Describes the Regions for your account using an Amazon SDK

    Aws::EC2::EC2Client ec2Client(clientConfiguration);

    Aws::EC2::Model::DescribeRegionsRequest request;
    auto outcome = ec2Client.DescribeRegions(request);
    bool result = true;
    if (outcome.IsSuccess()) {
        std::cout << std::left <<
                  std::setw(32) << "RegionName" <<
                  std::setw(64) << "Endpoint" << std::endl;

        const auto &regions = outcome.GetResult().GetRegions();
        for (const auto &region: regions) {
            std::cout << std::left <<
                      std::setw(32) << region.GetRegionName() <<
                      std::setw(64) << region.GetEndpoint() << std::endl;
        }
    }
    else {
        std::cerr << "Failed to describe regions:" <<
                  outcome.GetError().GetMessage() << std::endl;
        result = false;
    }

import { DescribeRegionsCommand } from "@aws-sdk/client-ec2";

import { client } from "../libs/client.js";

export const main = async () => {
  const command = new DescribeRegionsCommand({
    // By default this command will not show regions that require you to opt-in.
    // When AllRegions true even the regions that require opt-in will be returned.
    AllRegions: true,
    // You can omit the Filters property if you want to get all regions.
    Filters: [
      {
        Name: "region-name",
        // You can specify multiple values for a filter.
        // You can also use '*' as a wildcard. This will return all
        // of the regions that start with `us-east-`.
        Values: ["ap-southeast-4"],
      },
    ],
  });

  try {
    const { Regions } = await client.send(command);
    const regionsList = Regions.map((reg) => ` • ${reg.RegionName}`);
    console.log("Found regions:");
    console.log(regionsList.join("\n"));
  } catch (err) {
    console.error(err);
  }
};

require "aws-sdk-ec2"

# @param ec2_client [Aws::EC2::Client] An initialized EC2 client.
# @example
#   list_regions_endpoints(Aws::EC2::Client.new(region: 'us-west-2'))
def list_regions_endpoints(ec2_client)
  result = ec2_client.describe_regions
  # Enable pretty printing.
  max_region_string_length = 16
  max_endpoint_string_length = 33
  # Print header.
  print "Region"
  print " " * (max_region_string_length - "Region".length)
  print "  Endpoint\n"
  print "-" * max_region_string_length
  print "  "
  print "-" * max_endpoint_string_length
  print "\n"
  # Print Regions and their endpoints.
  result.regions.each do |region|
    print region.region_name.to_s
    print " " * (max_region_string_length - region.region_name.length)
    print "  "
    print region.endpoint.to_s
    print "\n"
  end
end

# Displays a list of Amazon Elastic Compute Cloud (Amazon EC2)
# Availability Zones available to you depending on the AWS Region
# of the Amazon EC2 client.
#
# @param ec2_client [Aws::EC2::Client] An initialized EC2 client.
# @example
#   list_availability_zones(Aws::EC2::Client.new(region: 'us-west-2'))
def list_availability_zones(ec2_client)
  result = ec2_client.describe_availability_zones
  # Enable pretty printing.
  max_region_string_length = 16
  max_zone_string_length = 18
  max_state_string_length = 9
  # Print header.
  print "Region"
  print " " * (max_region_string_length - "Region".length)
  print "  Zone"
  print " " * (max_zone_string_length - "Zone".length)
  print "  State\n"
  print "-" * max_region_string_length
  print "  "
  print "-" * max_zone_string_length
  print "  "
  print "-" * max_state_string_length
  print "\n"
  # Print Regions, Availability Zones, and their states.
  result.availability_zones.each do |zone|
    print zone.region_name
    print " " * (max_region_string_length - zone.region_name.length)
    print "  "
    print zone.zone_name
    print " " * (max_zone_string_length - zone.zone_name.length)
    print "  "
    print zone.state
    # Print any messages for this Availability Zone.
    if zone.messages.count.positive?
      print "\n"
      puts "  Messages for this zone:"
      zone.messages.each do |message|
        print "    #{message.message}\n"
      end
    end
    print "\n"
  end
end

# Full example call:
def run_me
  region = ""
  # Print usage information and then stop.
  if ARGV[0] == "--help" || ARGV[0] == "-h"
    puts "Usage:   ruby ec2-ruby-example-regions-availability-zones.rb REGION"
    # Replace us-west-2 with the AWS Region you're using for Amazon EC2.
    puts "Example: ruby ec2-ruby-example-regions-availability-zones.rb us-west-2"
    exit 1
  # If no values are specified at the command prompt, use these default values.
  # Replace us-west-2 with the AWS Region you're using for Amazon EC2.
  elsif ARGV.count.zero?
    region = "us-west-2"
  # Otherwise, use the values as specified at the command prompt.
  else
    region = ARGV[0]
  end

  ec2_client = Aws::EC2::Client.new(region: region)

  puts "AWS Regions for Amazon EC2 that are available to you:"
  list_regions_endpoints(ec2_client)
  puts "\n\nAmazon EC2 Availability Zones that are available to you for AWS Region '#{region}':"
  list_availability_zones(ec2_client)
end

run_me if $PROGRAM_NAME == __FILE__

async fn show_regions(client: &Client) -> Result<(), Error> {
    let rsp = client.describe_regions().send().await?;

    println!("Regions:");
    for region in rsp.regions().unwrap_or_default() {
        println!("  {}", region.region_name().unwrap());
    }

    Ok(())
}

    TRY.
        oo_result = lo_ec2->describeregions( ) .                        " oo_result is returned for testing purposes. "
        DATA(lt_regions) = oo_result->get_regions( ).
        MESSAGE 'Retrieved information about Regions.' TYPE 'I'.
      CATCH /aws1/cx_rt_service_generic INTO DATA(lo_exception).
        DATA(lv_error) = |"{ lo_exception->av_err_code }" - { lo_exception->av_err_msg }|.
        MESSAGE lv_error TYPE 'E'.
    ENDTRY.