific topic.

        :param topic: When specified, only subscriptions to this topic are returned.
        :return: An iterator that yields the subscriptions.
        """
        try:
            if topic is None:
                subs_iter = self.sns_resource.subscriptions.all()
            else:
                subs_iter = topic.subscriptions.all()
            logger.info("Got subscriptions.")
        except ClientError:
            logger.exception("Couldn't get subscriptions.")
            raise
        else:
            return subs_iter

# This class demonstrates how to list subscriptions to an Amazon Simple Notification Service (SNS) topic
class SnsSubscriptionLister
  def initialize(sns_client)
    @sns_client = sns_client
    @logger = Logger.new($stdout)
  end

  # Lists subscriptions for a given SNS topic
  # @param topic_arn [String] The ARN of the SNS topic
  # @return [Types::ListSubscriptionsResponse] subscriptions: The response object
  def list_subscriptions(topic_arn)
    @logger.info("Listing subscriptions for topic: #{topic_arn}")
    subscriptions = @sns_client.list_subscriptions_by_topic(topic_arn: topic_arn)
    subscriptions.subscriptions.each do |subscription|
      @logger.info("Subscription endpoint: #{subscription.endpoint}")
    end
    subscriptions
  rescue Aws::SNS::Errors::ServiceError => e
    @logger.error("Error listing subscriptions: #{e.message}")
    raise
  end
end

# Example usage:
if $PROGRAM_NAME == __FILE__
  sns_client = Aws::SNS::Client.new
  topic_arn = "SNS_TOPIC_ARN" # Replace with your SNS topic ARN
  lister = SnsSubscriptionLister.new(sns_client)

  begin
    lister.list_subscriptions(topic_arn)
  rescue StandardError => e
    puts "Failed to list subscriptions: #{e.message}"
    exit 1
  end
end

    TRY.
        oo_result = lo_sns->listsubscriptions( ).                " oo_result is returned for testing purposes. "
        DATA(lt_subscriptions) = oo_result->get_subscriptions( ).
        MESSAGE 'Retrieved list of subscribers.' TYPE 'I'.
      CATCH /aws1/cx_rt_generic.
        MESSAGE 'Unable to list subscribers.' TYPE 'E'.
    ENDTRY.