--- a/doc/build-waf.txt	Wed May 23 17:32:32 2007 +0100
+++ b/doc/build-waf.txt	Wed May 23 19:20:54 2007 +0100
@@ -35,6 +35,17 @@
     Run code coverage analysis (assuming the project was configured
 with --enable-gcov)
 
+ 4. ./waf --run "program [args]"
+    Run a ns3 program, given its target name, with the given
+    arguments.  This takes care of automatically modifying the the
+    path for finding the ns3 dynamic libraries in the environment
+    before running the program.  Note: the "program [args]" string is
+    parsed using POSIX shell rules.
+
+ 5. ./waf --shell
+    Starts a nested system shell with modified environment to run ns3 programs.
+
+
 === Extending ns-3 ===
 
 To add new modules:

--- a/src/wscript	Wed May 23 17:32:32 2007 +0100
+++ b/src/wscript	Wed May 23 19:20:54 2007 +0100
@@ -17,35 +17,17 @@
 
 def set_options(opt):
     opt.sub_options('simulator')
-
-    rpath_default = (sys.platform == 'linux2')
-    opt.add_option('--enable-rpath',
-                   help=("Link programs with rpath"),
-                   action="store_true", dest='enable_rpath', default=rpath_default)
-    opt.add_option('--disable-rpath',
-                   help=("Don't link programs with rpath"),
-                   action="store_false", dest='enable_rpath', default=rpath_default)
     
 def configure(conf):
     conf.sub_config('core')
     conf.sub_config('simulator')
 
-    conf.env['ENABLE_RPATH'] = Params.g_options.enable_rpath
-
 
 def build(bld):
-
-    ## Add a global RPATH pointing to each module, so that programs can find the libs
-    ## Note: this is slightly evil; we get away because our programs
-    ## and libs are not supposed to be installed system wide.
     env = bld.env_of_name('default')
     for module in all_modules:
         node = bld.m_curdirnode.find_dir(module)
-        if sys.platform == 'win32':
-            os.environ["PATH"] = ';'.join([os.environ["PATH"], node.abspath(env)])
-        else:
-            if env['ENABLE_RPATH']:
-                env.append_value('RPATH', '-Wl,-rpath=%s' % (node.abspath(env),))
+        node_path = node.abspath(env)
+        env.append_value('NS3_MODULE_PATH', node_path)
     
     bld.add_subdirs(all_modules)
-

--- a/wscript	Wed May 23 17:32:32 2007 +0100
+++ b/wscript	Wed May 23 19:20:54 2007 +0100
@@ -1,6 +1,7 @@
 ## -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 import os
 import sys
+import shlex
 
 import Params
 import Object
@@ -90,6 +91,15 @@
                    action="store_true", default=False,
                    dest='doxygen')
 
+    opt.add_option('--run',
+                   help=('Run a locally built program'),
+                   type="string", default='', dest='run')
+
+    opt.add_option('--shell',
+                   help=('Run a shell with an environment suitably modified to run locally built programs'),
+                   action="store_true", default=False,
+                   dest='shell')
+
     # options provided in a script in a subdirectory named "src"
     opt.sub_options('src')
 
@@ -138,20 +148,90 @@
 
 
 def shutdown():
-    import UnitTest
-    ut = UnitTest.unit_test()
-    ut.change_to_testfile_dir = True
-    ut.want_to_see_test_output = True
-    ut.want_to_see_test_error = True
-    ut.run()
+    #import UnitTest
+    #ut = UnitTest.unit_test()
+    #ut.change_to_testfile_dir = True
+    #ut.want_to_see_test_output = True
+    #ut.want_to_see_test_error = True
+    #ut.run()
     #ut.print_results()
 
+    if Params.g_commands['check']:
+        run_program('run-tests')
+
     if Params.g_options.lcov_report:
         lcov_report()
 
     if Params.g_options.doxygen:
         doxygen()
 
+    if Params.g_options.run:
+        run_program(Params.g_options.run)
+
+    elif Params.g_options.shell:
+        run_shell()
+
+def _find_program(program_name):
+    for obj in Object.g_allobjs:
+        if obj.target == program_name:
+            return obj
+    raise ValueError("progam '%s' not found" % (program_name,))
+
+def _run_argv(argv):
+    env = Params.g_build.env_of_name('default')
+    if sys.platform == 'linux2':
+        pathvar = 'LD_LIBRARY_PATH'
+        pathsep = ':'
+    elif sys.platform == 'darwin':
+        pathvar = 'DYLD_LIBRARY_PATH'
+        pathsep = ':'
+    elif sys.platform == 'win32':
+        pathvar = 'PATH'
+        pathsep = ';'
+    else:
+        Params.warning(("Don't know how to configure "
+                        "dynamic library path for the platform '%s'") % (sys.platform,))
+        pathvar = None
+        pathsep = None
+
+    os_env = dict(os.environ)
+    if pathvar is not None:
+        if pathvar in os_env:
+            os_env[pathvar] = pathsep.join([os_env[pathvar]] + list(env['NS3_MODULE_PATH']))
+        else:
+            os_env[pathvar] = pathsep.join(list(env['NS3_MODULE_PATH']))
+
+    retval = subprocess.Popen(argv, env=os_env).wait()
+    if retval:
+        raise SystemExit(retval)
+
+
+def run_program(program_string):
+    env = Params.g_build.env_of_name('default')
+    argv = shlex.split(program_string)
+    program_name = argv[0]
+
+    try:
+        program_obj = _find_program(program_name)
+    except ValueError:
+        Params.fatal("progam '%s' not found" % (program_name,))
+
+    try:
+        program_node, = program_obj.m_linktask.m_outputs
+    except AttributeError:
+        Params.fatal("%s does not appear to be a program" % (program_name,))
+
+    execvec = [program_node.abspath(env)] + argv[1:]
+    return _run_argv(execvec)
+
+
+def run_shell():
+    if sys.platform == 'win32':
+        shell = os.environ.get("COMSPEC", "cmd.exe")
+    else:
+        shell = os.environ.get("SHELL", "/bin/sh")
+    _run_argv([shell])
+
 
 def doxygen():
     doxygen_config = os.path.join('doc', 'doxygen.conf')