diff --git a/src/cache.cpp b/src/cache.cpp
index 22417f7..74ef968 100644
--- a/src/cache.cpp
+++ b/src/cache.cpp
@@ -255,10 +255,10 @@ bool StatCache::GetStat(string& key, struct stat* pst, headers_t* meta, bool ove
       string stretag;
       if(petag){
         // find & check ETag
-        for(headers_t::iterator iter = ent->meta.begin(); iter != ent->meta.end(); ++iter){
-          string tag = lower(iter->first);
+        for(headers_t::iterator hiter = ent->meta.begin(); hiter != ent->meta.end(); ++hiter){
+          string tag = lower(hiter->first);
           if(tag == "etag"){
-            stretag = iter->second;
+            stretag = hiter->second;
             if('\0' != petag[0] && 0 != strcmp(petag, stretag.c_str())){
               is_delete_cache = true;
             }
diff --git a/src/common.h b/src/common.h
index c141774..7b2e0bc 100644
--- a/src/common.h
+++ b/src/common.h
@@ -158,6 +158,7 @@ typedef std::map<std::string, PXATTRVAL> xattrs_t;
 //
 // Global variables
 //
+// TODO: namespace these
 extern bool           foreground;
 extern bool           nomultipart;
 extern bool           pathrequeststyle;
diff --git a/src/curl.cpp b/src/curl.cpp
index db82cee..5457671 100644
--- a/src/curl.cpp
+++ b/src/curl.cpp
@@ -103,21 +103,21 @@ static string url_to_host(const std::string &url)
 
   static const string http = "http://";
   static const string https = "https://";
-  std::string host;
+  std::string hostname;
 
   if (url.compare(0, http.size(), http) == 0) {
-    host = url.substr(http.size());
+    hostname = url.substr(http.size());
   } else if (url.compare(0, https.size(), https) == 0) {
-    host = url.substr(https.size());
+    hostname = url.substr(https.size());
   } else {
     assert(!"url does not begin with http:// or https://");
   }
 
   size_t idx;
-  if ((idx = host.find('/')) != string::npos) {
-    return host.substr(0, idx);
+  if ((idx = hostname.find('/')) != string::npos) {
+    return hostname.substr(0, idx);
   } else {
-    return host;
+    return hostname;
   }
 }
 
@@ -3904,24 +3904,23 @@ int S3fsMultiCurl::MultiPerform(void)
   bool                     success = true;
   bool                     isMultiHead = false;
   Semaphore                sem(S3fsCurl::max_parallel_cnt);
+  int                      rc;
 
   for(s3fscurlmap_t::iterator iter = cMap_req.begin(); iter != cMap_req.end(); ++iter) {
     pthread_t   thread;
     S3fsCurl*   s3fscurl = (*iter).second;
-    int         rc;
     s3fscurl->sem = &sem;
 
     sem.wait();
 
 #ifndef __APPLE__
     // macOS does not support pthread_tryjoin_np so we do not eagerly reap threads
-    for (std::vector<pthread_t>::iterator iter = threads.begin(); iter != threads.end(); ++iter) {
+    for (std::vector<pthread_t>::iterator titer = threads.begin(); titer != threads.end(); ++titer) {
       void*   retval;
-      int     rc;
 
-      rc = pthread_tryjoin_np(*iter, &retval);
+      rc = pthread_tryjoin_np(*titer, &retval);
       if (rc == 0) {
-        iter = threads.erase(iter);
+        titer = threads.erase(titer);
         int int_retval = (int)(intptr_t)(retval);
         if (int_retval && !(int_retval == -ENOENT && isMultiHead)) {
           S3FS_PRN_WARN("thread failed - rc(%d)", int_retval);
@@ -3930,7 +3929,7 @@ int S3fsMultiCurl::MultiPerform(void)
       } else if (rc == EBUSY) {
         continue;
       } else {
-        iter = threads.erase(iter);
+        titer = threads.erase(titer);
         success = false;
         S3FS_PRN_ERR("failed pthread_tryjoin_np - rc(%d)", rc);
       }
@@ -3960,11 +3959,10 @@ int S3fsMultiCurl::MultiPerform(void)
   }
 #endif
 
