From cc6e3309c6ae7932102f51381b91dece371b265f Mon Sep 17 00:00:00 2001
From: TwistedTwigleg <ncbeard@amazon.com>
Date: Mon, 14 Mar 2022 19:11:36 -0400
Subject: [PATCH] Refactor of command line argument parsing to single file
 (#388)

Now command line parsing is broken down into a shared module so
it can be reused across samples. This makes samples smaller and
reduces bloat.

Commit log:
* Initial work on simplifying command line parsing
* Continued work on simplifying command line parsing
* Reformatted samples with, hopefully, the correct clang format setting this times
* Another attempt at fixing clang format issues
* Adjustments to CommandLineUtils and samples to allow building on Windows and Linux
* Adjusted secure_tunnel sample to use AWS String instead of std string
* Remove commented out namespace usage in secure_tunnel sample
* Adjusted samples command line parser to show input type for commands
* Minor command line parsing format fixes
* Adjusted based on review feedback
* Minor formatting fix
* Removed const in main function in samples
* Clang format fixes
* Added additional command groups
* Renamed AddCommonX509Commands utility function
---
 .../greengrass/basic_discovery/CMakeLists.txt |   2 +
 samples/greengrass/basic_discovery/main.cpp   | 109 +++------
 samples/greengrass/ipc/CMakeLists.txt         |   2 +
 samples/greengrass/ipc/main.cpp               |  47 +---
 .../fleet_provisioning/CMakeLists.txt         |   2 +
 samples/identity/fleet_provisioning/main.cpp  |  78 ++----
 .../describe_job_execution/CMakeLists.txt     |   2 +
 samples/jobs/describe_job_execution/main.cpp  |  70 ++----
 samples/mqtt/basic_pub_sub/CMakeLists.txt     |   2 +
 samples/mqtt/basic_pub_sub/main.cpp           | 229 +++++-------------
 samples/mqtt/pkcs11_pub_sub/CMakeLists.txt    |   2 +
 samples/mqtt/pkcs11_pub_sub/main.cpp          | 138 +++--------
 samples/mqtt/raw_pub_sub/CMakeLists.txt       |   2 +
 samples/mqtt/raw_pub_sub/main.cpp             | 145 ++++-------
 .../secure_tunnel/CMakeLists.txt              |   2 +
 .../secure_tunneling/secure_tunnel/main.cpp   | 177 +++++---------
 .../tunnel_notification/CMakeLists.txt        |   2 +
 .../tunnel_notification/main.cpp              |  65 ++---
 samples/shadow/shadow_sync/CMakeLists.txt     |   2 +
 samples/shadow/shadow_sync/main.cpp           |  70 ++----
 samples/utils/CommandLineUtils.cpp            | 174 +++++++++++++
 samples/utils/CommandLineUtils.h              | 164 +++++++++++++
 22 files changed, 675 insertions(+), 811 deletions(-)
 create mode 100644 samples/utils/CommandLineUtils.cpp
 create mode 100644 samples/utils/CommandLineUtils.h

diff --git a/samples/greengrass/basic_discovery/CMakeLists.txt b/samples/greengrass/basic_discovery/CMakeLists.txt
index ef6c68646..891fe830a 100644
--- a/samples/greengrass/basic_discovery/CMakeLists.txt
+++ b/samples/greengrass/basic_discovery/CMakeLists.txt
@@ -4,6 +4,8 @@ project(basic-discovery CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/greengrass/basic_discovery/main.cpp b/samples/greengrass/basic_discovery/main.cpp
index 53892aa70..ef367db45 100644
--- a/samples/greengrass/basic_discovery/main.cpp
+++ b/samples/greengrass/basic_discovery/main.cpp
@@ -14,47 +14,11 @@
 #include <iostream>
 #include <mutex>
 
+#include "../../utils/CommandLineUtils.h"
+
 using namespace Aws::Crt;
 using namespace Aws::Discovery;
 
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "basic-discovery --region <optional: region> --cert <path to cert>"
-        " --key <path to key> --ca_file <optional: path to custom ca>"
-        " --thing_name <thing name> --topic <optional: topic> "
-        " --mode <optional: both|publish|subscribe> --message <optional: message to publish>"
-        " --proxy-host <optional: proxy host name> --proxy-port <optional: proxy port>\n\n");
-    fprintf(stdout, "region: the region for your green grass groups, default us-east-1\n");
-    fprintf(stdout, "cert: path to your client certificate in PEM format\n");
-    fprintf(stdout, "key: path to your key in PEM format\n");
-    fprintf(stdout, "ca_file: ca file to use in verifying TLS connections.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "thing_name: the name of your IOT thing\n");
-    fprintf(stdout, "topic: targeted topic. Default is test/topic\n");
-    fprintf(stdout, "mode: default both\n");
-    fprintf(stdout, "message: message to publish. default 'Hello World'\n");
-    fprintf(stdout, "proxy-host: proxy host to use for discovery call. Default is to not use a proxy.\n");
-    fprintf(stdout, "proxy-port: proxy port to use for discovery call.\n");
-}
-
-bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
-
 int main(int argc, char *argv[])
 {
     /************************ Setup the Lib ****************************/
@@ -75,50 +39,37 @@ int main(int argc, char *argv[])
     String message("Hello World");
 
     /*********************** Parse Arguments ***************************/
-    if (!(s_cmdOptionExists(argv, argv + argc, "--cert") && s_cmdOptionExists(argv, argv + argc, "--key") &&
-          s_cmdOptionExists(argv, argv + argc, "--thing_name")))
-    {
-        s_printHelp();
-        return 0;
-    }
-
-    certificatePath = s_getCmdOption(argv, argv + argc, "--cert");
-    keyPath = s_getCmdOption(argv, argv + argc, "--key");
-    thingName = s_getCmdOption(argv, argv + argc, "--thing_name");
-
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("basic-discovery");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.AddCommonProxyCommands();
+    cmdUtils.AddCommonTopicMessageCommands();
+    cmdUtils.RemoveCommand("endpoint");
+    cmdUtils.RegisterCommand(
+        "region", "<str>", "The region for your Greengrass groups (optional, default='us-east-1').");
+    cmdUtils.RegisterCommand("thing_name", "<str>", "The name of your IOT thing");
+    cmdUtils.RegisterCommand(
+        "mode", "<str>", "Mode options: 'both', 'publish', or 'subscribe' (optional, default='both').");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--region"))
-    {
-        region = s_getCmdOption(argv, argv + argc, "--region");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--topic"))
-    {
-        topic = s_getCmdOption(argv, argv + argc, "--topic");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--mode"))
-    {
-        mode = s_getCmdOption(argv, argv + argc, "--mode");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--message"))
-    {
-        message = s_getCmdOption(argv, argv + argc, "--message");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--proxy-host"))
-    {
-        proxyHost = s_getCmdOption(argv, argv + argc, "--proxy-host");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--proxy-port"))
+    certificatePath = cmdUtils.GetCommandRequired("cert");
+    keyPath = cmdUtils.GetCommandRequired("key");
+    thingName = cmdUtils.GetCommandRequired("thing_name");
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", caFile);
+    region = cmdUtils.GetCommandOrDefault("region", region);
+    topic = cmdUtils.GetCommandOrDefault("topic", topic);
+    mode = cmdUtils.GetCommandOrDefault("mode", mode);
+    message = cmdUtils.GetCommandOrDefault("message", message);
+    proxyHost = cmdUtils.GetCommandOrDefault("proxy_host", proxyHost);
+    if (cmdUtils.HasCommand("proxy_port"))
     {
-        String portString = s_getCmdOption(argv, argv + argc, "--proxy-port");
+        String portString = cmdUtils.GetCommand("proxy_port");
         proxyPort = static_cast<uint16_t>(atoi(portString.c_str()));
     }
 
diff --git a/samples/greengrass/ipc/CMakeLists.txt b/samples/greengrass/ipc/CMakeLists.txt
index 6af6170b5..646a7868f 100644
--- a/samples/greengrass/ipc/CMakeLists.txt
+++ b/samples/greengrass/ipc/CMakeLists.txt
@@ -4,6 +4,8 @@ project(greengrass-ipc CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/greengrass/ipc/main.cpp b/samples/greengrass/ipc/main.cpp
index 03840df8f..fa0356ea1 100644
--- a/samples/greengrass/ipc/main.cpp
+++ b/samples/greengrass/ipc/main.cpp
@@ -7,35 +7,14 @@
 
 #include <aws/greengrass/GreengrassCoreIpcClient.h>
 
+#include "../../utils/CommandLineUtils.h"
+
 using namespace Aws::Crt;
 using namespace Aws::Greengrass;
 
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(stdout, "greengrass-ipc --topic <optional: topic> --message <optional: message to publish>\n\n");
-    fprintf(stdout, "topic: targeted topic. Default is test/topic\n");
-    fprintf(stdout, "message: message to publish. default 'Hello World'\n");
-}
-
 /* Used to check that the publish has been received so that the demo can exit successfully. */
 static std::atomic_bool s_publishReceived(false);
 
-bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
-
 int main(int argc, char *argv[])
 {
     /************************ Setup the Lib ****************************/
@@ -48,21 +27,19 @@ int main(int argc, char *argv[])
     String message("Hello World");
 
     /*********************** Parse Arguments ***************************/
-    if (s_cmdOptionExists(argv, argv + argc, "--help"))
-    {
-        s_printHelp();
-        return 0;
-    }
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("greengrass-ipc");
+    cmdUtils.AddCommonTopicMessageCommands();
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
 
