diff --git a/samples/web-app-file-storage/dotnet/scripts/00-variables.sh b/samples/web-app-file-storage/dotnet/scripts/00-variables.sh
index 938e702..f22632e 100755
--- a/samples/web-app-file-storage/dotnet/scripts/00-variables.sh
+++ b/samples/web-app-file-storage/dotnet/scripts/00-variables.sh
@@ -1,11 +1,21 @@
 # Variables
 
+# Lowercase and uppercase conversions that also run on bash 3.2, the /bin/bash of macOS: the
+# ${value,,} and ${value^^} expansions need bash 4 and fail there with "bad substitution".
+lowercase() {
+	printf '%s' "$1" | tr '[:upper:]' '[:lower:]'
+}
+
+uppercase() {
+	printf '%s' "$1" | tr '[:lower:]' '[:upper:]'
+}
+
 # Azure Resources
 PREFIX='local'
 SUFFIX='test'
 LOCATION='italynorth'
 RESOURCE_GROUP_NAME="${PREFIX}-rg"
-ACR_NAME="${PREFIX,,}acr${SUFFIX,,}"
+ACR_NAME="$(lowercase "$PREFIX")acr$(lowercase "$SUFFIX")"
 ACR_SKU='Standard'
 AKS_CLUSTER_NAME="${PREFIX}-aks-${SUFFIX}"
 SUBSCRIPTION_NAME=$(az account show --query name --output tsv)
diff --git a/samples/web-app-file-storage/dotnet/scripts/01-deploy-resources.sh b/samples/web-app-file-storage/dotnet/scripts/01-deploy-resources.sh
index 68d94db..c951678 100755
--- a/samples/web-app-file-storage/dotnet/scripts/01-deploy-resources.sh
+++ b/samples/web-app-file-storage/dotnet/scripts/01-deploy-resources.sh
@@ -42,7 +42,7 @@ if [[ -z "$PROVISIONING_MODE" ]]; then
 	done
 fi
 
-PROVISIONING_MODE="${PROVISIONING_MODE,,}"
+PROVISIONING_MODE="$(lowercase "$PROVISIONING_MODE")"
 
 if [[ "$PROVISIONING_MODE" != 'static' && "$PROVISIONING_MODE" != 'dynamic' ]]; then
 	echo "Invalid provisioning mode [$PROVISIONING_MODE]: expected [static] or [dynamic]"
@@ -80,7 +80,7 @@ if [[ -z "$FILE_SHARE_PROTOCOL" ]]; then
 	done
 fi
 
-FILE_SHARE_PROTOCOL="${FILE_SHARE_PROTOCOL,,}"
+FILE_SHARE_PROTOCOL="$(lowercase "$FILE_SHARE_PROTOCOL")"
 
 if [[ "$FILE_SHARE_PROTOCOL" != 'smb' && "$FILE_SHARE_PROTOCOL" != 'nfs' ]]; then
 	echo "Invalid file share protocol [$FILE_SHARE_PROTOCOL]: expected [smb] or [nfs]"
@@ -104,7 +104,7 @@ else
 	exit 1
 fi
 
-echo "Deploying the resources for [$PROVISIONING_MODE] provisioning over [${FILE_SHARE_PROTOCOL^^}]..."
+echo "Deploying the resources for [$PROVISIONING_MODE] provisioning over [$(uppercase "$FILE_SHARE_PROTOCOL")]..."
 
 # Create a resource group
 echo "Checking if resource group [$RESOURCE_GROUP_NAME] exists in the subscription [$SUBSCRIPTION_NAME]..."
diff --git a/samples/web-app-file-storage/dotnet/scripts/04-push-docker-image.sh b/samples/web-app-file-storage/dotnet/scripts/04-push-docker-image.sh
index a1b7518..c9cdf75 100755
--- a/samples/web-app-file-storage/dotnet/scripts/04-push-docker-image.sh
+++ b/samples/web-app-file-storage/dotnet/scripts/04-push-docker-image.sh
@@ -20,7 +20,7 @@ fi
 FULL_IMAGE="${ACR_LOGIN_SERVER}/${IMAGE_NAME}:${IMAGE_TAG}"
 
