.. include:: replace.txt .. highlight:: bash Getting Started --------------- This section is aimed at getting a user to a working state starting with a machine that may never have had |ns3| installed. It covers supported platforms, prerequisites, ways to obtain |ns3|, ways to build |ns3|, and ways to verify your build and run simple programs. Overview ******** |ns3| is built as a system of software libraries that work together. User programs can be written that links with (or imports from) these libraries. User programs are written in either the C++ or Python programming languages. |ns3| is distributed as source code, meaning that the target system needs to have a software development environment to build the libraries first, then build the user program. |ns3| could in principle be distributed as pre-built libraries for selected systems, and in the future it may be distributed that way, but at present, many users actually do their work by editing |ns3| itself, so having the source code around to rebuild the libraries is useful. If someone would like to undertake the job of making pre-built libraries and packages for operating systems, please contact the ns-developers mailing list. In the following, we'll look at two ways of downloading and building |ns3|. The first is to download and build an official release from the main web site. The second is to fetch and build development copies of |ns3|. We'll walk through both examples since the tools involved are slightly different. Downloading |ns3| ***************** The |ns3| system as a whole is a fairly complex system and has a number of dependencies on other components. Along with the systems you will most likely deal with every day (the GNU toolchain, Mercurial, a text editor) you will need to ensure that a number of additional libraries are present on your system before proceeding. |ns3| provides a wiki page that includes pages with many useful hints and tips. One such page is the "Installation" page, http://www.nsnam.org/wiki/Installation. The "Prerequisites" section of this wiki page explains which packages are required to support common |ns3| options, and also provides the commands used to install them for common Linux variants. Cygwin users will have to use the Cygwin installer (if you are a Cygwin user, you used it to install Cygwin). You may want to take this opportunity to explore the |ns3| wiki a bit since there really is a wealth of information there. From this point forward, we are going to assume that the reader is working in Linux or a Linux emulation environment (Linux, Cygwin, etc.) and has the GNU toolchain installed and verified along with the prerequisites mentioned above. We are also going to assume that you have Mercurial and Waf installed and running on the target system. The |ns3| code is available in Mercurial repositories on the server http://code.nsnam.org. You can also download a tarball release at http://www.nsnam.org/release/, or you can work with repositories using Mercurial. We recommend using Mercurial unless there's a good reason not to. See the end of this section for instructions on how to get a tarball release. The simplest way to get started using Mercurial repositories is to use the ``ns-3-allinone`` environment. This is a set of scripts that manages the downloading and building of various subsystems of |ns3| for you. We recommend that you begin your |ns3| work in this environment. One practice is to create a directory called ``workspace`` in one's home directory under which one can keep local Mercurial repositories. Any directory name will do, but we'll assume that ``workspace`` is used herein (note: ``repos`` may also be used in some documentation as an example directory name). Downloading |ns3| Using a Tarball +++++++++++++++++++++++++++++++++ A tarball is a particular format of software archive where multiple files are bundled together and the archive possibly compressed. |ns3| software releases are provided via a downloadable tarball. The process for downloading |ns3| via tarball is simple; you just have to pick a release, download it and decompress it. Let's assume that you, as a user, wish to build |ns3| in a local directory called ``workspace``. If you adopt the ``workspace`` directory approach, you can get a copy of a release by typing the following into your Linux shell (substitute the appropriate version numbers, of course):: $ cd $ mkdir workspace $ cd workspace $ wget http://www.nsnam.org/release/ns-allinone-3.27.tar.bz2 $ tar xjf ns-allinone-3.27.tar.bz2 If you change into the directory ``ns-allinone-3.27`` you should see a number of files and directories: :: $ ls bake constants.py ns-3.27 README build.py netanim-3.108 pybindgen-0.17.0.post58+ngcf00cc0 util.py You are now ready to build the base |ns3| distribution and may skip ahead to the section on building |ns3|. Downloading |ns3| Using Bake ++++++++++++++++++++++++++++ Bake is a tool for distributed integration and building, developed for the |ns3| project.  