Update S3 Sample (#321)

README.md

@@ -68,6 +68,23 @@ cmake -S aws-c-s3 -B aws-c-s3/build -DCMAKE_INSTALL_PREFIX=<install-path> -DCMAK
 cmake --build aws-c-s3/build --target install
 ```
 
+#### Running S3 sample
+
+After installing all the dependencies, and building aws-c-s3, you can run the sample directly from the s3 build directory.
+
+To download:
+```
+aws-c-s3/build/samples/s3/s3 cp s3://<bucket-name>/<object-name> <download-path> --region <region>
+```
+To upload:
+```
+aws-c-s3/build/samples/s3/s3 cp <upload-path> s3://<bucket-name>/<object-name> --region <region>
+```
+To list objects:
+```
+aws-c-s3/build/samples/s3/s3 ls s3://<bucket-name> --region <region>
+```
+
 ## Testing
 
 The unit tests require an AWS account with S3 buckets set up in a particular way.

samples/s3/s3-cp.c

@@ -811,10 +811,16 @@ static bool s_are_all_transfers_and_listings_done(void *arg) {
 }
 
 void s_on_object_list_finished(struct aws_s3_paginator *paginator, int error_code, void *user_data) {
-    (void)error_code;
 
     struct cp_app_ctx *cp_app_ctx = user_data;
-
+    if (error_code != AWS_OP_SUCCESS) {
+        fprintf(
+            stderr,
+            "Failure while listing objects. Please check if you have valid credentials and s3 path is correct. Error: "
+            "%s\n",
+            aws_error_debug_str(error_code));
+        exit(1);
+    }
     if (aws_s3_paginator_has_more_results(paginator)) {
         aws_s3_paginator_continue(paginator, &cp_app_ctx->app_ctx->signing_config);
     } else {

samples/s3/s3-ls.c

@@ -114,6 +114,13 @@ void s_on_list_finished(struct aws_s3_paginator *paginator, int error_code, void
             }
             return;
         }
+    } else {
+        fprintf(
+            stderr,
+            "Failure while listing objects. Please check if you have valid credentials and s3 path is correct. "
+            "Error: "
+            "%s\n",
+            aws_error_debug_str(error_code));
     }
 
     /* all pages received. triggers the condition variable to exit the application. */