-    if (s_cmdOptionExists(argv, argv + argc, "--topic"))
+    if (cmdUtils.HasCommand("help"))
     {
-        topic = s_getCmdOption(argv, argv + argc, "--topic");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--message"))
-    {
-        message = s_getCmdOption(argv, argv + argc, "--message");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
+    topic = cmdUtils.GetCommandOrDefault("topic", topic);
+    message = cmdUtils.GetCommandOrDefault("message", message);
 
     /**
      * Create the default ClientBootstrap, which will create the default
diff --git a/samples/identity/fleet_provisioning/CMakeLists.txt b/samples/identity/fleet_provisioning/CMakeLists.txt
index c876fd512..52b9fb458 100644
--- a/samples/identity/fleet_provisioning/CMakeLists.txt
+++ b/samples/identity/fleet_provisioning/CMakeLists.txt
@@ -4,6 +4,8 @@ project(fleet-provisioning CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/identity/fleet_provisioning/main.cpp b/samples/identity/fleet_provisioning/main.cpp
index 9f0a2acc6..b1478b59c 100644
--- a/samples/identity/fleet_provisioning/main.cpp
+++ b/samples/identity/fleet_provisioning/main.cpp
@@ -32,47 +32,13 @@
 #include <string>
 #include <thread>
 
+#include "../../utils/CommandLineUtils.h"
+
 using namespace Aws::Crt;
 using namespace Aws::Iotidentity;
 using namespace std::this_thread; // sleep_for, sleep_until
 using namespace std::chrono;      // nanoseconds, system_clock, seconds
 
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "fleet-provisioning --endpoint <endpoint> --ca_file <optional: path to custom ca> --cert <path to cert>"
-        " --key <path to key> --templateName <template name> --templateParameters <template parameters> --csr "
-        "<optional: path to csr> \n\n");
-    fprintf(stdout, "endpoint: the endpoint of the mqtt server not including a port\n");
-    fprintf(stdout, "cert: path to your client certificate in PEM format\n");
-    fprintf(stdout, "csr: path to CSR in PEM format\n");
-    fprintf(stdout, "key: path to your key in PEM format\n");
-    fprintf(
-        stdout,
-        "ca_file: Optional, if the mqtt server uses a certificate that's not already"
-        " in your trust store, set this.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "template_name: the name of your provisioning template\n");
-    fprintf(stdout, "template_parameters: template parameters json\n");
-}
-
-static bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-static char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
-
 static void sleep(int sleeptime)
 {
     std::cout << "Sleeping for " << sleeptime << " seconds..." << std::endl;
@@ -110,29 +76,29 @@ int main(int argc, char *argv[])
     apiHandle.InitializeLogging(Aws::Crt::LogLevel::Trace, stderr);
 
     /*********************** Parse Arguments ***************************/
-    if (!(s_cmdOptionExists(argv, argv + argc, "--endpoint") && s_cmdOptionExists(argv, argv + argc, "--cert") &&
-          s_cmdOptionExists(argv, argv + argc, "--key") && s_cmdOptionExists(argv, argv + argc, "--template_name") &&
-          s_cmdOptionExists(argv, argv + argc, "--template_parameters")))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("fleet-provisioning");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.RegisterCommand("template_name", "<str>", "The name of your provisioning template");
+    cmdUtils.RegisterCommand("template_parameters", "<json>", "Template parameters json");
+    cmdUtils.RegisterCommand("csr", "<path>", "Path to CSR in PEM format (optional)");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        s_printHelp();
-        return 0;
-    }
-
-    endpoint = s_getCmdOption(argv, argv + argc, "--endpoint");
-    certificatePath = s_getCmdOption(argv, argv + argc, "--cert");
-    keyPath = s_getCmdOption(argv, argv + argc, "--key");
-    templateName = s_getCmdOption(argv, argv + argc, "--template_name");
-    templateParameters = s_getCmdOption(argv, argv + argc, "--template_parameters");
-
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
-    {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
-
-    // if CSRFile provided
-    if (s_cmdOptionExists(argv, argv + argc, "--csr"))
+    endpoint = cmdUtils.GetCommandRequired("endpoint");
+    certificatePath = cmdUtils.GetCommandRequired("cert");
+    keyPath = cmdUtils.GetCommandRequired("key");
+    templateName = cmdUtils.GetCommandRequired("template_name");
+    templateParameters = cmdUtils.GetCommandRequired("template_parameters");
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", caFile);
+    if (cmdUtils.HasCommand("csr"))
     {
-        csrFile = getFileData(s_getCmdOption(argv, argv + argc, "--csr")).c_str();
+        csrFile = getFileData(cmdUtils.GetCommand("csr").c_str()).c_str();
     }
 
     /********************** Now Setup an Mqtt Client ******************/
diff --git a/samples/jobs/describe_job_execution/CMakeLists.txt b/samples/jobs/describe_job_execution/CMakeLists.txt
index 719f717ab..789e1b0a9 100644
--- a/samples/jobs/describe_job_execution/CMakeLists.txt
+++ b/samples/jobs/describe_job_execution/CMakeLists.txt
@@ -4,6 +4,8 @@ project(describe-job-execution CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/jobs/describe_job_execution/main.cpp b/samples/jobs/describe_job_execution/main.cpp
index c42d77776..e2bc0bd0d 100644
--- a/samples/jobs/describe_job_execution/main.cpp
+++ b/samples/jobs/describe_job_execution/main.cpp
@@ -19,44 +19,11 @@
 #include <iostream>
 #include <mutex>
 
+#include "../../utils/CommandLineUtils.h"
+
 using namespace Aws::Crt;
 using namespace Aws::Iotjobs;
 
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "describe-job-execution --endpoint <endpoint> --cert <path to cert>"
-        " --key <path to key> --ca_file <optional: path to custom ca>"
-        " --thing_name <thing name> --job_id <job id>\n\n");
-    fprintf(stdout, "endpoint: the endpoint of the mqtt server not including a port\n");
-    fprintf(stdout, "cert: path to your client certificate in PEM format\n");
-    fprintf(stdout, "key: path to your key in PEM format\n");
-    fprintf(
-        stdout,
-        "ca_file: Optional, if the mqtt server uses a certificate that's not already"
-        " in your trust store, set this.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "thing_name: the name of your IOT thing\n");
-    fprintf(stdout, "job_id: the job id you want to describe.\n");
-}
-
-bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
-
 int main(int argc, char *argv[])
 {
     /************************ Setup the Lib ****************************/
@@ -74,24 +41,25 @@ int main(int argc, char *argv[])
     String jobId;
 
     /*********************** Parse Arguments ***************************/
-    if (!(s_cmdOptionExists(argv, argv + argc, "--endpoint") && s_cmdOptionExists(argv, argv + argc, "--cert") &&
-          s_cmdOptionExists(argv, argv + argc, "--key") && s_cmdOptionExists(argv, argv + argc, "--thing_name") &&
-          s_cmdOptionExists(argv, argv + argc, "--job_id")))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("describe-job-execution");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.RegisterCommand("thing_name", "<str>", "The name of your IOT thing.");
+    cmdUtils.RegisterCommand("job_id", "<str>", "The job id you want to describe.");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        s_printHelp();
-        return 0;
-    }
-
-    endpoint = s_getCmdOption(argv, argv + argc, "--endpoint");
-    certificatePath = s_getCmdOption(argv, argv + argc, "--cert");
-    keyPath = s_getCmdOption(argv, argv + argc, "--key");
-    thingName = s_getCmdOption(argv, argv + argc, "--thing_name");
-    jobId = s_getCmdOption(argv, argv + argc, "--job_id");
-
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
-    {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
+    endpoint = cmdUtils.GetCommandRequired("endpoint");
+    certificatePath = cmdUtils.GetCommandRequired("cert");
+    keyPath = cmdUtils.GetCommandRequired("key");
+    thingName = cmdUtils.GetCommandRequired("thing_name");
+    jobId = cmdUtils.GetCommandRequired("job_id");
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", caFile);
 
     /********************** Now Setup an Mqtt Client ******************/
     if (apiHandle.GetOrCreateStaticDefaultClientBootstrap()->LastError() != AWS_ERROR_SUCCESS)
diff --git a/samples/mqtt/basic_pub_sub/CMakeLists.txt b/samples/mqtt/basic_pub_sub/CMakeLists.txt
index bedaf81d1..c50d4227f 100644
--- a/samples/mqtt/basic_pub_sub/CMakeLists.txt
+++ b/samples/mqtt/basic_pub_sub/CMakeLists.txt
@@ -4,6 +4,8 @@ project(basic-pub-sub CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/mqtt/basic_pub_sub/main.cpp b/samples/mqtt/basic_pub_sub/main.cpp
index 0d46c270f..3bc743826 100644
--- a/samples/mqtt/basic_pub_sub/main.cpp
+++ b/samples/mqtt/basic_pub_sub/main.cpp
@@ -16,70 +16,9 @@
 #include <iostream>
 #include <mutex>
 
-using namespace Aws::Crt;
+#include "../../utils/CommandLineUtils.h"
 
