diff --git a/src/basic/vx_config/config.tab.cc b/src/basic/vx_config/config.tab.cc
index 7c1d9c2c4c..692906aed4 100644
--- a/src/basic/vx_config/config.tab.cc
+++ b/src/basic/vx_config/config.tab.cc
@@ -134,7 +134,7 @@ extern "C" int        configwrap();
 
 char *            configtext;
 
-FILE *            configin;
+stringstream      configbuf;
 
 int               LineNumber            = 1;
 
diff --git a/src/basic/vx_config/config.tab.yy b/src/basic/vx_config/config.tab.yy
index 3544627fef..4ec680ee9d 100644
--- a/src/basic/vx_config/config.tab.yy
+++ b/src/basic/vx_config/config.tab.yy
@@ -59,7 +59,7 @@ extern "C" int        configwrap();
 
 char *            configtext;
 
-FILE *            configin;
+stringstream      configbuf;
 
 int               LineNumber            = 1;
 
diff --git a/src/basic/vx_config/config_file.cc b/src/basic/vx_config/config_file.cc
index 490a0d6d9b..77b66ef1aa 100644
--- a/src/basic/vx_config/config_file.cc
+++ b/src/basic/vx_config/config_file.cc
@@ -41,7 +41,7 @@ using namespace std;
 
 extern int configparse();
 
-extern FILE * configin;
+extern stringstream configbuf;
 
 extern int configdebug;
 
@@ -298,104 +298,105 @@ return n;
 ////////////////////////////////////////////////////////////////////////
 
 
-bool MetConfig::read(const char * name)
+bool MetConfig::read(const char * filename)
 
 {
 
-if ( empty(name) )  {
+set_buffer_from_file(filename);
 
-   mlog << Error << "\nMetConfig::read(const char *) -> "
-        << "empty filename!\n\n";
-
-   exit ( 1 );
+return parse_buffer();
 
 }
 
-DictionaryStack DS(*this);
-ConcatString temp_filename = get_tmp_dir();
- 
-temp_filename << "/" << "met_config";
-temp_filename = make_temp_file_name(temp_filename.c_str(), nullptr);
- 
-recursive_envs(name, temp_filename.c_str());
 
-bison_input_filename = temp_filename.c_str();
+////////////////////////////////////////////////////////////////////////
 
-dict_stack = &DS;
 
-LineNumber = 1;
+bool MetConfig::read_string(const char * config_string)
 
-Column     = 1;
+{
 
-is_lhs     = true;
+set_buffer_from_string(config_string);
 
-Filename.add(bison_input_filename);
+return parse_buffer();
 
-configdebug = (Debug ? 1 : 0);
+}
 
-if ( (configin = met_fopen(bison_input_filename, "r")) == nullptr )  {
 
-   mlog << Error << "\nMetConfig::read(const char *) -> "
-        << "unable to open input file \"" << bison_input_filename << "\"\n\n";
+////////////////////////////////////////////////////////////////////////
+
+
+void MetConfig::set_buffer_from_file(const char * filename)
+
+{
+
+if ( empty(filename) )  {
+
+   mlog << Error << "\nMetConfig::set_buffer_from_file(const char *) -> "
+        << "empty filename!\n\n";
 
    exit ( 1 );
 
 }
 
-int parse_status;
+   // Open input config file
 
-parse_status = configparse();
+ifstream configfilein;
 
-if ( configin )  {
+met_open(configfilein, filename);
 
-   fclose(configin);
-   configin = (FILE *) nullptr;
+if ( ! configfilein )  {
+
+   mlog << Error << "\nMetConfig::read(const char *) -> "
+        << "unable to open input file \"" << filename << "\"\n\n";
+
+   exit ( 1 );
 
 }
 
-if ( parse_status != 0 )  {
+   // Read contents into buffer
 
-   return false;
+string line;
 
-}
+while ( getline(configfilein, line) )  {
 
-if ( DS.n_elements() != 1 )  {
+   recursive_envs(line);
 
-   mlog << Error << "\nMetConfig::read(const char *) -> "
-        << "should be only one dictionary left after parsing! ...("
-        << DS.n_elements() << ")\n\n";
+   configbuf << line << "\n";
 
-   DS.dump(cout);
-   DS.dump_config_format(cout);
+}
 
-   mlog << Error << "\n"
-        << "parse failed!\n\n";
+   // Close the input file
+ 
+configfilein.close();
 
-   exit ( 1 );
+bison_input_filename = filename;
+
+Filename.add(filename);
+
+return;
 
 }
 
-   //
-   //  done
-   //
 
-patch_parents();
+////////////////////////////////////////////////////////////////////////
 
-bison_input_filename = (const char *) nullptr;
 
-dict_stack = (DictionaryStack *) nullptr;
+void MetConfig::set_buffer_from_string(const char * config_string)
 
-LineNumber = 1;
+{
 
-Column     = 1;
+string line(config_string);
 
-is_lhs     = true;
+recursive_envs(line);
 
-set_exit_on_warning();
+configbuf << line << "\n";
 
-unlink(temp_filename.c_str());
+bison_input_filename = "config_string";
 
-return true;
+Filename.add("config_string");
+
+return;
 
 }
 
@@ -403,51 +404,65 @@ return true;
 ////////////////////////////////////////////////////////////////////////
 