Bake can be used to fetch development versions of the |ns3| software, and to download and build extensions to the base |ns3| distribution, such as the Direct Code Execution environment, Network Simulation Cradle, ability to create new Python bindings, and others. In recent |ns3| releases, Bake has been included in the release tarball. The configuration file included in the released version will allow one to download any software that was current at the time of the release. That is, for example, the version of Bake that is distributed with the ``ns-3.21`` release can be used to fetch components for that |ns3| release or earlier, but can't be used to fetch components for later releases (unless the ``bakeconf.xml`` file is updated). You can also get the most recent copy of ``bake`` by typing the following into your Linux shell (assuming you have installed Mercurial):: $ cd $ mkdir workspace $ cd workspace $ hg clone http://code.nsnam.org/bake As the hg (Mercurial) command executes, you should see something like the following displayed, :: ... destination directory: bake requesting all changes adding changesets adding manifests adding file changes added 339 changesets with 796 changes to 63 files updating to branch default 45 files updated, 0 files merged, 0 files removed, 0 files unresolved After the clone command completes, you should have a directory called ``bake``, the contents of which should look something like the following:: $ ls bake bakeconf.xml doc generate-binary.py TODO bake.py examples test Notice that you really just downloaded some Python scripts and a Python module called ``bake``. The next step will be to use those scripts to download and build the |ns3| distribution of your choice. There are a few configuration targets available: 1. ``ns-3.27``: the module corresponding to the release; it will download components similar to the release tarball. 2. ``ns-3-dev``: a similar module but using the development code tree 3. ``ns-allinone-3.27``: the module that includes other optional features such as click routing, openflow for |ns3|, and the Network Simulation Cradle 4. ``ns-3-allinone``: similar to the released version of the allinone module, but for development code. The current development snapshot (unreleased) of |ns3| may be found at http://code.nsnam.org/ns-3-dev/. The developers attempt to keep these repository in consistent, working states but they are in a development area with unreleased code present, so you may want to consider staying with an official release if you do not need newly- introduced features. You can find the latest version of the code either by inspection of the repository list or by going to the `"ns-3 Releases" `_ web page and clicking on the latest release link. We'll proceed in this tutorial example with ``ns-3.27``. We are now going to use the bake tool to pull down the various pieces of |ns3| you will be using. First, we'll say a word about running bake. bake works by downloading source packages into a source directory, and installing libraries into a build directory. bake can be run by referencing the binary, but if one chooses to run bake from outside of the directory it was downloaded into, it is advisable to put bake into your path, such as follows (Linux bash shell example). First, change into the 'bake' directory, and then set the following environment variables :: $ export BAKE_HOME=`pwd` $ export PATH=$PATH:$BAKE_HOME:$BAKE_HOME/build/bin $ export PYTHONPATH=$PYTHONPATH:$BAKE_HOME:$BAKE_HOME/build/lib This will put the bake.py program into the shell's path, and will allow other programs to find executables and libraries created by bake. Although several bake use cases do not require setting PATH and PYTHONPATH as above, full builds of ns-3-allinone (with the optional packages) typically do. Step into the workspace directory and type the following into your shell:: $ ./bake.py configure -e ns-3.27 Next, we'll ask bake to check whether we have enough tools to download various components. Type:: $ ./bake.py check You should see something like the following, :: > Python - OK > GNU C++ compiler - OK > Mercurial - OK > CVS - OK > GIT - OK > Bazaar - OK > Tar tool - OK > Unzip tool - OK > Unrar tool - is missing > 7z data compression utility - OK > XZ data compression utility - OK > Make - OK > cMake - OK > patch tool - OK > autoreconf tool - OK > Path searched for tools: /usr/lib64/qt-3.3/bin /usr/lib64/ccache /usr/local/bin /bin /usr/bin /usr/local/sbin /usr/sbin /sbin bin In particular, download tools such as Mercurial, CVS, GIT, and Bazaar are our principal concerns at this point, since they allow us to fetch the code. Please install missing tools at this stage, in the usual way for your system (if you are able to), or contact your system administrator as needed to install these tools. Next, try to download the software:: $ ./bake.py download should yield something like:: >> Searching for system dependency setuptools - OK >> Searching for system dependency pygoocanvas - OK >> Searching for system dependency pygraphviz - OK >> Searching for system dependency