 # Tag the local image with the loginServer of ACR
-docker tag ${IMAGE_NAME,,}:$IMAGE_TAG $ACR_LOGIN_SERVER/${IMAGE_NAME,,}:$IMAGE_TAG
+docker tag $(lowercase "$IMAGE_NAME"):$IMAGE_TAG $ACR_LOGIN_SERVER/$(lowercase "$IMAGE_NAME"):$IMAGE_TAG
 
 if [ $? -eq 0 ]; then
 	echo "Docker image [$IMAGE_NAME] tagged as [$FULL_IMAGE] successfully."
@@ -30,7 +30,7 @@ else
 fi
 
 # Push the container image to ACR
-docker push $ACR_LOGIN_SERVER/${IMAGE_NAME,,}:$IMAGE_TAG
+docker push $ACR_LOGIN_SERVER/$(lowercase "$IMAGE_NAME"):$IMAGE_TAG
 
 if [ $? -eq 0 ]; then
 	echo "Docker image [$FULL_IMAGE] pushed to ACR successfully."
diff --git a/samples/web-app-file-storage/dotnet/scripts/05-deploy-app.sh b/samples/web-app-file-storage/dotnet/scripts/05-deploy-app.sh
index 2addd08..37422c8 100755
--- a/samples/web-app-file-storage/dotnet/scripts/05-deploy-app.sh
+++ b/samples/web-app-file-storage/dotnet/scripts/05-deploy-app.sh
@@ -26,7 +26,7 @@ if [[ "$FILE_SHARE_PROTOCOL" != 'smb' && "$FILE_SHARE_PROTOCOL" != 'nfs' ]]; the
 	exit 1
 fi
 
-echo "Deploying the app with [$PROVISIONING_MODE] provisioning over [${FILE_SHARE_PROTOCOL^^}]..."
+echo "Deploying the app with [$PROVISIONING_MODE] provisioning over [$(uppercase "$FILE_SHARE_PROTOCOL")]..."
 
 # Pick the storage account that holds the file share for the selected protocol
 if [[ "$FILE_SHARE_PROTOCOL" == 'nfs' ]]; then
diff --git a/samples/web-app-file-storage/python/scripts/00-variables.sh b/samples/web-app-file-storage/python/scripts/00-variables.sh
index 4138fe6..b84f0cb 100755
--- a/samples/web-app-file-storage/python/scripts/00-variables.sh
+++ b/samples/web-app-file-storage/python/scripts/00-variables.sh
@@ -1,11 +1,21 @@
 # Variables
 
+# Lowercase and uppercase conversions that also run on bash 3.2, the /bin/bash of macOS: the
+# ${value,,} and ${value^^} expansions need bash 4 and fail there with "bad substitution".
+lowercase() {
+	printf '%s' "$1" | tr '[:upper:]' '[:lower:]'
+}
+
+uppercase() {
+	printf '%s' "$1" | tr '[:lower:]' '[:upper:]'
+}
+
 # Azure Resources
 PREFIX='local'
 SUFFIX='test'
 LOCATION='italynorth'
 RESOURCE_GROUP_NAME="${PREFIX}-rg"
-ACR_NAME="${PREFIX,,}acr${SUFFIX,,}"
+ACR_NAME="$(lowercase "$PREFIX")acr$(lowercase "$SUFFIX")"
 ACR_SKU='Standard'
 AKS_CLUSTER_NAME="${PREFIX}-aks-${SUFFIX}"
 SUBSCRIPTION_NAME=$(az account show --query name --output tsv)
diff --git a/samples/web-app-file-storage/python/scripts/01-deploy-resources.sh b/samples/web-app-file-storage/python/scripts/01-deploy-resources.sh
index 68d94db..c951678 100755
--- a/samples/web-app-file-storage/python/scripts/01-deploy-resources.sh
+++ b/samples/web-app-file-storage/python/scripts/01-deploy-resources.sh
@@ -42,7 +42,7 @@ if [[ -z "$PROVISIONING_MODE" ]]; then
 	done
 fi
 