-  for (std::vector<pthread_t>::iterator iter = threads.begin(); iter != threads.end(); ++iter) {
+  for (std::vector<pthread_t>::iterator titer = threads.begin(); titer != threads.end(); ++titer) {
     void*   retval;
-    int     rc;
 
-    rc = pthread_join(*iter, &retval);
+    rc = pthread_join(*titer, &retval);
     if (rc) {
       success = false;
       S3FS_PRN_ERR("failed pthread_join - rc(%d)", rc);
@@ -4308,7 +4306,7 @@ string prepare_url(const char* url)
   S3FS_PRN_INFO3("URL is %s", url);
 
   string uri;
-  string host;
+  string hostname;
   string path;
   string url_str = string(url);
   string token = string("/") + bucket;
@@ -4324,10 +4322,10 @@ string prepare_url(const char* url)
   uri  = url_str.substr(0, uri_length);
 
   if(!pathrequeststyle){
-    host = bucket + "." + url_str.substr(uri_length, bucket_pos - uri_length).c_str();
+    hostname = bucket + "." + url_str.substr(uri_length, bucket_pos - uri_length).c_str();
     path = url_str.substr((bucket_pos + bucket_length));
   }else{
-    host = url_str.substr(uri_length, bucket_pos - uri_length).c_str();
+    hostname = url_str.substr(uri_length, bucket_pos - uri_length).c_str();
     string part = url_str.substr((bucket_pos + bucket_length));
     if('/' != part[0]){
       part = "/" + part;
@@ -4335,7 +4333,7 @@ string prepare_url(const char* url)
     path = "/" + bucket + part;
   }
 
-  url_str = uri + host + path;
+  url_str = uri + hostname + path;
 
   S3FS_PRN_INFO3("URL changed is %s", url_str.c_str());
 
diff --git a/src/fdcache.cpp b/src/fdcache.cpp
index 8601871..0572c7f 100644
--- a/src/fdcache.cpp
+++ b/src/fdcache.cpp
@@ -1808,11 +1808,11 @@ bool FdManager::DeleteCacheDirectory(void)
   if(0 == FdManager::cache_dir.size()){
     return true;
   }
-  string cache_dir;
-  if(!FdManager::MakeCachePath(NULL, cache_dir, false)){
+  string cache_path;
+  if(!FdManager::MakeCachePath(NULL, cache_path, false)){
     return false;
   }
-  return delete_files_in_dir(cache_dir.c_str(), true);
+  return delete_files_in_dir(cache_path.c_str(), true);
 }
 
 int FdManager::DeleteCacheFile(const char* path)
diff --git a/src/nss_auth.cpp b/src/nss_auth.cpp
index 4f02ca5..8e1e41e 100644
--- a/src/nss_auth.cpp
+++ b/src/nss_auth.cpp
@@ -96,7 +96,6 @@ static bool s3fs_HMAC_RAW(const void* key, size_t keylen, const unsigned char* d
   PK11SlotInfo* Slot;
   PK11SymKey*   pKey;
   PK11Context*  Context;
-  SECStatus     SecStatus;
   unsigned char tmpdigest[64];
   SECItem       KeySecItem   = {siBuffer, reinterpret_cast<unsigned char*>(const_cast<void*>(key)), static_cast<unsigned int>(keylen)};
   SECItem       NullSecItem  = {siBuffer, NULL, 0};
@@ -115,9 +114,9 @@ static bool s3fs_HMAC_RAW(const void* key, size_t keylen, const unsigned char* d
   }
 