python-dev - OK >> Searching for system dependency libxml2-dev - OK >> Searching for system dependency clang-dev - OK >> Downloading click-ns-3.25 - OK >> Downloading BRITE - OK >> Searching for system dependency qt4 - OK >> Downloading nsc-0.5.3 - OK >> Searching for system dependency g++ - OK >> Downloading castxml - OK >> Downloading openflow-ns-3.25 - OK >> Downloading netanim-3.108 - OK >> Downloading pygccxml-1.9.1 - OK >> Downloading pygccxml - OK >> Downloading pybindgen-ns3.27-castxml (target directory:pybindgen) - OK >> Downloading ns-3.27 - OK The above suggests that seven sources have been downloaded. Check the ``source`` directory now and type ``ls``; one should see:: $ ls BRITE netanim-3.108 openflow-ns-3.25 pygccxml-1.9.1 castxml ns-3.27 pybindgen v1.9.1.tar.gz click-ns-3.25 nsc-0.5.3 pygccxml You are now ready to build the |ns3| distribution. Building |ns3| ************** Building with ``build.py`` ++++++++++++++++++++++++++ When working from a released tarball, the first time you build the |ns3| project you can build using a convenience program found in the ``allinone`` directory. This program is called ``build.py``. This program will get the project configured for you in the most commonly useful way. However, please note that more advanced configuration and work with |ns3| will typically involve using the native |ns3| build system, Waf, to be introduced later in this tutorial. If you downloaded using a tarball you should have a directory called something like ``ns-allinone-3.27`` under your ``~/workspace`` directory. Type the following:: $ ./build.py --enable-examples --enable-tests Because we are working with examples and tests in this tutorial, and because they are not built by default in |ns3|, the arguments for build.py tells it to build them for us. The program also defaults to building all available modules. Later, you can build |ns3| without examples and tests, or eliminate the modules that are not necessary for your work, if you wish. You will see lots of typical compiler output messages displayed as the build script builds the various pieces you downloaded. Eventually you should see the following:: Waf: Leaving directory `/path/to/workspace/ns-allinone-3.27/ns-3.27/build' 'build' finished successfully (6m25.032s) Modules built: antenna aodv applications bridge buildings config-store core csma csma-layout dsdv dsr energy fd-net-device flow-monitor internet internet-apps lr-wpan lte mesh mobility mpi netanim (no Python) network nix-vector-routing olsr openflow (no Python) point-to-point point-to-point-layout propagation sixlowpan spectrum stats tap-bridge test (no Python) topology-read traffic-control uan virtual-net-device visualizer wave wifi wimax Modules not built (see ns-3 tutorial for explanation): brite click Regarding the portion about modules not built:: Modules not built (see ns-3 tutorial for explanation): brite click This just means that some |ns3| modules that have dependencies on outside libraries may not have been built, or that the configuration specifically asked not to build them. It does not mean that the simulator did not build successfully or that it will provide wrong results for the modules listed as being built. Building with bake ++++++++++++++++++ If you used bake above to fetch source code from project repositories, you may continue to use it to build |ns3|. Type :: $ ./bake.py build and you should see something like:: >> Building BRITE - OK >> Building nsc-0.5.3 - OK >> Building click-ns-3.25 - OK ... >> Building ns-3.27 - OK *Hint: you can also perform both steps, download and build, by calling ``bake.py deploy``.* There may be failures to build all components, but the build will proceed anyway if the component is optional. For example, a common issue at the moment is that castxml may not build via the bake build tool on all platforms; in this case, the line will show:: >> Building castxml - Problem > Problem: Optional dependency, module "castxml" failed This may reduce the functionality of the final build. However, bake will continue since "castxml" is not an essential dependency. For more information call bake with -v or -vvv, for full verbose mode. However, castxml is only needed if one wants to generate updated Python bindings, and most users do not need to do so (or to do so until they are more involved with ns-3 changes), so such warnings might be safely ignored for now. If there happens to be a failure, please have a look at what the following command tells you; it may give a hint as to a missing dependency:: $ ./bake.py show This will list out the various dependencies of the packages you are trying to build. Building with Waf +++++++++++++++++ Up to this point, we have used either the `build.py` script, or the `bake` tool, to get started with building |ns3|. These tools are useful for building |ns3| and supporting libraries, and they call into the |ns3| directory to call the Waf build tool to do the actual building. Most users quickly transition to using Waf directly to configure and build |ns3|. So, to proceed, please change your working directory to the |ns3| directory that you have initially built. It's not strictly required at this point, but it will be valuable to take a slight detour and look at how to make changes to the configuration of the project. Probably the most useful configuration change you can make will be to build the optimized version of the code. By default you have configured your project to build the debug version. Let's tell the project to make an optimized build. To explain to Waf that it should do optimized builds that include the examples and tests, you will need to execute the following commands:: $ ./waf clean $ ./waf configure --build-profile=optimized --enable-examples --enable-tests This runs Waf out of the local directory (which is provided as a convenience for you). The first command to clean out the previous build is not typically strictly necessary but is good practice (but see `Build Profiles`_, below); it will remove the previously built libraries and object files found in directory ``build/``. When the project is reconfigured and the build system checks for various dependencies, you should see output that looks similar to the following:: Setting top to : . Setting out to : build Checking for 'gcc' (c compiler) : /usr/bin/gcc Checking for cc version : 4.2.1 Checking for 'g++' (c++ compiler) : /usr/bin/g++ Checking boost includes : 1_46_1 Checking boost libs : ok Checking for boost linkage : ok Checking for click location : not found Checking for program pkg-config : /sw/bin/pkg-config Checking for 'gtk+-2.0' >= 2.12 : yes Checking for 'libxml-2.0' >= 2.7 : yes Checking for type uint128_t : not found Checking for type __uint128_t : yes Checking high precision implementation : 128-bit integer (default) Checking for header stdint.h : yes Checking for header inttypes.h : yes Checking for header sys/inttypes.h : not found Checking for header sys/types.h : yes Checking for header sys/stat.h : yes Checking for header dirent.h : yes Checking for header stdlib.h : yes Checking for header signal.h : yes Checking for header pthread.h : yes Checking for header stdint.h : yes Checking for header inttypes.h : yes Checking for header sys/inttypes.h : not found Checking for library rt : not found Checking for header netpacket/packet.h : not found Checking for header sys/ioctl.h : yes Checking for header net/if.h : not found Checking for header net/ethernet.h : yes Checking for header linux/if_tun.h : not found Checking for header netpacket/packet.h : not found Checking for NSC location : not found Checking for 'mpic++' : yes Checking for 'sqlite3' : yes Checking for header linux/if_tun.h : not found Checking for program sudo : /usr/bin/sudo Checking for program valgrind : /sw/bin/valgrind Checking for 'gsl' : yes Checking for compilation flag -Wno-error=deprecated-d... support : ok Checking for compilation flag -Wno-error=deprecated-d... support : ok Checking for compilation flag -fstrict-aliasing... support : ok Checking for compilation flag -fstrict-aliasing... support : ok Checking for compilation flag -Wstrict-aliasing... support : ok Checking for compilation flag -Wstrict-aliasing... support : ok Checking for program doxygen : /usr/local/bin/doxygen ---- Summary of optional NS-3 features: Build profile : debug BRITE Integration : not enabled (BRITE not enabled (see option --with-brite)) Build directory : build Build examples : enabled Build tests : enabled Emulated Net Device : enabled ( include not detected) Emulation FdNetDevice : not enabled (needs netpacket/packet.h) File descriptor NetDevice : enabled GNU Scientific Library (GSL) : enabled GtkConfigStore : enabled MPI Support : enabled NS-3 Click Integration : not enabled (nsclick not enabled (see option --with-nsclick)) NS-3 OpenFlow Integration : not enabled (Required boost libraries not found, missing: system, signals, filesystem) Network Simulation Cradle : not enabled (NSC not found (see option --with-nsc)) PlanetLab FdNetDevice : not enabled (PlanetLab operating system not detected (see option --force-planetlab)) PyViz visualizer : enabled Python Bindings : enabled Real Time Simulator : enabled (librt is not available) SQlite stats data output : enabled Tap Bridge : not enabled ( include not detected) Tap FdNetDevice : not enabled (needs linux/if_tun.h) Threading Primitives : enabled Use sudo to set suid bit : not enabled (option --enable-sudo not selected) XmlIo : enabled 'configure' finished successfully (1.944s) Note the last part of the above output. Some |ns3| options are not enabled by default or require support from the underlying system to work properly. For instance, to enable XmlTo, the library libxml-2.0 must be found on the system. If this library were not found, the corresponding |ns3| feature would not be enabled and a message would be displayed. Note further that there is a feature to use the program ``sudo`` to set the suid bit of certain programs. This is not enabled by default and so this feature is reported as "not enabled." Finally, to