-PROVISIONING_MODE="${PROVISIONING_MODE,,}"
+PROVISIONING_MODE="$(lowercase "$PROVISIONING_MODE")"
 
 if [[ "$PROVISIONING_MODE" != 'static' && "$PROVISIONING_MODE" != 'dynamic' ]]; then
 	echo "Invalid provisioning mode [$PROVISIONING_MODE]: expected [static] or [dynamic]"
@@ -80,7 +80,7 @@ if [[ -z "$FILE_SHARE_PROTOCOL" ]]; then
 	done
 fi
 
-FILE_SHARE_PROTOCOL="${FILE_SHARE_PROTOCOL,,}"
+FILE_SHARE_PROTOCOL="$(lowercase "$FILE_SHARE_PROTOCOL")"
 
 if [[ "$FILE_SHARE_PROTOCOL" != 'smb' && "$FILE_SHARE_PROTOCOL" != 'nfs' ]]; then
 	echo "Invalid file share protocol [$FILE_SHARE_PROTOCOL]: expected [smb] or [nfs]"
@@ -104,7 +104,7 @@ else
 	exit 1
 fi
 
-echo "Deploying the resources for [$PROVISIONING_MODE] provisioning over [${FILE_SHARE_PROTOCOL^^}]..."
+echo "Deploying the resources for [$PROVISIONING_MODE] provisioning over [$(uppercase "$FILE_SHARE_PROTOCOL")]..."
 
 # Create a resource group
 echo "Checking if resource group [$RESOURCE_GROUP_NAME] exists in the subscription [$SUBSCRIPTION_NAME]..."
diff --git a/samples/web-app-file-storage/python/scripts/04-push-docker-image.sh b/samples/web-app-file-storage/python/scripts/04-push-docker-image.sh
index a1b7518..c9cdf75 100755
--- a/samples/web-app-file-storage/python/scripts/04-push-docker-image.sh
+++ b/samples/web-app-file-storage/python/scripts/04-push-docker-image.sh
@@ -20,7 +20,7 @@ fi
 FULL_IMAGE="${ACR_LOGIN_SERVER}/${IMAGE_NAME}:${IMAGE_TAG}"
 
 # Tag the local image with the loginServer of ACR
-docker tag ${IMAGE_NAME,,}:$IMAGE_TAG $ACR_LOGIN_SERVER/${IMAGE_NAME,,}:$IMAGE_TAG
+docker tag $(lowercase "$IMAGE_NAME"):$IMAGE_TAG $ACR_LOGIN_SERVER/$(lowercase "$IMAGE_NAME"):$IMAGE_TAG
 
 if [ $? -eq 0 ]; then
 	echo "Docker image [$IMAGE_NAME] tagged as [$FULL_IMAGE] successfully."
@@ -30,7 +30,7 @@ else
 fi
 
 # Push the container image to ACR
-docker push $ACR_LOGIN_SERVER/${IMAGE_NAME,,}:$IMAGE_TAG
+docker push $ACR_LOGIN_SERVER/$(lowercase "$IMAGE_NAME"):$IMAGE_TAG
 
 if [ $? -eq 0 ]; then
 	echo "Docker image [$FULL_IMAGE] pushed to ACR successfully."
diff --git a/samples/web-app-file-storage/python/scripts/05-deploy-app.sh b/samples/web-app-file-storage/python/scripts/05-deploy-app.sh
index a4772d3..f18a1f6 100755
--- a/samples/web-app-file-storage/python/scripts/05-deploy-app.sh
+++ b/samples/web-app-file-storage/python/scripts/05-deploy-app.sh
@@ -26,7 +26,7 @@ if [[ "$FILE_SHARE_PROTOCOL" != 'smb' && "$FILE_SHARE_PROTOCOL" != 'nfs' ]]; the
 	exit 1
 fi
 
-echo "Deploying the app with [$PROVISIONING_MODE] provisioning over [${FILE_SHARE_PROTOCOL^^}]..."
+echo "Deploying the app with [$PROVISIONING_MODE] provisioning over [$(uppercase "$FILE_SHARE_PROTOCOL")]..."
 
 # Pick the storage account that holds the file share for the selected protocol
 if [[ "$FILE_SHARE_PROTOCOL" == 'nfs' ]]; then