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "basic-pub-sub --endpoint <endpoint> --cert <path to cert>"
-        " --key <path to key> --topic <topic> --message <message> --count <count>"
-        " --client_id <client id> --ca_file <optional: path to custom ca>"
-        " --use_websocket --signing_region <region> --proxy_host <host> --proxy_port <port>"
-        " --x509 --x509_role_alias <role_alias> --x509_endpoint <endpoint> --x509_thing <thing_name>"
-        " --x509_cert <path to cert> --x509_key <path to key> --x509_rootca <path to root ca>\n\n");
-    fprintf(stdout, "endpoint: the endpoint of the mqtt server not including a port\n");
-    fprintf(
-        stdout,
-        "cert: path to your client certificate in PEM format. If this is not set you must specify use_websocket\n");
-    fprintf(stdout, "key: path to your key in PEM format. If this is not set you must specify use_websocket\n");
-    fprintf(stdout, "topic: topic to publish, subscribe to. (optional)\n");
-    fprintf(stdout, "message: override payload of published messages. (optional, defaults to \"Hello world!\"))\n");
-    fprintf(stdout, "count: number of messages to publish. (optional, defaults to 10)\n");
-    fprintf(stdout, "client_id: client id to use (optional)\n");
-    fprintf(
-        stdout,
-        "ca_file: Optional, if the mqtt server uses a certificate that's not already"
-        " in your trust store, set this.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "use_websocket: if specified, uses a websocket over https (optional)\n");
-    fprintf(
-        stdout,
-        "signing_region: used for websocket signer it should only be specific if websockets are used. (required for "
-        "websockets)\n");
-    fprintf(stdout, "proxy_host: host name of the http proxy to use (optional).\n");
-    fprintf(stdout, "proxy_port: port of the http proxy to use (optional).\n");
-
-    fprintf(stdout, "  x509: Use the x509 credentials provider while using websockets (optional)\n");
-    fprintf(stdout, "  x509_role_alias: Role alias to use with the x509 credentials provider (required for x509)\n");
-    fprintf(stdout, "  x509_endpoint: Endpoint to fetch x509 credentials from (required for x509)\n");
-    fprintf(stdout, "  x509_thing: Thing name to fetch x509 credentials on behalf of (required for x509)\n");
-    fprintf(
-        stdout,
-        "  x509_cert: Path to the IoT thing certificate used in fetching x509 credentials (required for x509)\n");
-    fprintf(
-        stdout,
-        "  x509_key: Path to the IoT thing private key used in fetching x509 credentials (required for x509)\n");
-    fprintf(
-        stdout,
-        "  x509_rootca: Path to the root certificate used in fetching x509 credentials (required for x509)\n\n");
-}
-
-bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
+using namespace Aws::Crt;
 
 int main(int argc, char *argv[])
 {
@@ -114,74 +53,64 @@ int main(int argc, char *argv[])
     String messagePayload("Hello world!");
 
     /*********************** Parse Arguments ***************************/
-    if (!s_cmdOptionExists(argv, argv + argc, "--endpoint"))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("basic_pub_sub");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.AddCommonProxyCommands();
+    cmdUtils.AddCommonTopicMessageCommands();
+    cmdUtils.AddCommonX509Commands();
+    cmdUtils.AddCommonWebsocketCommands();
+    cmdUtils.UpdateCommandHelp(
+        "key", "Path to your key in PEM format. If this is not set you must specify use_websocket");
+    cmdUtils.UpdateCommandHelp(
+        "cert", "Path to your client certificate in PEM format. If this is not set you must specify use_websocket");
+    cmdUtils.RegisterCommand(
+        "client_id",
+        "<str>"
+        "Client id to use (optional, default='test-*')");
+    cmdUtils.RegisterCommand("count", "<int>", "The number of messages to send (optional, default='10')");
+    cmdUtils.RegisterCommand("help", "", "Prints this message");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        s_printHelp();
-        return 1;
-    }
-
-    endpoint = s_getCmdOption(argv, argv + argc, "--endpoint");
-
-    if (s_cmdOptionExists(argv, argv + argc, "--key"))
-    {
-        keyPath = s_getCmdOption(argv, argv + argc, "--key");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--cert"))
-    {
-        certificatePath = s_getCmdOption(argv, argv + argc, "--cert");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
-
+    endpoint = cmdUtils.GetCommandRequired("endpoint");
+    keyPath = cmdUtils.GetCommandOrDefault("key", keyPath);
+    certificatePath = cmdUtils.GetCommandOrDefault("cert", certificatePath);
     if (keyPath.empty() != certificatePath.empty())
     {
-        fprintf(stdout, "Using mtls (cert and key) requires both the certificate and the private key\n");
-        s_printHelp();
+        cmdUtils.PrintHelp();
+        fprintf(stdout, "Using mtls (cert and key) requires both the certificate and private key\n");
         return 1;
     }
-    if (s_getCmdOption(argv, argv + argc, "--topic"))
-    {
-        topic = s_getCmdOption(argv, argv + argc, "--topic");
-    }
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
+    topic = cmdUtils.GetCommandOrDefault("topic", topic);
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", caFile);
+    clientId = cmdUtils.GetCommandOrDefault("client_id", clientId);
+    if (cmdUtils.HasCommand("use_websocket"))
     {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
-    }
-    if (s_cmdOptionExists(argv, argv + argc, "--client_id"))
-    {
-        clientId = s_getCmdOption(argv, argv + argc, "--client_id");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--use_websocket"))
-    {
-        if (!s_cmdOptionExists(argv, argv + argc, "--signing_region"))
-        {
-            fprintf(stdout, "Websockets require a signing region to be specified.\n");
-            s_printHelp();
-            return 1;
-        }
         useWebSocket = true;
-        signingRegion = s_getCmdOption(argv, argv + argc, "--signing_region");
+        signingRegion =
+            cmdUtils.GetCommandRequired("signing_region", "Websockets require a signing region to be specified.");
     }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--proxy_host"))
+    proxyHost = cmdUtils.GetCommandOrDefault("proxy_host", proxyHost);
+    if (cmdUtils.HasCommand("prox_port"))
     {
-        proxyHost = s_getCmdOption(argv, argv + argc, "--proxy_host");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--proxy_port"))
-    {
-        int port = atoi(s_getCmdOption(argv, argv + argc, "--proxy_port"));
-        if (port > 0 && port <= UINT16_MAX)
+        int port = atoi(cmdUtils.GetCommand("proxy_port").c_str());
+        if (port > 0 && port < UINT16_MAX)
         {
             proxyPort = static_cast<uint16_t>(port);
         }
     }
-
     bool usingMtls = !certificatePath.empty() && !keyPath.empty();
 
     /* one or the other, but not both nor neither */
     if (useWebSocket == usingMtls)
     {
+        cmdUtils.PrintHelp();
         if (useWebSocket && usingMtls)
         {
             fprintf(stdout, "You must use either websockets or mtls for authentication, but not both.\n");
@@ -190,77 +119,35 @@ int main(int argc, char *argv[])
         {
             fprintf(stdout, "You must use either websockets or mtls for authentication.\n");
         }
-
-        s_printHelp();
         return 1;
     }
 
     // x509 credentials provider configuration
-    if (s_cmdOptionExists(argv, argv + argc, "--x509"))
+    if (cmdUtils.HasCommand("x509"))
     {
         if (!useWebSocket)
         {
+            cmdUtils.PrintHelp();
             fprintf(stdout, "X509 credentials sourcing requires websockets to be enabled and configured.\n");
-            s_printHelp();
             return 1;
         }
-
-        if (!s_cmdOptionExists(argv, argv + argc, "--x509_role_alias"))
-        {
-            fprintf(stdout, "X509 credentials sourcing requires an x509 role alias to be specified.\n");
-            s_printHelp();
-            return 1;
-        }
-        x509RoleAlias = s_getCmdOption(argv, argv + argc, "--x509_role_alias");
-
-        if (!s_cmdOptionExists(argv, argv + argc, "--x509_endpoint"))
-        {
-            fprintf(stdout, "X509 credentials sourcing requires an x509 endpoint to be specified.\n");
-            s_printHelp();
-            return 1;
-        }
-        x509Endpoint = s_getCmdOption(argv, argv + argc, "--x509_endpoint");
-
-        if (!s_cmdOptionExists(argv, argv + argc, "--x509_thing"))
-        {
-            fprintf(stdout, "X509 credentials sourcing requires an x509 thing name to be specified.\n");
-            s_printHelp();
-            return 1;
-        }
-        x509ThingName = s_getCmdOption(argv, argv + argc, "--x509_thing");
-
-        if (!s_cmdOptionExists(argv, argv + argc, "--x509_cert"))
-        {
-            fprintf(stdout, "X509 credentials sourcing requires an Iot thing certificate to be specified.\n");
-            s_printHelp();
-            return 1;
-        }
-        x509CertificatePath = s_getCmdOption(argv, argv + argc, "--x509_cert");
-
-        if (!s_cmdOptionExists(argv, argv + argc, "--x509_key"))
-        {
-            fprintf(stdout, "X509 credentials sourcing requires an Iot thing private key to be specified.\n");
-            s_printHelp();
-            return 1;
-        }
-        x509KeyPath = s_getCmdOption(argv, argv + argc, "--x509_key");
-
-        if (s_cmdOptionExists(argv, argv + argc, "--x509_rootca"))
-        {
-            x509RootCAFile = s_getCmdOption(argv, argv + argc, "--x509_rootca");
-        }
-
-        useX509 = true;
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--message"))
-    {
-        messagePayload = s_getCmdOption(argv, argv + argc, "--message");
+        x509RoleAlias = cmdUtils.GetCommandRequired(
+            "x509_role_alias", "X509 credentials sourcing requires an x509 role alias to be specified.");
+        x509Endpoint = cmdUtils.GetCommandRequired(
+            "x509_endpoint", "X509 credentials sourcing requires an x509 endpoint to be specified.");
+        x509ThingName = cmdUtils.GetCommandRequired(
+            "x509_thing", "X509 credentials sourcing requires an x509 thing name to be specified.");
+        x509CertificatePath = cmdUtils.GetCommandRequired(
+            "x509_cert", "X509 credentials sourcing requires an IoT certificate to be specified.");
+        x509KeyPath = cmdUtils.GetCommandRequired(
+            "x509_key", "X509 credentials sourcing requires an IoT thing private key to be specified.");
+        x509RootCAFile = cmdUtils.GetCommandOrDefault("x509_ca_file", x509RootCAFile);
     }
 
