Fix show fsdb subscribers to handle patch subs

Summary:
For patch subscribers, in OperSubscriberInfo optional path and extendedPaths
would not present. Add check to ensure that "fboss2 show fsdb subscribers"
doesn't crash in this case.

Reviewed By: wilsonwinhi

Differential Revision: D60996692

fbshipit-source-id: b521e4a360e865918d9d8fa63b88d90c376f771e

fboss/cli/fboss2/utils/CmdUtils.cpp

@@ -242,7 +242,10 @@ std::optional<std::string> getMyHostname(const std::string& hostname) {
 }
 
 std::string escapeDoubleQuotes(const std::string& cmd) {
-  return std::regex_replace(cmd, std::regex("\""), "\\\"");
+  std::string cmdCopy = cmd;
+  const re2::RE2 doubleQuotes("\"");
+  re2::RE2::Replace(&cmdCopy, doubleQuotes, "\\\"");
+  return cmdCopy;
 }
 
 std::string getCmdToRun(const std::string& hostname, const std::string& cmd) {
@@ -293,18 +296,26 @@ std::string getSubscriptionPathStr(const fsdb::OperSubscriberInfo& subscriber) {
     return folly::join("/", subscriber.get_path()->get_raw());
   }
   std::vector<std::string> extPaths;
-  for (const auto& extPath : *subscriber.get_extendedPaths()) {
-    std::vector<std::string> pathElements;
-    for (const auto& pathElm : *extPath.path()) {
-      if (pathElm.any_ref().has_value()) {
-        pathElements.push_back("*");
-      } else if (pathElm.regex_ref().has_value()) {
-        pathElements.push_back(*pathElm.regex_ref());
-      } else {
-        pathElements.push_back(*pathElm.raw_ref());
+  if (auto subExtPaths = subscriber.get_extendedPaths()) {
+    for (const auto& extPath : *subExtPaths) {
+      std::vector<std::string> pathElements;
+      for (const auto& pathElm : *extPath.path()) {
+        if (pathElm.any_ref().has_value()) {
+          pathElements.push_back("*");
+        } else if (pathElm.regex_ref().has_value()) {
+          pathElements.push_back(*pathElm.regex_ref());
+        } else {
+          pathElements.push_back(*pathElm.raw_ref());
+        }
       }
+      extPaths.push_back(folly::join("/", pathElements));
+    }
+  }
+  auto paths = subscriber.get_paths();
+  if (paths) {
+    for (const auto& path : *paths) {
+      extPaths.push_back(folly::join("/", path.second.get_path()));
     }
-    extPaths.push_back(folly::join("/", pathElements));
   }
   return folly::join(";", extPaths);
 }