 
-bool MetConfig::read_string(const char * s)
+bool MetConfig::parse_buffer()
 
 {
 
-if ( empty(s) )  {
+DictionaryStack DS(*this);
 
-   mlog << Error << "\nMetConfig::read_string(const char *) -> "
-        << "empty input string!\n\n";
+dict_stack = &DS;
 
-   exit ( 1 );
+LineNumber = 1;
 
-}
+Column     = 1;
 
-   //
-   //  write temporary config file
-   //  default to the current directory
-   //
+is_lhs     = true;
 
-ofstream out;
-ConcatString temp_filename = get_tmp_dir();
+configdebug = (Debug ? 1 : 0);
 
-temp_filename << "/" << "met_config";
-temp_filename = make_temp_file_name(temp_filename.c_str(), nullptr);
- 
-out.open(temp_filename.c_str());
+int parse_status = configparse();
 
-if ( ! out )  {
+if ( parse_status != 0 )  {
+
+   return false;
 
-   mlog << Error << "\nMetConfig::read_string(const char *) -> "
-        << "unable to open temp file \"" << temp_filename << "\".\n"
-        << "Set MET_TMP_DIR to specify a temporary directory.\n\n";
+}
+
+if ( DS.n_elements() != 1 )  {
+
+   mlog << Error << "\nMetConfig::parse_buffer(const char *) -> "
+        << "should be only one dictionary left after parsing! ...("
+        << DS.n_elements() << ")\n\n";
+
+   DS.dump(cout);
+   DS.dump_config_format(cout);
+
+   mlog << Error << "\n"
+        << "parse failed!\n\n";
 
    exit ( 1 );
 
 }
 
-out << s << '\n';
+   //
+   //  done
+   //
+
+patch_parents();
 
-out.close();
+bison_input_filename = (const char *) nullptr;
 
-bool status = read(temp_filename.c_str());
+dict_stack = (DictionaryStack *) nullptr;
 
-remove_temp_file(temp_filename);
+LineNumber = 1;
 
-return status;
+Column     = 1;
+
+is_lhs     = true;
+
+set_exit_on_warning();
+
+return true;
 
 }
 
diff --git a/src/basic/vx_config/config_file.h b/src/basic/vx_config/config_file.h
index 7989e98c3a..1ab52b2812 100644
--- a/src/basic/vx_config/config_file.h
+++ b/src/basic/vx_config/config_file.h
@@ -34,6 +34,12 @@ class MetConfig : public Dictionary {
 
       void assign(const MetConfig &);
 
+      void set_buffer_from_file(const char *);
+
+      void set_buffer_from_string(const char *);
+
+      bool parse_buffer();
+
       StringArray Filename;
 
       bool Debug;
@@ -78,7 +84,7 @@ class MetConfig : public Dictionary {
 
       bool read(const char * filename);
 
-      bool read_string(const char *);
+      bool read_string(const char * config_string);
 
       const DictionaryEntry * lookup(const char * name);
 
diff --git a/src/basic/vx_config/my_config_scanner.cc b/src/basic/vx_config/my_config_scanner.cc
index 023c4da57a..06b56348c7 100644
--- a/src/basic/vx_config/my_config_scanner.cc
+++ b/src/basic/vx_config/my_config_scanner.cc
@@ -52,7 +52,7 @@ extern int LineNumber;
 
 extern int Column;
 
-extern FILE * configin;
+extern stringstream configbuf;
 
 extern char * configtext;
 
@@ -732,7 +732,7 @@ n = 0;
 
 while ( n < max_id_length )  {
 
-   c = fgetc(configin);
+   c = configbuf.get();
 
    if ( c == EOF )  break;
 
@@ -740,7 +740,7 @@ while ( n < max_id_length )  {
 
    if ( c == '\\' )  {
 
-     c = fgetc(configin);
+     c = configbuf.get();
 
      if ( c == EOF )  break;
 
@@ -848,7 +848,7 @@ while ( 1 )  {
 
    c1 = c2;
 
-   c2 = fgetc(configin);
+   c2 = configbuf.get();
 
 }
 
@@ -873,9 +873,9 @@ reading_comment = true;
 
 while ( 1 )  {
 
-   if ( feof (configin) )  break;
+   if ( configbuf.eof() )  break;
 
-   c = fgetc(configin);
+   c = configbuf.get();
 
    if ( (c == eof) || (c == '\n') )  break;
 
@@ -999,15 +999,15 @@ if ( reading_env )   {
    //  not reading env
    //
 
-if ( feof(configin) )  return eof;
+if ( configbuf.eof() )  return eof;
 
-c = fgetc(configin);
+c = configbuf.get();
 
 if ( c == '\n' )   { ++LineNumber;  Column = 0; }
 
 if ( c == '$' )  {
 
-   cc = fgetc(configin);
+   cc = configbuf.get();
 
    ++Column;
 
@@ -1029,7 +1029,7 @@ if ( c == '$' )  {
 
    // SonarQube: to avoid side effect by || operator
    while (env_pos < max_id_length) {
-      if ((c = fgetc(configin)) == R_curly) break;
+      if ((c = configbuf.get()) == R_curly) break;
       env_name[env_pos++] = (char) c;
    }