-    if (s_cmdOptionExists(argv, argv + argc, "--count"))
+    messagePayload = cmdUtils.GetCommandOrDefault("message", messagePayload);
+    if (cmdUtils.HasCommand("count"))
     {
-        int count = atoi(s_getCmdOption(argv, argv + argc, "--count"));
+        int count = atoi(cmdUtils.GetCommand("count").c_str());
         if (count > 0)
         {
             messageCount = count;
@@ -363,7 +250,7 @@ int main(int argc, char *argv[])
     }
     else
     {
-        s_printHelp();
+        cmdUtils.PrintHelp();
     }
 
     if (!proxyHost.empty())
diff --git a/samples/mqtt/pkcs11_pub_sub/CMakeLists.txt b/samples/mqtt/pkcs11_pub_sub/CMakeLists.txt
index 1a9f02e12..8d5b02beb 100644
--- a/samples/mqtt/pkcs11_pub_sub/CMakeLists.txt
+++ b/samples/mqtt/pkcs11_pub_sub/CMakeLists.txt
@@ -4,6 +4,8 @@ project(pkcs11-pub-sub CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/mqtt/pkcs11_pub_sub/main.cpp b/samples/mqtt/pkcs11_pub_sub/main.cpp
index 527117237..3c6e20a8d 100644
--- a/samples/mqtt/pkcs11_pub_sub/main.cpp
+++ b/samples/mqtt/pkcs11_pub_sub/main.cpp
@@ -7,96 +7,9 @@
 #include <aws/crt/io/Pkcs11.h>
 #include <aws/iot/MqttClient.h>
 
-using namespace Aws::Crt;
-
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "basic-pub-sub"
-        " --endpoint <hostname>"
-        " --cert <path>"
-        " --pkcs11_lib <path>"
-        " --pin <str>"
-        " [--token_label <str>]"
-        " [--slot_id <int>]"
-        " [--key_label <str>]"
-        " [--topic <mqtt topic>]"
-        " [--message <str>]"
-        " [--count <int>]"
-        " [--client_id <str>]"
-        " [--ca_file <path>]"
-        "\n\n");
-    fprintf(stdout, "endpoint       Endpoint of the mqtt server not including a port.\n");
-    fprintf(stdout, "cert           Path to your client certificate in PEM format.\n");
-    fprintf(stdout, "pkcs11_lib     Path to PKCS#11 library.\n");
-    fprintf(stdout, "pin            User PIN for logging into PKCS#11 token.\n");
-    fprintf(stdout, "token_label    Label of the PKCS#11 token to use (optional).\n");
-    fprintf(stdout, "slot_id        Slot ID containing PKCS#11 token to use (optional).\n");
-    fprintf(stdout, "key_label      Label of private key on the PKCS#11 token (optional).\n");
-    fprintf(stdout, "topic          MQTT topic for subscribe and publish (optional, default='/test/topic').\n");
-    fprintf(stdout, "message        MQTT message to publish (optional, default='Hello World!').\n");
-    fprintf(stdout, "count          Number of messages to publish. (optional, default=10).\n");
-    fprintf(stdout, "client_id      Client id to use (optional, default='test-*').\n");
-    fprintf(stdout, "ca_file:       Path to AmazonRootCA1.pem (optional, system trust store used by default).\n");
-    fprintf(stdout, "\n");
-}
-
-class ArgParser
-{
-  public:
-    ArgParser(int argc, char *argv[])
-    {
-        m_argv = argv;
-        m_argvEnd = argv + argc;
-
-        if (Exists("--help"))
-        {
-            s_printHelp();
-            exit(0);
-        }
-    }
-
-    bool Exists(const String &name) const { return std::find(m_argv, m_argvEnd, name) != m_argvEnd; }
-
-    String GetRequired(const String &name) const
-    {
-        const char *val = FindValue(name);
-        if (val == nullptr)
-        {
-            s_printHelp();
-            fprintf(stderr, "Missing required argument: %s\n", name.c_str());
-            exit(-1);
-        }
-        return val;
-    }
-
-    String GetOptional(const String &name, const String &defaultVal)
-    {
-        const char *val = FindValue(name);
-        if (val == nullptr)
-        {
-            return defaultVal;
-        }
-        return val;
-    }
-
-  private:
-    const char *FindValue(const String &name) const
-    {
-        char **itr = std::find(m_argv, m_argvEnd, name);
-        if (itr == m_argvEnd || ++itr == m_argvEnd)
-        {
-            return nullptr;
-        }
-        return *itr;
-    }
+#include "../../utils/CommandLineUtils.h"
 
-  private:
-    char **m_argv;
-    char **m_argvEnd;
-};
+using namespace Aws::Crt;
 
 int main(int argc, char *argv[])
 {
@@ -110,20 +23,39 @@ int main(int argc, char *argv[])
     // apiHandle.InitializeLogging(LogLevel::Error, stderr);
 
     /*********************** Parse Arguments ***************************/
-    ArgParser args(argc, argv);
-
-    String endpoint = args.GetRequired("--endpoint");
-    String certificatePath = args.GetRequired("--cert");
-    String pkcs11LibPath = args.GetRequired("--pkcs11_lib");
-    String pkcs11UserPin = args.GetRequired("--pin");
-    String pkcs11TokenLabel = args.GetOptional("--token_label", "");
-    String pkcs11SlotIdStr = args.GetOptional("--slot_id", "");
-    String pkcs11KeyLabel = args.GetOptional("--key_label", "");
-    String topic = args.GetOptional("--topic", "test/topic");
-    String messagePayload = args.GetOptional("--message", "Hello world!");
-    int messageCount = std::stoi(args.GetOptional("--count", "10").c_str());
-    String caFile = args.GetOptional("--ca_file", "");
-    String clientId = args.GetOptional("--client_id", String("test-") + Aws::Crt::UUID().ToString());
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("pkcs11_pub_sub");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.AddCommonTopicMessageCommands();
+    cmdUtils.RemoveCommand("key");
+    cmdUtils.RegisterCommand("pkcs11_lib", "<path>", "Path to PKCS#11 library.");
+    cmdUtils.RegisterCommand("pin", "<str>", "User PIN for logging into PKCS#11 token.");
+    cmdUtils.RegisterCommand("token_label", "<str>", "Label of the PKCS#11 token to use (optional).");
+    cmdUtils.RegisterCommand("slot_id", "<int>", "Slot ID containing PKCS#11 token to use (optional).");
+    cmdUtils.RegisterCommand("key_label", "<str>", "Label of private key on the PKCS#11 token (optional).");
+    cmdUtils.RegisterCommand("count", "<int>", "Number of messages to publish. (optional, default=10).");
+    cmdUtils.RegisterCommand("client_id", "<str>", "Client id to use (optional, default='test-*').");
+    cmdUtils.RegisterCommand("help", "", "Prints this message");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
+    {
+        cmdUtils.PrintHelp();
+        exit(-1);
+    }
+    String endpoint = cmdUtils.GetCommandRequired("endpoint");
+    String certificatePath = cmdUtils.GetCommandRequired("cert");
+    String pkcs11LibPath = cmdUtils.GetCommandRequired("pkcs11_lib");
+    String pkcs11UserPin = cmdUtils.GetCommandRequired("pin");
+    String pkcs11TokenLabel = cmdUtils.GetCommandOrDefault("token_label", "");
+    String pkcs11SlotIdStr = cmdUtils.GetCommandOrDefault("slot_id", "");
+    String pkcs11KeyLabel = cmdUtils.GetCommandOrDefault("key_label", "");
+    String topic = cmdUtils.GetCommandOrDefault("topic", "test/topic");
+    String messagePayload = cmdUtils.GetCommandOrDefault("message", "Hello world!");
+    int messageCount = std::stoi(cmdUtils.GetCommandOrDefault("count", "10").c_str());
+    String caFile = cmdUtils.GetCommandOrDefault("ca_file", "");
+    String clientId = cmdUtils.GetCommandOrDefault("client_id", String("test-") + Aws::Crt::UUID().ToString());
 
     /********************** Now Setup an Mqtt Client ******************/
     if (apiHandle.GetOrCreateStaticDefaultClientBootstrap()->LastError() != AWS_ERROR_SUCCESS)
diff --git a/samples/mqtt/raw_pub_sub/CMakeLists.txt b/samples/mqtt/raw_pub_sub/CMakeLists.txt
index e13dd0aec..ecc316db4 100644
--- a/samples/mqtt/raw_pub_sub/CMakeLists.txt
+++ b/samples/mqtt/raw_pub_sub/CMakeLists.txt
@@ -4,6 +4,8 @@ project(raw-pub-sub CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/mqtt/raw_pub_sub/main.cpp b/samples/mqtt/raw_pub_sub/main.cpp
index 7cb395b14..b55401f41 100644
--- a/samples/mqtt/raw_pub_sub/main.cpp
+++ b/samples/mqtt/raw_pub_sub/main.cpp
@@ -15,53 +15,9 @@
 #include <iostream>
 #include <mutex>
 
