diff --git a/util/qbdriver/testlock.C b/util/qbdriver/testlock.C
new file mode 100644
index 0000000..921d1cc
--- /dev/null
+++ b/util/qbdriver/testlock.C
@@ -0,0 +1,41 @@
+//
+// testlock.C
+//
+// test the creation and removal of a lock file using the C library
+//
+
+#include <stdio.h>    // fopen, fclose, fprintf
+#include <sys/stat.h> // stat()
+#include <unistd.h>   // fsync()
+int main()
+{
+  // create a lock file "lock.dat"
+  FILE *lockfile = fopen("lock.dat","w");
+  fprintf(lockfile,"1");
+  fclose(lockfile);
+  fsync(fileno(lockfile));
+
+  // test for the presence of the lock file
+  struct stat statbuf;
+  int status;
+  do
+  {
+    // stat returns 0 if the file exists
+    status = stat("lock.dat",&statbuf);
+    usleep(100000);
+  }
+  while ( status != 0 );
+
+  // remove the lock file
+  remove("lock.dat");
+  usleep(100000);
+
+  // test for the absence of the file
+  do
+  {
+    // stat returns 0 if the file exists
+    status = stat("lock.dat",&statbuf);
+    usleep(100000);
+  }
+  while ( status == 0 );
+}
diff --git a/util/qbdriver/testreassign.C b/util/qbdriver/testreassign.C
new file mode 100644
index 0000000..d2d1b14
--- /dev/null
+++ b/util/qbdriver/testreassign.C
@@ -0,0 +1,50 @@
+//
+// testreassign.C
+//
+// test the functionality of:
+// - reassign the streambuf of std::cout to an ostringstream
+// - write and sync using C library functions
+//
+// This program tests the functionality needed in UserInterface when 
+// operating in server mode. In that case, the std::cout stream is redirected
+// to an ostringstream. The contents of the ostringstream are written at the
+// end using C library functions, which allow for the use of the fsync() call.
+//
+
+#include <unistd.h>
+#include <iostream>
+#include <fstream>
+#include <sstream>
+int main()
+{
+  // write something to std::cout before reassign
+  std::cout << "initial write on std::cout" << std::endl;
+
+  // streambuf pointers
+  std::streambuf *qbout_buf;
+  std::streambuf *cout_buf;
+
+  // save copy of cout streambuf
+  cout_buf = std::cout.rdbuf();
+  // create an ostringstream
+  std::ostringstream os;
+  qbout_buf = os.rdbuf();
+  // redirect std::cout to os
+  std::cout.rdbuf(qbout_buf);
+
+  // the following output should go to the ostringstream
+  std::cout << " output written to cout after redirect" << std::endl;
+  std::cout.flush();
+
+  // write contents of os to file "out.txt"
+  FILE *qboutfile = fopen("out.txt","w");
+  fprintf(qboutfile,"%s",os.str().c_str());
+  fclose(qboutfile);
+  fsync(fileno(qboutfile));
+
+  // restore cout streambuf
+  std::cout.rdbuf(cout_buf);
+
+  // write more output to std::cout
+  std::cout << "more output on std::cout" << std::endl;
+}