   *digestlen = 0;
-  if(SECSuccess != (SecStatus = PK11_DigestBegin(Context)) ||
-     SECSuccess != (SecStatus = PK11_DigestOp(Context, data, datalen)) ||
-     SECSuccess != (SecStatus = PK11_DigestFinal(Context, tmpdigest, digestlen, sizeof(tmpdigest))) )
+  if(SECSuccess != PK11_DigestBegin(Context) ||
+     SECSuccess != PK11_DigestOp(Context, data, datalen) ||
+     SECSuccess != PK11_DigestFinal(Context, tmpdigest, digestlen, sizeof(tmpdigest)) )
   {
     PK11_DestroyContext(Context, PR_TRUE);
     PK11_FreeSymKey(pKey);
diff --git a/src/s3fs.cpp b/src/s3fs.cpp
index 5a8dc11..cc18867 100644
--- a/src/s3fs.cpp
+++ b/src/s3fs.cpp
@@ -2915,7 +2915,7 @@ static size_t parse_xattrs(const std::string& strxattrs, xattrs_t& xattrs)
   // get from "{" to "}"
   string restxattrs;
   {
-    size_t startpos = string::npos;
+    size_t startpos;
     size_t endpos   = string::npos;
     if(string::npos != (startpos = jsonxattrs.find_first_of("{"))){
       endpos = jsonxattrs.find_last_of("}");
@@ -3223,9 +3223,9 @@ static int s3fs_listxattr(const char* path, char* list, size_t size)
 
   // calculate total name length
   size_t total = 0;
-  for(xattrs_t::const_iterator iter = xattrs.begin(); iter != xattrs.end(); ++iter){
-    if(0 < iter->first.length()){
-      total += iter->first.length() + 1;
+  for(xattrs_t::const_iterator xiter = xattrs.begin(); xiter != xattrs.end(); ++xiter){
+    if(0 < xiter->first.length()){
+      total += xiter->first.length() + 1;
     }
   }
 
@@ -3246,9 +3246,9 @@ static int s3fs_listxattr(const char* path, char* list, size_t size)
 
   // copy to list
   char* setpos = list;
-  for(xattrs_t::const_iterator iter = xattrs.begin(); iter != xattrs.end(); ++iter){
-    if(0 < iter->first.length()){
-      strcpy(setpos, iter->first.c_str());
+  for(xattrs_t::const_iterator xiter = xattrs.begin(); xiter != xattrs.end(); ++xiter){
+    if(0 < xiter->first.length()){
+      strcpy(setpos, xiter->first.c_str());
       setpos = &setpos[strlen(setpos) + 1];
     }
   }
@@ -3887,28 +3887,28 @@ static int parse_passwd_file(bucketkvmap_t& resmap)
     if(first_pos == string::npos){
       continue;
     }
-    string bucket;
+    string bucketname;
     string accesskey;
     string secret;
     if(first_pos != last_pos){
       // formatted by "bucket:accesskey:secretkey"
-      bucket    = trim(iter->substr(0, first_pos));
+      bucketname    = trim(iter->substr(0, first_pos));
       accesskey = trim(iter->substr(first_pos + 1, last_pos - first_pos - 1));
       secret    = trim(iter->substr(last_pos + 1, string::npos));
     }else{
       // formatted by "accesskey:secretkey"
-      bucket    = allbucket_fields_type;
+      bucketname    = allbucket_fields_type;
       accesskey = trim(iter->substr(0, first_pos));
       secret    = trim(iter->substr(first_pos + 1, string::npos));
     }
-    if(resmap.end() != resmap.find(bucket)){
-      S3FS_PRN_EXIT("there are multiple entries for the same bucket(%s) in the passwd file.", ("" == bucket ? "default" : bucket.c_str()));
+    if(resmap.end() != resmap.find(bucketname)){
+      S3FS_PRN_EXIT("there are multiple entries for the same bucket(%s) in the passwd file.", ("" == bucketname ? "default" : bucketname.c_str()));
       return -1;
     }
     kv.clear();
     kv[string(aws_accesskeyid)] = accesskey;
     kv[string(aws_secretkey)]   = secret;
-    resmap[bucket]              = kv;
+    resmap[bucketname]          = kv;
   }
   return (resmap.empty() ? 0 : 1);
 }