-using namespace Aws::Crt;
-
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "raw-pub-sub --endpoint <endpoint> --cert <path to cert>"
-        " --key <path to key> --topic <topic> --ca_file <optional: path to custom ca>"
-        " --use_websocket --user_name <username> --password <password> --protocol_name <protocol> "
-        " --auth_params=<comma delimited list> --proxy_host <host> --proxy_port <port>\n\n");
-    fprintf(stdout, "endpoint: the endpoint of the mqtt server not including a port\n");
-    fprintf(stdout, "cert: path to your client certificate in PEM format. Don't use with use_websocket\n");
-    fprintf(stdout, "key: path to your key in PEM format. Dont use with use_websocket\n");
-    fprintf(stdout, "topic: topic to publish, subscribe to. (optional)\n");
-    fprintf(stdout, "client_id: client id to use (optional)\n");
-    fprintf(
-        stdout,
-        "ca_file: Optional, if the mqtt server uses a certificate that's not already"
-        " in your trust store, set this.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "use_websocket: if specified, uses a websocket over https (optional)\n");
-    fprintf(stdout, "proxy_host: host name of the http proxy to use (optional).\n");
-    fprintf(stdout, "proxy_port: port of the http proxy to use (optional).\n");
-    fprintf(stdout, "user_name: User name to send with mqtt connect.\n");
-    fprintf(stdout, "password: Password to send with mqtt connect.\n");
-    fprintf(stdout, "protocol_name: (optional) defaults to x-amzn-mqtt-ca.\n");
-    fprintf(
-        stdout,
-        "auth_params: (optional) Comma delimited list of auth parameters. For websockets these will be set as headers. "
-        "For raw mqtt these will be appended to user_name.\n\n");
-}
+#include "../../utils/CommandLineUtils.h"
 
-bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
+using namespace Aws::Crt;
 
 int main(int argc, char *argv[])
 {
@@ -91,73 +47,58 @@ int main(int argc, char *argv[])
     bool useWebSocket = false;
 
     /*********************** Parse Arguments ***************************/
-    if (!s_cmdOptionExists(argv, argv + argc, "--endpoint"))
-    {
-        s_printHelp();
-        return 0;
-    }
-
-    endpoint = s_getCmdOption(argv, argv + argc, "--endpoint");
-
-    if (s_cmdOptionExists(argv, argv + argc, "--key"))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("raw_pub_sub");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.AddCommonProxyCommands();
+    cmdUtils.AddCommonTopicMessageCommands();
+    cmdUtils.AddCommonWebsocketCommands();
+    cmdUtils.RemoveCommand("message");
+    cmdUtils.RemoveCommand("region");
+    cmdUtils.RegisterCommand("client_id", "<str>", "Client id to use (optional, default='test-*').");
+    cmdUtils.RegisterCommand("user_name", "<str>", "User name to send with mqtt connect.");
+    cmdUtils.RegisterCommand("password", "<str>", "Password to send with mqtt connect.");
+    cmdUtils.RegisterCommand(
+        "protocol_name", "<str>", "The X.509 client certificate auth (optional, default='x-amzn-mqtt-ca').");
+    cmdUtils.RegisterCommand(
+        "auth_params",
+        "<comma delimited list>",
+        "Comma delimited list of auth parameters. For websockets these will be set as headers (optional).");
+    cmdUtils.RegisterCommand(Utils::CommandLineOption("help", "", "Prints this message"));
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        keyPath = s_getCmdOption(argv, argv + argc, "--key");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--cert"))
-    {
-        certificatePath = s_getCmdOption(argv, argv + argc, "--cert");
-    }
-    if (s_getCmdOption(argv, argv + argc, "--topic"))
-    {
-        topic = s_getCmdOption(argv, argv + argc, "--topic");
-    }
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
-    {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
-    }
-    if (s_cmdOptionExists(argv, argv + argc, "--client_id"))
-    {
-        clientId = s_getCmdOption(argv, argv + argc, "--client_id");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
-    if (s_cmdOptionExists(argv, argv + argc, "--use_websocket"))
+    endpoint = cmdUtils.GetCommandRequired("endpoint");
+    keyPath = cmdUtils.GetCommandOrDefault("key", keyPath);
+    certificatePath = cmdUtils.GetCommandOrDefault("cert", certificatePath);
+    topic = cmdUtils.GetCommandOrDefault("topic", topic);
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", caFile);
+    clientId = cmdUtils.GetCommandOrDefault("client_id", clientId);
+    if (cmdUtils.HasCommand("use_websocket"))
     {
         protocolName = "http/1.1";
         useWebSocket = true;
     }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--proxy_host"))
-    {
-        proxyHost = s_getCmdOption(argv, argv + argc, "--proxy_host");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--proxy_port"))
+    proxyHost = cmdUtils.GetCommandOrDefault("proxy_host", proxyHost);
+    if (cmdUtils.HasCommand("proxy_port"))
     {
-        int port = atoi(s_getCmdOption(argv, argv + argc, "--proxy_port"));
+        int port = atoi(cmdUtils.GetCommand("proxy_port").c_str());
         if (port > 0 && port <= UINT16_MAX)
         {
             proxyPort = static_cast<uint16_t>(port);
         }
     }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--user_name"))
-    {
-        userName = s_getCmdOption(argv, argv + argc, "--user_name");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--password"))
-    {
-        password = s_getCmdOption(argv, argv + argc, "--password");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--protocol_name"))
-    {
-        protocolName = s_getCmdOption(argv, argv + argc, "--protocol_name");
-    }
-
-    if (s_cmdOptionExists(argv, argv + argc, "--auth_params"))
+    userName = cmdUtils.GetCommandOrDefault("user_name", userName);
+    password = cmdUtils.GetCommandOrDefault("password", password);
+    protocolName = cmdUtils.GetCommandOrDefault("protocol_name", protocolName);
+    if (cmdUtils.HasCommand("auth_params"))
     {
-        String params = s_getCmdOption(argv, argv + argc, "--auth_params");
+        String params = cmdUtils.GetCommand("auth_params");
         ByteCursor commaDelimitedParams = ByteCursorFromCString(params.c_str());
         ByteCursor split;
         AWS_ZERO_STRUCT(split);
@@ -226,13 +167,13 @@ int main(int argc, char *argv[])
                     AWS_ZERO_STRUCT(nameOrValue);
                     if (!aws_byte_cursor_next_split(&paramPair, '=', &nameOrValue))
                     {
-                        s_printHelp();
+                        cmdUtils.PrintHelp();
                         exit(-1);
                     }
                     header.name = nameOrValue;
                     if (!aws_byte_cursor_next_split(&paramPair, '=', &nameOrValue))
                     {
-                        s_printHelp();
+                        cmdUtils.PrintHelp();
                         exit(-1);
                     }
                     header.value = nameOrValue;
diff --git a/samples/secure_tunneling/secure_tunnel/CMakeLists.txt b/samples/secure_tunneling/secure_tunnel/CMakeLists.txt
index 0a16bc5d9..489c0a4b8 100644
--- a/samples/secure_tunneling/secure_tunnel/CMakeLists.txt
+++ b/samples/secure_tunneling/secure_tunnel/CMakeLists.txt
@@ -4,6 +4,8 @@ project(secure-tunnel CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/secure_tunneling/secure_tunnel/main.cpp b/samples/secure_tunneling/secure_tunnel/main.cpp
index 7e58c3999..0bfae5bcf 100644
--- a/samples/secure_tunneling/secure_tunnel/main.cpp
+++ b/samples/secure_tunneling/secure_tunnel/main.cpp
@@ -10,115 +10,80 @@
 
 #include <fstream>
 
-using namespace std;
+#include "../../utils/CommandLineUtils.h"
+
 using namespace Aws::Crt;
 using namespace Aws::Iotsecuretunneling;
 using namespace Aws::Crt::Io;
-
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "secure-tunnel\n"
-        "--region                <aws region of secure tunnel>\n"
-        "--ca_file               <optional: path to custom ca>\n"
-        "--access_token_file     <path to access token> or "
-        "--access_token          <access token>\n"
-        "--localProxyModeSource  <optional: sets to Source Mode>\n"
-        "--proxy_host            <host name of the proxy server>\n"
-        "--proxy_port            <port of the proxy server>\n"
-        "--proxy_user_name       <optional: user name>\n"
-        "--proxy_password        <optional: password>\n"
-        "--message               <optional: message to send>\n\n");
-    fprintf(stdout, "region: the region of your secure tunnel\n");
-    fprintf(
-        stdout,
-        "ca_file: Optional, if the mqtt server uses a certificate that's not already"
-        " in your trust store, set this.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "access_token_file: path to the tunneling access token file\n");
-    fprintf(stdout, "access_token: tunneling access token\n");
-    fprintf(stdout, "localProxyModeSource: Use to set local proxy mode to source. Default is destination\n");
-    fprintf(stdout, "proxy_host: Host name of the proxy server to connect through\n");
-    fprintf(stdout, "proxy_port: Port of the proxy server to connect through\n");
-    fprintf(stdout, "proxy_user_name: Optional, if proxy server requires a user name\n");
-    fprintf(stdout, "proxy_password: Optional, if proxy server requires a password\n");
-    fprintf(stdout, "message: message to send. Default: 'Hello World'\n");
-}
-
-bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
+using namespace std::chrono_literals;
 
 int main(int argc, char *argv[])
 {
     ApiHandle apiHandle;
 
-    string region;
-    string endpoint;
-    string caFile;
-    string accessToken;
-    string message = "Hello World";
+    String region;
+    String endpoint;
+    String caFile;
+    String accessToken;
+    String message = "Hello World";
     aws_secure_tunneling_local_proxy_mode localProxyMode;
 