reprint this summary of which optional features are enabled, use the ``--check-config`` option to waf. Now go ahead and switch back to the debug build that includes the examples and tests. :: $ ./waf clean $ ./waf configure --build-profile=debug --enable-examples --enable-tests The build system is now configured and you can build the debug versions of the |ns3| programs by simply typing :: $ ./waf Okay, sorry, I made you build the |ns3| part of the system twice, but now you know how to change the configuration and build optimized code. A command exists for checking which profile is currently active for an already configured project:: $ ./waf --check-profile Waf: Entering directory \`/path/to/ns-3-allinone/ns-3.27/build' Build profile: debug The build.py script discussed above supports also the ``--enable-examples`` and ``enable-tests`` arguments, but in general, does not directly support other waf options; for example, this will not work: :: $ ./build.py --disable-python will result in :: build.py: error: no such option: --disable-python However, the special operator ``--`` can be used to pass additional options through to waf, so instead of the above, the following will work: :: $ ./build.py -- --disable-python as it generates the underlying command ``./waf configure --disable-python``. Here are a few more introductory tips about Waf. Configure vs. Build =================== Some Waf commands are only meaningful during the configure phase and some commands are valid in the build phase. For example, if you wanted to use the emulation features of |ns3|, you might want to enable setting the suid bit using sudo as described above. This turns out to be a configuration-time command, and so you could reconfigure using the following command that also includes the examples and tests. :: $ ./waf configure --enable-sudo --enable-examples --enable-tests If you do this, Waf will have run sudo to change the socket creator programs of the emulation code to run as root. There are many other configure- and build-time options available in Waf. To explore these options, type:: $ ./waf --help We'll use some of the testing-related commands in the next section. Build Profiles ============== We already saw how you can configure Waf for ``debug`` or ``optimized`` builds:: $ ./waf --build-profile=debug There is also an intermediate build profile, ``release``. ``-d`` is a synonym for ``--build-profile``. The build profile controls the use of logging, assertions, and compiler optimization: +--------------------+---------------------------------+-----------------------------------------------------------------+ | Feature | Build Profile | + +---------------------------------+-------------------------------+---------------------------------+ | | ``debug`` | ``release`` | ``optimized`` | +====================+=================================+===============================+=================================+ | Enabled Features | | ``NS3_BUILD_PROFILE_DEBUG`` | ``NS3_BUILD_PROFILE_RELEASE`` | ``NS3_BUILD_PROFILE_OPTIMIZED`` | | | | ``NS_LOG...`` | | | | | | ``NS_ASSERT...`` | | | +--------------------+---------------------------------+-------------------------------+---------------------------------+ | Code Wrapper Macro | ``NS_BUILD_DEBUG(code)`` | ``NS_BUILD_RELEASE(code)`` | ``NS_BUILD_OPTIMIZED(code)`` | +--------------------+---------------------------------+-------------------------------+---------------------------------+ | Compiler Flags | ``-O0 -ggdb -g3`` | ``-O3 -g0`` | ``-O3 -g`` | | | | ``-fomit-frame-pointer`` | ``-fstrict-overflow`` | | | | | ``-march=native`` | +--------------------+---------------------------------+-------------------------------+---------------------------------+ As you can see, logging and assertions are only available in debug builds. Recommended practice is to develop your scenario in debug mode, then conduct repetitive runs (for statistics or changing parameters) in optimized build profile. If you have code that should only run in specific build profiles, use the indicated Code Wrapper macro: .. sourcecode:: cpp NS_BUILD_DEBUG (std::cout << "Part of an output line..." << std::flush; timer.Start ()); DoLongInvolvedComputation (); NS_BUILD_DEBUG (timer.Stop (); std::cout << "Done: " << timer << std::endl;) By default Waf puts the build artifacts in the ``build`` directory. You can specify a different output directory with the ``--out`` option, e.g. :: $ ./waf configure --out=foo Combining this with build profiles lets you switch between the different compile options in a clean way:: $ ./waf configure --build-profile=debug --out=build/debug $ ./waf build ... $ ./waf configure --build-profile=optimized --out=build/optimized $ ./waf build ... This allows you to work with multiple builds rather than always overwriting the last build. When you switch, Waf will only compile what it has to, instead of recompiling everything. When you do switch build profiles like this, you have to be careful to give the same configuration parameters each time. It may