Use ListFunctions with an Amazon SDK or CLI

    /// <summary>
    /// Get a list of Lambda functions.
    /// </summary>
    /// <returns>A list of FunctionConfiguration objects.</returns>
    public async Task<List<FunctionConfiguration>> ListFunctionsAsync()
    {
        var functionList = new List<FunctionConfiguration>();

        var functionPaginator =
            _lambdaService.Paginators.ListFunctions(new ListFunctionsRequest());
        await foreach (var function in functionPaginator.Functions)
        {
            functionList.Add(function);
        }

        return functionList;
    }

        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

    std::vector<Aws::String> functions;
    Aws::String marker;

    do {
        Aws::Lambda::Model::ListFunctionsRequest request;
        if (!marker.empty()) {
            request.SetMarker(marker);
        }

        Aws::Lambda::Model::ListFunctionsOutcome outcome = client.ListFunctions(
                request);

        if (outcome.IsSuccess()) {
            const Aws::Lambda::Model::ListFunctionsResult &result = outcome.GetResult();
            std::cout << result.GetFunctions().size()
                      << " lambda functions were retrieved." << std::endl;

            for (const Aws::Lambda::Model::FunctionConfiguration &functionConfiguration: result.GetFunctions()) {
                functions.push_back(functionConfiguration.GetFunctionName());
                std::cout << functions.size() << "  "
                          << functionConfiguration.GetDescription() << std::endl;
                std::cout << "   "
                          << Aws::Lambda::Model::RuntimeMapper::GetNameForRuntime(
                                  functionConfiguration.GetRuntime()) << ": "
                          << functionConfiguration.GetHandler()
                          << std::endl;
            }
            marker = result.GetNextMarker();
        }
        else {
            std::cerr << "Error with Lambda::ListFunctions. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
    } while (!marker.empty());

To retrieve a list of Lambda functions

The following list-functions example displays a list of all of the functions for the current user.

aws lambda list-functions

Output:

{
    "Functions": [
        {
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "$LATEST",
            "CodeSha256": "dBG9m8SGdmlEjw/JYXlhhvCrAv5TxvXsbL/RMr0fT/I=",
            "FunctionName": "helloworld",
            "MemorySize": 128,
            "RevisionId": "1718e831-badf-4253-9518-d0644210af7b",
            "CodeSize": 294,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:helloworld",
            "Handler": "helloworld.handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-zgur6bf4",
            "Timeout": 3,
            "LastModified": "2023-09-23T18:32:33.857+0000",
            "Runtime": "nodejs18.x",
            "Description": ""
        },
        {
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "$LATEST",
            "CodeSha256": "sU0cJ2/hOZevwV/lTxCuQqK3gDZP3i8gUoqUUVRmY6E=",
            "FunctionName": "my-function",
            "VpcConfig": {
                "SubnetIds": [],
                "VpcId": "",
                "SecurityGroupIds": []
            },
            "MemorySize": 256,
            "RevisionId": "93017fc9-59cb-41dc-901b-4845ce4bf668",
            "CodeSize": 266,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
            "Handler": "index.handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/helloWorldPython-role-uy3l9qyq",
            "Timeout": 3,
            "LastModified": "2023-10-01T16:47:28.490+0000",
            "Runtime": "nodejs18.x",
            "Description": ""
        },
        {
            "Layers": [
                {
                    "CodeSize": 41784542,
                    "Arn": "arn:aws:lambda:us-west-2:420165488524:layer:AWSLambda-Python37-SciPy1x:2"
                },
                {
                    "CodeSize": 4121,
                    "Arn": "arn:aws:lambda:us-west-2:123456789012:layer:pythonLayer:1"
                }
            ],
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "$LATEST",
            "CodeSha256": "ZQukCqxtkqFgyF2cU41Avj99TKQ/hNihPtDtRcc08mI=",
            "FunctionName": "my-python-function",
            "VpcConfig": {
                "SubnetIds": [],
                "VpcId": "",
                "SecurityGroupIds": []
            },
            "MemorySize": 128,
            "RevisionId": "80b4eabc-acf7-4ea8-919a-e874c213707d",
            "CodeSize": 299,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-python-function",
            "Handler": "lambda_function.lambda_handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/my-python-function-role-z5g7dr6n",
            "Timeout": 3,
            "LastModified": "2023-10-01T19:40:41.643+0000",
            "Runtime": "python3.11",
            "Description": ""
        }
    ]
}

For more information, see Amazon Lambda Function Configuration in the Amazon Lambda Developer Guide.

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// ListFunctions lists up to maxItems functions for the account. This function uses a
// lambda.ListFunctionsPaginator to paginate the results.
func (wrapper FunctionWrapper) ListFunctions(ctx context.Context, maxItems int) []types.FunctionConfiguration {
	var functions []types.FunctionConfiguration
	paginator := lambda.NewListFunctionsPaginator(wrapper.LambdaClient, &lambda.ListFunctionsInput{
		MaxItems: aws.Int32(int32(maxItems)),
	})
	for paginator.HasMorePages() && len(functions) < maxItems {
		pageOutput, err := paginator.NextPage(ctx)
		if err != nil {
			log.Panicf("Couldn't list functions for your account. Here's why: %v\n", err)
		}
		functions = append(functions, pageOutput.Functions...)
	}
	return functions
}

const listFunctions = () => {
  const client = new LambdaClient({});
  const command = new ListFunctionsCommand({});

  return client.send(command);
};

    public function listFunctions($maxItems = 50, $marker = null)
    {
        if (is_null($marker)) {
            return $this->lambdaClient->listFunctions([
                'MaxItems' => $maxItems,
            ]);
        }

        return $this->lambdaClient->listFunctions([
            'Marker' => $marker,
            'MaxItems' => $maxItems,
        ]);
    }

Example 1: This sample displays all the Lambda functions with sorted code size

Get-LMFunctionList | Sort-Object -Property CodeSize | Select-Object FunctionName, RunTime, Timeout, CodeSize

Output:

FunctionName                                                 Runtime   Timeout CodeSize
------------                                                 -------   ------- --------
test                                                         python2.7       3      243
MylambdaFunction123                                          python3.8     600      659
myfuncpython1                                                python3.8     303      675

class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def list_functions(self):
        """
        Lists the Lambda functions for the current account.
        """
        try:
            func_paginator = self.lambda_client.get_paginator("list_functions")
            for func_page in func_paginator.paginate():
                for func in func_page["Functions"]:
                    print(func["FunctionName"])
                    desc = func.get("Description")
                    if desc:
                        print(f"\t{desc}")
                    print(f"\t{func['Runtime']}: {func['Handler']}")
        except ClientError as err:
            logger.error(
                "Couldn't list functions. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Lists the Lambda functions for the current account.
  def list_functions
    functions = []
    @lambda_client.list_functions.each do |response|
      response['functions'].each do |function|
        functions.append(function['function_name'])
      end
    end
    functions
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error listing functions:\n #{e.message}")
  end

    /** List all Lambda functions in the current Region. */
    pub async fn list_functions(&self) -> Result<ListFunctionsOutput, anyhow::Error> {
        info!("Listing lambda functions");
        self.lambda_client
            .list_functions()
            .send()
            .await
            .map_err(anyhow::Error::from)
    }

    TRY.
        oo_result =  lo_lmd->listfunctions( ).       " oo_result is returned for testing purposes. "
        DATA(lt_functions) = oo_result->get_functions( ).
        MESSAGE 'Retrieved list of Lambda functions.' TYPE 'I'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.