Update crate_feature_finder.sh

Author: DocDBrown

crate_feature_finder.sh

@@ -20,13 +20,9 @@ fetch_json() {
 	# Use -s for silent, --max-time for timeout
 	# -w "\n%{http_code}" appends the HTTP status code on a new line to stdout.
 	# This helps in reliably separating the body from the status code.
-	response_and_status=$(curl -s --max-time 10 -w "\n%{http_code}" "$url" 2>/dev/null)
-	local curl_exit=$?
-
-	# Check if curl command itself failed (e.g., network error, timeout before HTTP response)
-	if [[ $curl_exit -ne 0 ]]; then
+	if ! response_and_status=$(curl -s --max-time 10 -w $'\n%{http_code}' "$url" 2>/dev/null); then
 		echo "Error: curl command failed for $url" >&2
-		return 1 # Indicate failure
+		return 1
 	fi
 
 	# Ensure we have some output to parse
@@ -35,48 +31,45 @@ fetch_json() {
 		return 1
 	fi
 
-	# Split the response into body and status code based on the newline added by -w
-	# The last line is the status code, everything before it is the body.
-	http_status=$(echo -n "$response_and_status" | tail -n 1)
-	response_body=$(echo -n "$response_and_status" | head -n -1)
+	# Split response into body and status code using bash string ops (portable across GNU/BSD).
+	http_status="${response_and_status##*$'\n'}"
+	response_body="${response_and_status%$'\n'*}"
 
 	# Handle 2xx success, 404 as handled empty, and other statuses as errors.
 	if [[ "$http_status" =~ ^2[0-9][0-9]$ ]]; then
-		echo "$response_body"
+		printf '%s' "$response_body"
 		sleep "$REQUEST_DELAY" # Be polite
 		return 0
 	elif [[ "$http_status" == "404" ]]; then
 		# Crate or version not found. This is a handled case, not necessarily an error for the script's logic.
-		echo ""
+		printf '%s' ""
 		sleep "$REQUEST_DELAY"
 		return 0
 	else
 		echo "Error: Failed to fetch $url. HTTP Status: $http_status. Response: ${response_body:0:100}..." >&2
-		return 1 # Indicate failure
+		return 1
 	fi
 }
 
 # Only run main when executed directly, not when sourced by tests
 if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
 	# Main script logic
-	if [[ "\$#" -eq 0 ]]; then
+	if [[ $# -eq 0 ]]; then
 		echo "Usage: $0 <crate_name_1> [crate_name_2] ..." >&2
 		exit 1
 	fi
 
-	for crate_name in "\$@"; do
+	for crate_name in "$@"; do
 		# 1. Try to get max_version from /api/v1/crates/{name}
 		CRATE_INFO_URL="${CRATES_IO_API_BASE}/crates/${crate_name}"
-		crate_info_json=$(fetch_json "$CRATE_INFO_URL")
-
-		if [[ $? -ne 0 ]]; then # Check if fetch_json itself failed (e.g., curl error)
+		if ! crate_info_json=$(fetch_json "$CRATE_INFO_URL"); then
 			echo "Skipping '$crate_name': Failed to retrieve crate info due to network/curl error." >&2
 			continue
 		fi
 
 		target_version=""
 		if [[ -n "$crate_info_json" ]]; then
-			max_version=$(echo "$crate_info_json" | jq -r '.crate.max_version // empty')
+			max_version=$(printf '%s' "$crate_info_json" | jq -r '.crate.max_version // empty')
 			if [[ -n "$max_version" ]]; then
 				target_version="$max_version"
 			fi
@@ -85,16 +78,14 @@ if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
 		if [[ -z "$target_version" ]]; then
 			# 2. If max_version is empty or not found, fetch all versions and pick the first non-yanked one
 			VERSIONS_URL="${CRATES_IO_API_BASE}/crates/${crate_name}/versions"
-			versions_json=$(fetch_json "$VERSIONS_URL")
-
-			if [[ $? -ne 0 ]]; then
+			if ! versions_json=$(fetch_json "$VERSIONS_URL"); then
 				echo "Skipping '$crate_name': Failed to retrieve versions list due to network/curl error." >&2
 				continue
 			fi
 
 			if [[ -n "$versions_json" ]]; then
 				# Find the first non-yanked version number
-				target_version=$(echo "$versions_json" | jq -r '.versions[] | select(.yanked == false) | .num' | head -n 1)
+				target_version=$(printf '%s' "$versions_json" | jq -r '.versions[] | select(.yanked == false) | .num' | head -n 1)
 			fi
 
 			if [[ -z "$target_version" ]]; then
@@ -105,9 +96,7 @@ if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
 
 		# 3. Now that we have a target_version, fetch its metadata and check features
 		VERSION_METADATA_URL="${CRATES_IO_API_BASE}/crates/${crate_name}/${target_version}"
-		version_metadata_json=$(fetch_json "$VERSION_METADATA_URL")
-
-		if [[ $? -ne 0 ]]; then
+		if ! version_metadata_json=$(fetch_json "$VERSION_METADATA_URL"); then
 			echo "Skipping '$crate_name': Failed to retrieve metadata for version '$target_version' due to network/curl error." >&2
 			continue
 		fi
@@ -118,7 +107,7 @@ if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
 		fi
 
 		# Check if the features map is non-empty
-		feature_count=$(echo "$version_metadata_json" | jq -r '.version.features | to_entries | length // 0')
+		feature_count=$(printf '%s' "$version_metadata_json" | jq -r '.version.features | to_entries | length // 0')
 
 		if [[ "$feature_count" -gt 0 ]]; then
 			echo "$crate_name"