-    string proxyHost;
+    String proxyHost;
     uint16_t proxyPort(8080);
-    string proxyUserName;
-    string proxyPassword;
-
-    /*
-     * For internal testing
-     */
-    bool isTest = s_cmdOptionExists(argv, argv + argc, "--test");
-    int expectedMessageCount = 5;
+    String proxyUserName;
+    String proxyPassword;
 
     std::shared_ptr<SecureTunnel> secureTunnel;
 
     /*********************** Parse Arguments ***************************/
-    if (!s_cmdOptionExists(argv, argv + argc, "--region"))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.AddCommonProxyCommands();
+    cmdUtils.RegisterProgramName("secure_tunnel");
+    cmdUtils.RegisterCommand("region", "<str>", "The region of your secure tunnel");
+    cmdUtils.RegisterCommand(
+        "ca_file", "<path>", "Path to AmazonRootCA1.pem (optional, system trust store used by default).");
+    cmdUtils.RegisterCommand(
+        "access_token_file", "<path>", "Path to the tunneling access token file (optional if --access_token used).");
+    cmdUtils.RegisterCommand("access_token", "<str>", "Tunneling access token (optional if --access_token_file used).");
+    cmdUtils.RegisterCommand(
+        "local_proxy_mode_source", "<str>", "Use to set local proxy mode to source (optional, default='destination').");
+    cmdUtils.RegisterCommand("message", "<str>", "Message to send (optional, default='Hello World!').");
+    cmdUtils.RegisterCommand("help", "", "Prints this message");
+    cmdUtils.RegisterCommand("test", "", "Used to trigger internal testing (optional, ignore unless testing).");
+    cmdUtils.RegisterCommand(
+        "proxy_user_name", "<str>", "User name passed if proxy server requires a user name (optional)");
+    cmdUtils.RegisterCommand(
+        "proxy_password", "<str>", "Password passed if proxy server requires a password (optional)");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        fprintf(stderr, "--region must be set to connect through a secure tunnel");
-        s_printHelp();
+        cmdUtils.PrintHelp();
         exit(-1);
     }
     /*
      * Generate secure tunneling endpoint using region
      */
-    region = s_getCmdOption(argv, argv + argc, "--region");
+    region = cmdUtils.GetCommandRequired("region");
     endpoint = "data.tunneling.iot." + region + ".amazonaws.com";
 
-    if (!(s_cmdOptionExists(argv, argv + argc, "--access_token_file") ||
-          s_cmdOptionExists(argv, argv + argc, "--access_token")))
+    if (!(cmdUtils.HasCommand("access_token_file") || cmdUtils.HasCommand("access_token")))
     {
+        cmdUtils.PrintHelp();
         fprintf(stderr, "--access_token_file or --access_token must be set to connect through a secure tunnel");
-        s_printHelp();
         exit(-1);
     }
 
-    /*
-     * Set accessToken either directly or from a file
-     */
-    if (s_cmdOptionExists(argv, argv + argc, "--access_token"))
+    if (cmdUtils.HasCommand("access_token"))
     {
-        accessToken = s_getCmdOption(argv, argv + argc, "--access_token");
+        accessToken = cmdUtils.GetCommand("access_token");
     }
-    else if (s_cmdOptionExists(argv, argv + argc, "--access_token_file"))
+    else
     {
-        accessToken = s_getCmdOption(argv, argv + argc, "--access_token_file");
+        accessToken = cmdUtils.GetCommand("access_token_file");
 
-        ifstream accessTokenFile(accessToken.c_str());
+        std::ifstream accessTokenFile(accessToken.c_str());
         if (accessTokenFile.is_open())
         {
             getline(accessTokenFile, accessToken);
@@ -130,48 +95,27 @@ int main(int argc, char *argv[])
             exit(-1);
         }
     }
-    if (s_cmdOptionExists(argv, argv + argc, "--proxy_host") || s_cmdOptionExists(argv, argv + argc, "--proxy_port"))
-    {
-        if (!s_cmdOptionExists(argv, argv + argc, "--proxy_host"))
-        {
-            fprintf(stderr, "--proxy_host must be set to connect through a proxy");
-            s_printHelp();
-            exit(-1);
-        }
-        proxyHost = s_getCmdOption(argv, argv + argc, "--proxy_host");
 
-        if (!s_cmdOptionExists(argv, argv + argc, "--proxy_port"))
-        {
-            fprintf(stderr, "--proxy_port must be set to connect through a proxy");
-            s_printHelp();
-            exit(-1);
-        }
-        int port = atoi(s_getCmdOption(argv, argv + argc, "--proxy_port"));
+    if (cmdUtils.HasCommand("proxy_host") || cmdUtils.HasCommand("proxy_port"))
+    {
+        proxyHost =
+            cmdUtils.GetCommandRequired("proxy_host", "--proxy_host must be set to connect through a proxy.").c_str();
+        int port = atoi(
+            cmdUtils.GetCommandRequired("proxy_port", "--proxy_port must be set to connect through a proxy.").c_str());
         if (port > 0 && port <= UINT16_MAX)
         {
             proxyPort = static_cast<uint16_t>(port);
         }
-
-        if (s_cmdOptionExists(argv, argv + argc, "--proxy_user_name"))
-        {
-            proxyUserName = s_getCmdOption(argv, argv + argc, "--proxy_user_name");
-        }
-
-        if (s_cmdOptionExists(argv, argv + argc, "--proxy_password"))
-        {
-            proxyPassword = s_getCmdOption(argv, argv + argc, "--proxy_password");
-        }
+        proxyUserName = cmdUtils.GetCommandOrDefault("proxy_user_name", "");
+        proxyPassword = cmdUtils.GetCommandOrDefault("proxy_password", "");
     }
 
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
-    {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
-    }
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", "");
 
     /*
      * localProxyMode is set to destination by default unless flag is set to source
      */
-    if (s_cmdOptionExists(argv, argv + argc, "--localProxyModeSource"))
+    if (cmdUtils.HasCommand("localProxyModeSource"))
     {
         localProxyMode = AWS_SECURE_TUNNELING_SOURCE_MODE;
     }
@@ -180,10 +124,13 @@ int main(int argc, char *argv[])
         localProxyMode = AWS_SECURE_TUNNELING_DESTINATION_MODE;
     }
 
-    if (s_cmdOptionExists(argv, argv + argc, "--message"))
-    {
-        message = s_getCmdOption(argv, argv + argc, "--message");
-    }
+    message = cmdUtils.GetCommandOrDefault("message", "Hello World");
+
+    /*
+     * For internal testing
+     */
+    bool isTest = cmdUtils.HasCommand("test");
+    int expectedMessageCount = 5;
 
     if (apiHandle.GetOrCreateStaticDefaultClientBootstrap()->LastError() != AWS_ERROR_SUCCESS)
     {
@@ -250,8 +197,8 @@ int main(int argc, char *argv[])
     };
 
     auto OnDataReceive = [&](const struct aws_byte_buf &data) {
-        string receivedData = std::string((char *)data.buffer, data.len);
-        string returnMessage = "Echo:" + receivedData;
+        String receivedData = String((char *)data.buffer, data.len);
+        String returnMessage = "Echo:" + receivedData;
 
         fprintf(stdout, "Received: \"%s\"\n", receivedData.c_str());
 
@@ -375,7 +322,7 @@ int main(int argc, char *argv[])
             if (localProxyMode == AWS_SECURE_TUNNELING_SOURCE_MODE)
             {
                 messageCount++;
-                string toSend = to_string(messageCount) + ": " + message.c_str();
+                String toSend = (std::to_string(messageCount) + ": " + message.c_str()).c_str();
 
                 if (!secureTunnel->SendData(ByteCursorFromCString(toSend.c_str())))
                 {
diff --git a/samples/secure_tunneling/tunnel_notification/CMakeLists.txt b/samples/secure_tunneling/tunnel_notification/CMakeLists.txt
index 1a12aa952..fd25af565 100644
--- a/samples/secure_tunneling/tunnel_notification/CMakeLists.txt
+++ b/samples/secure_tunneling/tunnel_notification/CMakeLists.txt
@@ -4,6 +4,8 @@ project(tunnel-notification CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/secure_tunneling/tunnel_notification/main.cpp b/samples/secure_tunneling/tunnel_notification/main.cpp
index 1c1e27303..9b7cf2c23 100644
--- a/samples/secure_tunneling/tunnel_notification/main.cpp
+++ b/samples/secure_tunneling/tunnel_notification/main.cpp
@@ -21,46 +21,14 @@
 #include <mutex>
 #include <thread>
 
+#include "../../utils/CommandLineUtils.h"
+
 using namespace std;
 using namespace Aws::Iot;
 using namespace Aws::Crt;
 using namespace Aws::Crt::Mqtt;
 using namespace Aws::Iotsecuretunneling;
 
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "tunnel-notification --endpoint <endpoint> --cert <path to cert>"
-        " --key <path to key> --ca_file <optional: path to custom ca>"
-        " --thing_name <thing name> \n\n");
-    fprintf(stdout, "endpoint: the endpoint of the mqtt server not including a port\n");
-    fprintf(stdout, "cert: path to your client certificate in PEM format\n");
-    fprintf(stdout, "key: path to your key in PEM format\n");
-    fprintf(
-        stdout,
-        "ca_file: Optional, if the mqtt server uses a certificate that's not already"
-        " in your trust store, set this.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "thing_name: the name of your IOT thing\n");
-}
-
-bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
-
 int main(int argc, char *argv[])
 {
     /************************ Setup the Lib ****************************/
@@ -77,22 +45,23 @@ int main(int argc, char *argv[])
     String thingName;
 
     /*********************** Parse Arguments ***************************/
-    if (!(s_cmdOptionExists(argv, argv + argc, "--endpoint") && s_cmdOptionExists(argv, argv + argc, "--cert") &&
-          s_cmdOptionExists(argv, argv + argc, "--key") && s_cmdOptionExists(argv, argv + argc, "--thing_name")))
-    {
-        s_printHelp();
-        return 0;
-    }
-
-    endpoint = s_getCmdOption(argv, argv + argc, "--endpoint");
-    certificatePath = s_getCmdOption(argv, argv + argc, "--cert");
-    keyPath = s_getCmdOption(argv, argv + argc, "--key");
-    thingName = s_getCmdOption(argv, argv + argc, "--thing_name");
-
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("tunnel_notification");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.RegisterCommand("thing_name", "<str>", "The name of your IOT thing");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
+    endpoint = cmdUtils.GetCommandRequired("endpoint");
+    certificatePath = cmdUtils.GetCommandRequired("cert");
+    keyPath = cmdUtils.GetCommandRequired("key");
+    thingName = cmdUtils.GetCommandRequired("thing_name");
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", caFile);
 
     /********************** Now Setup an Mqtt Client ******************/
     if (apiHandle.GetOrCreateStaticDefaultClientBootstrap()->LastError() != AWS_ERROR_SUCCESS)
diff --git a/samples/shadow/shadow_sync/CMakeLists.txt b/samples/shadow/shadow_sync/CMakeLists.txt
index 3bf5a5fcf..45c4e76eb 100644
--- a/samples/shadow/shadow_sync/CMakeLists.txt
+++ b/samples/shadow/shadow_sync/CMakeLists.txt
@@ -4,6 +4,8 @@ project(shadow-sync CXX)
 
 file(GLOB SRC_FILES
        "*.cpp"
+       "../../utils/CommandLineUtils.cpp"
+       "../../utils/CommandLineUtils.h"
 )
 
 add_executable(${PROJECT_NAME} ${SRC_FILES})
diff --git a/samples/shadow/shadow_sync/main.cpp b/samples/shadow/shadow_sync/main.cpp
index fbd825591..c537693d3 100644
--- a/samples/shadow/shadow_sync/main.cpp
+++ b/samples/shadow/shadow_sync/main.cpp
@@ -22,46 +22,13 @@
 #include <iostream>
 #include <mutex>
 
+#include "../../utils/CommandLineUtils.h"
+
 using namespace Aws::Crt;
 using namespace Aws::Iotshadow;
 
 static const char *SHADOW_VALUE_DEFAULT = "off";
 
-static void s_printHelp()
-{
-    fprintf(stdout, "Usage:\n");
-    fprintf(
-        stdout,
-        "shadow-sync --endpoint <endpoint> --cert <path to cert>"
-        " --key <path to key> --ca_file <optional: path to custom ca>"
-        " --thing_name <thing name> --shadow_property <Name of property in shadow to keep in sync.>\n\n");
-    fprintf(stdout, "endpoint: the endpoint of the mqtt server not including a port\n");
-    fprintf(stdout, "cert: path to your client certificate in PEM format\n");
-    fprintf(stdout, "key: path to your key in PEM format\n");
-    fprintf(
-        stdout,
-        "ca_file: Optional, if the mqtt server uses a certificate that's not already"
-        " in your trust store, set this.\n");
-    fprintf(stdout, "\tIt's the path to a CA file in PEM format\n");
-    fprintf(stdout, "thing_name: the name of your IOT thing\n");
-    fprintf(stdout, "shadow_property: The name of the shadow property you want to change.\n");
-}
-
-static bool s_cmdOptionExists(char **begin, char **end, const String &option)
-{
-    return std::find(begin, end, option) != end;
-}
-
-static char *s_getCmdOption(char **begin, char **end, const String &option)
-{
-    char **itr = std::find(begin, end, option);
-    if (itr != end && ++itr != end)
-    {
-        return *itr;
-    }
-    return 0;
-}
-
 static void s_changeShadowValue(
     IotShadowClient &client,
     const String &thingName,
@@ -130,24 +97,25 @@ int main(int argc, char *argv[])
     String clientId(String("test-") + Aws::Crt::UUID().ToString());
 
     /*********************** Parse Arguments ***************************/
-    if (!(s_cmdOptionExists(argv, argv + argc, "--endpoint") && s_cmdOptionExists(argv, argv + argc, "--cert") &&
-          s_cmdOptionExists(argv, argv + argc, "--key") && s_cmdOptionExists(argv, argv + argc, "--thing_name") &&
-          s_cmdOptionExists(argv, argv + argc, "--shadow_property")))
+    Utils::CommandLineUtils cmdUtils = Utils::CommandLineUtils();
+    cmdUtils.RegisterProgramName("shadow_sync");
+    cmdUtils.AddCommonMQTTCommands();
+    cmdUtils.RegisterCommand("thing_name", "<str>", "The name of your IOT thing.");
+    cmdUtils.RegisterCommand("shadow_property", "<str>", "The name of the shadow property you want to change.");
+    const char **const_argv = (const char **)argv;
+    cmdUtils.SendArguments(const_argv, const_argv + argc);
+
+    if (cmdUtils.HasCommand("help"))
     {
-        s_printHelp();
-        return 0;
-    }
-
-    endpoint = s_getCmdOption(argv, argv + argc, "--endpoint");
-    certificatePath = s_getCmdOption(argv, argv + argc, "--cert");
-    keyPath = s_getCmdOption(argv, argv + argc, "--key");
-    thingName = s_getCmdOption(argv, argv + argc, "--thing_name");
-    shadowProperty = s_getCmdOption(argv, argv + argc, "--shadow_property");
-
-    if (s_cmdOptionExists(argv, argv + argc, "--ca_file"))
-    {
-        caFile = s_getCmdOption(argv, argv + argc, "--ca_file");
+        cmdUtils.PrintHelp();
+        exit(-1);
     }
+    endpoint = cmdUtils.GetCommandRequired("endpoint");
+    certificatePath = cmdUtils.GetCommandRequired("cert");
+    keyPath = cmdUtils.GetCommandRequired("key");
+    thingName = cmdUtils.GetCommandRequired("thing_name");
+    shadowProperty = cmdUtils.GetCommandRequired("shadow_property");
+    caFile = cmdUtils.GetCommandOrDefault("ca_file", caFile);
 
     /********************** Now Setup an Mqtt Client ******************/
     if (apiHandle.GetOrCreateStaticDefaultClientBootstrap()->LastError() != AWS_ERROR_SUCCESS)
diff --git a/samples/utils/CommandLineUtils.cpp b/samples/utils/CommandLineUtils.cpp
new file mode 100644
index 000000000..6b17f52e7
--- /dev/null
+++ b/samples/utils/CommandLineUtils.cpp
@@ -0,0 +1,174 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+#include "CommandLineUtils.h"
+#include <aws/crt/Types.h>
+#include <iostream>
+
+namespace Utils
+{
+    void CommandLineUtils::RegisterProgramName(Aws::Crt::String newProgramName)
+    {
+        m_programName = std::move(newProgramName);
+    }
+
+    void CommandLineUtils::RegisterCommand(CommandLineOption option)
+    {
+        if (m_registeredCommands.count(option.m_commandName))
+        {
+            fprintf(stdout, "Cannot register command: %s: Command already registered!", option.m_commandName.c_str());
+            return;
+        }
+        m_registeredCommands.insert({option.m_commandName, option});
+    }
+
+    void CommandLineUtils::RegisterCommand(
+        Aws::Crt::String commandName,
+        Aws::Crt::String exampleInput,
+        Aws::Crt::String helpOutput)
+    {
+        RegisterCommand(CommandLineOption(commandName, exampleInput, helpOutput));
+    }
+
+    void CommandLineUtils::RemoveCommand(Aws::Crt::String commandName)
+    {
+        if (m_registeredCommands.count(commandName))
+        {
+            m_registeredCommands.erase(commandName);
+        }
+    }
+
+    void CommandLineUtils::UpdateCommandHelp(Aws::Crt::String commandName, Aws::Crt::String newCommandHelp)
+    {
+        if (m_registeredCommands.count(commandName))
+        {
+            m_registeredCommands.at(commandName).m_helpOutput = std::move(newCommandHelp);
+        }
+    }
+
+    void CommandLineUtils::SendArguments(const char **argv, const char **argc)
+    {
+        if (m_beginPosition != nullptr || m_endPosition != nullptr)
+        {
+            fprintf(stdout, "Arguments already sent!");
+            return;
+        }
+        m_beginPosition = argv;
+        m_endPosition = argc;
+    }
+
+    bool CommandLineUtils::HasCommand(Aws::Crt::String command)
+    {
+        return std::find(m_beginPosition, m_endPosition, "--" + command) != m_endPosition;
+    }
+
+    Aws::Crt::String CommandLineUtils::GetCommand(Aws::Crt::String command)
+    {
+        const char **itr = std::find(m_beginPosition, m_endPosition, "--" + command);
+        if (itr != m_endPosition && ++itr != m_endPosition)
+        {
+            return Aws::Crt::String(*itr);
+        }
+        return "";
+    }
+
+    Aws::Crt::String CommandLineUtils::GetCommandOrDefault(Aws::Crt::String command, Aws::Crt::String commandDefault)
+    {
+        if (HasCommand(command))
+        {
+            return Aws::Crt::String(GetCommand(command));
+        }
+        return commandDefault;
+    }
+
+    Aws::Crt::String CommandLineUtils::GetCommandRequired(
+        Aws::Crt::String command,
+        Aws::Crt::String optionalAdditionalMessage)
+    {
+        if (HasCommand(command))
+        {
+            return GetCommand(command);
+        }
+        PrintHelp();
+        fprintf(stderr, "Missing required argument: --%s\n", command.c_str());
+        if (optionalAdditionalMessage != "")
+        {
+            fprintf(stderr, "%s\n", optionalAdditionalMessage.c_str());
+        }
+        exit(-1);
+    }
+
+    void CommandLineUtils::PrintHelp()
+    {
+        fprintf(stdout, "Usage:\n");
+        fprintf(stdout, "%s", m_programName.c_str());
+
+        for (auto const &pair : m_registeredCommands)
+        {
+            fprintf(stdout, " --%s %s", pair.first.c_str(), pair.second.m_exampleInput.c_str());
+        }
+
+        fprintf(stdout, "\n\n");
+
+        for (auto const &pair : m_registeredCommands)
+        {
+            fprintf(stdout, "* %s:\t\t%s\n", pair.first.c_str(), pair.second.m_helpOutput.c_str());
+        }
+
+        fprintf(stdout, "\n");
+    }
+
+    void CommandLineUtils::AddCommonMQTTCommands()
+    {
+        RegisterCommand(
+            Utils::CommandLineOption("endpoint", "<str>", "The endpoint of the mqtt server not including a port."));
+        RegisterCommand(Utils::CommandLineOption("key", "<path>", "Path to your key in PEM format."));
+        RegisterCommand(Utils::CommandLineOption("cert", "<path>", "Path to your client certificate in PEM format."));
+        RegisterCommand(Utils::CommandLineOption(
+            "ca_file", "<path>", "Path to AmazonRootCA1.pem (optional, system trust store used by default)."));
+    }
+
+    void CommandLineUtils::AddCommonProxyCommands()
+    {
+        RegisterCommand("proxy_host", "<str>", "Host name of the proxy server to connect through (optional)");
+        RegisterCommand("proxy_port", "<int>", "Port of the proxy server to connect through (optional, default='8080'");
+    }
+
+    void CommandLineUtils::AddCommonX509Commands()
+    {
+        RegisterCommand("x509", "", "Use the x509 credentials provider while using websockets (optional)");
+        RegisterCommand(
+            "x509_role_alias", "<str>", "Role alias to use with the x509 credentials provider (required for x509)");
+        RegisterCommand("x509_endpoint", "<str>", "Endpoint to fetch x509 credentials from (required for x509)");
+        RegisterCommand("x509_thing", "<str>", "Thing name to fetch x509 credentials on behalf of (required for x509)");
+        RegisterCommand(
+            "x509_cert",
+            "<path>",
+            "Path to the IoT thing certificate used in fetching x509 credentials (required for x509)");
+        RegisterCommand(
+            "x509_key",
+            "<path>",
+            "Path to the IoT thing private key used in fetching x509 credentials (required for x509)");
+        RegisterCommand(
+            "x509_ca_file",
+            "<path>",
+            "Path to the root certificate used in fetching x509 credentials (required for x509)");
+    }
+
+    void CommandLineUtils::AddCommonTopicMessageCommands()
+    {
+        RegisterCommand("message", "<str>", "The message to send in the payload (optional, default='Hello world!')");
+        RegisterCommand("topic", "<str>", "Topic to publish, subscribe to. (optional, default='test/topic')");
+    }
+
+    void CommandLineUtils::AddCommonWebsocketCommands()
+    {
+        RegisterCommand("use_websocket", "", "If specified, uses a websocket over https (optional)");
+        RegisterCommand(
+            "signing_region",
+            "<str>",
+            "Used for websocket signer it should only be specific if websockets are used. (required for websockets)");
+    }
+
+} // namespace Utils
diff --git a/samples/utils/CommandLineUtils.h b/samples/utils/CommandLineUtils.h
new file mode 100644
index 000000000..cee09ec3f
--- /dev/null
+++ b/samples/utils/CommandLineUtils.h
@@ -0,0 +1,164 @@
+#pragma once
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+
+#include <aws/crt/Types.h>
+
+namespace Utils
+{
+    /**
+     * A struct to hold the command line options that can be passed to the program from the terminal/console.
+     */
+    struct CommandLineOption
+    {
+        Aws::Crt::String m_commandName;
+        Aws::Crt::String m_exampleInput;
+        Aws::Crt::String m_helpOutput;
+
+        CommandLineOption(
+            Aws::Crt::String inputName,
+            Aws::Crt::String inputExampleInput,
+            Aws::Crt::String inputHelp = "")
+        {
+            m_commandName = std::move(inputName);
+            m_exampleInput = std::move(inputExampleInput);
+            m_helpOutput = std::move(inputHelp);
+        }
+    };
+
+    /**
+     * A helper class that makes it easier to register, find, and parse commands passed to the program from the
+     * terminal/console.
+     */
+    class CommandLineUtils
+    {
+      public:
+        /**
+         * Changes the program name to the name given. The program name is shown when calling help and showing all the
+         * commands.
+         * @param newProgramName The program name to show when executing PrintHelp
+         */
+        void RegisterProgramName(Aws::Crt::String newProgramName);
+
+        /**
+         * Adds a new command to the utility. Used to show command data when printing all commands.
+         * @param newCommand The command struct containing the new command/argument data
+         */
+        void RegisterCommand(CommandLineOption newCommand);
+        /**
+         * Adds a new command to the utility. Used to show command data when printing all commands.
+         * @param commandName The name of the command
+         * @param exampleInput Example input for the command (example "<endpoint>")
+         * @param helpOutput The message to show with the command when printing all commands via help
+         */
+        void RegisterCommand(
+            Aws::Crt::String commandName,
+            Aws::Crt::String exampleInput,
+            Aws::Crt::String helpOutput = "");
+
+        /**
+         * Removes the command if it has already been registered
+         * @param commandName
+         */
+        void RemoveCommand(Aws::Crt::String commandName);
+
+        /**
+         * Updates the help text of a registered command. If the given command does not exist, nothing happens
+         * @param commandName The name of the command
+         * @param newCommandHelp
+         */
+        void UpdateCommandHelp(Aws::Crt::String commandName, Aws::Crt::String newCommandHelp);
+
+        /**
+         * Called to give the class a copy of the begin and end character pointers that contain the arguments from the
+         * terminal/console
+         * @param argv The beginning of terminal/console input
+         * @param argc The end of terminal/console input
+         */
+        void SendArguments(const char **argv, const char **argc);
+
+        /**
+         * Returns true if the command was inputted into the terminal/console
+         *
+         * You must call SendArguments and pass terminal/console input first in order for the function to work.
+         *
+         * @param CommandName The name of the command you are looking for
+         * @return true If the command is found
+         * @return false If the command is not found
+         */
+        bool HasCommand(Aws::Crt::String CommandName);
+
+        /**
+         * Gets the value of the command passed into the console/terminal. This function assumes the command exists
+         * and was passed into the program through the console/terminal.
+         *
+         * You must call SendArguments and pass console/terminal input first in order for the function to work.
+         *
+         * @param CommandName The name of the command you want to get the value of
+         * @return Aws::Crt::String The value passed into the program at the command name
+         */
+        Aws::Crt::String GetCommand(Aws::Crt::String CommandName);
+
+        /**
+         * Gets the value of the command passed into the console/terminal if it exists, otherwise it returns
+         * whatever value is appsed into CommandDefault
+         *
+         * You must call SendArguments and pass console/terminal input first in order for the function to work.
+         *
+         * @param CommandName The name of the command you want to get the value of
+         * @param CommandDefault The value to assign if the command does not exist
+         * @return Aws::Crt::String The value passed into the program at the command name
+         */
+        Aws::Crt::String GetCommandOrDefault(Aws::Crt::String CommandName, Aws::Crt::String CommandDefault);
+
+        /**
+         * Gets the value of the command passed into the console/terminal if it exists. If it does not exist,
+         * the program will exit with an error message.
+         *
+         * @param CommandName The name of the command you want to get the value of
+         * @return Aws::Crt::String The value passed into the program at the command name
+         */
+        Aws::Crt::String GetCommandRequired(
+            Aws::Crt::String CommandName,
+            Aws::Crt::String OptionalAdditionalMessage = "");
+
+        /**
+         * Prints to the console/terminal all of the commands and their descriptions.
+         */
+        void PrintHelp();
+
+        /**
+         * A helper function that adds endpoint, key, cert, and ca_file commands
+         */
+        void AddCommonMQTTCommands();
+
+        /**
+         * A helper function that adds proxy_port, proxy_username, proxy_password, and proxy_host commands.
+         */
+        void AddCommonProxyCommands();
+
+        /**
+         * A helper function that adds x509, x509_role_alias, x509_endpoint, x509_thing, x509_cert,
+         * x509_key, and x509_ca_file commands
+         */
+        void AddCommonX509Commands();
+
+        /**
+         * A helper function that adds topic and message commands
+         */
+        void AddCommonTopicMessageCommands();
+
+        /**
+         * A helper function that adds use_websocket and signing_region
+         */
+        void AddCommonWebsocketCommands();
+
+      private:
+        Aws::Crt::String m_programName = "Application";
+        const char **m_beginPosition = nullptr;
+        const char **m_endPosition = nullptr;
+        Aws::Crt::Map<Aws::Crt::String, CommandLineOption> m_registeredCommands;
+    };
+} // namespace Utils