be convenient to define some environment variables to help you avoid mistakes:: $ export NS3CONFIG="--enable-examples --enable-tests" $ export NS3DEBUG="--build-profile=debug --out=build/debug" $ export NS3OPT=="--build-profile=optimized --out=build/optimized" $ ./waf configure $NS3CONFIG $NS3DEBUG $ ./waf build ... $ ./waf configure $NS3CONFIG $NS3OPT $ ./waf build Compilers and Flags =================== In the examples above, Waf uses the GCC C++ compiler, ``g++``, for building |ns3|. However, it's possible to change the C++ compiler used by Waf by defining the ``CXX`` environment variable. For example, to use the Clang C++ compiler, ``clang++``, :: $ CXX="clang++" ./waf configure $ ./waf build One can also set up Waf to do distributed compilation with ``distcc`` in a similar way:: $ CXX="distcc g++" ./waf configure $ ./waf build More info on ``distcc`` and distributed compilation can be found on it's `project page `_ under Documentation section. To add compiler flags, use the ``CXXFLAGS_EXTRA`` environment variable when you configure |ns3|. Install ======= Waf may be used to install libraries in various places on the system. The default location where libraries and executables are built is in the ``build`` directory, and because Waf knows the location of these libraries and executables, it is not necessary to install the libraries elsewhere. If users choose to install things outside of the build directory, users may issue the ``./waf install`` command. By default, the prefix for installation is ``/usr/local``, so ``./waf install`` will install programs into ``/usr/local/bin``, libraries into ``/usr/local/lib``, and headers into ``/usr/local/include``. Superuser privileges are typically needed to install to the default prefix, so the typical command would be ``sudo ./waf install``. When running programs with Waf, Waf will first prefer to use shared libraries in the build directory, then will look for libraries in the library path configured in the local environment. So when installing libraries to the system, it is good practice to check that the intended libraries are being used. Users may choose to install to a different prefix by passing the ``--prefix`` option at configure time, such as: :: ./waf configure --prefix=/opt/local If later after the build the user issues the ``./waf install`` command, the prefix ``/opt/local`` will be used. The ``./waf clean`` command should be used prior to reconfiguring the project if Waf will be used to install things at a different prefix. In summary, it is not necessary to call ``./waf install`` to use |ns3|. Most users will not need this command since Waf will pick up the current libraries from the ``build`` directory, but some users may find it useful if their use case involves working with programs outside of the |ns3| directory. One Waf ======= There is only one Waf script, at the top level of the |ns3| source tree. As you work, you may find yourself spending a lot of time in ``scratch/``, or deep in ``src/...``, and needing to invoke Waf. You could just remember where you are, and invoke Waf like this:: $ ../../../waf ... but that gets tedious, and error prone, and there are better solutions. If you have the full |ns3| repository this little gem is a start:: $ cd $(hg root) && ./waf ... Even better is to define this as a shell function:: $ function waff { cd $(hg root) && ./waf $* ; } $ waff build If you only have the tarball, an environment variable can help:: $ export NS3DIR="$PWD" $ function waff { cd $NS3DIR && ./waf $* ; } $ cd scratch $ waff build It might be tempting in a module directory to add a trivial ``waf`` script along the lines of ``exec ../../waf``. Please don't. It's confusing to new-comers, and when done poorly it leads to subtle build errors. The solutions above are the way to go. Testing |ns3| ************* You can run the unit tests of the |ns3| distribution by running the ``./test.py -c core`` script:: $ ./test.py -c core These tests are run in parallel by Waf. You should eventually see a report saying that :: 92 of 92 tests passed (92 passed, 0 failed, 0 crashed, 0 valgrind errors) This is the important message. You will also see the summary output from Waf and the test runner executing each test, which will actually look something like:: Waf: Entering directory `/path/to/workspace/ns-3-allinone/ns-3-dev/build' Waf: Leaving directory `/path/to/workspace/ns-3-allinone/ns-3-dev/build' 'build' finished successfully (1.799s) Modules built: aodv applications bridge click config-store core csma csma-layout dsdv emu energy flow-monitor internet lte mesh mobility mpi netanim network nix-vector-routing ns3tcp ns3wifi olsr openflow point-to-point point-to-point-layout propagation spectrum stats tap-bridge template test tools topology-read uan virtual-net-device visualizer wifi wimax PASS: TestSuite ns3-wifi-interference PASS: TestSuite histogram ... PASS: TestSuite object PASS: TestSuite random-number-generators 92 of 92 tests passed (92 passed, 0 failed, 0 crashed, 0 valgrind errors) This command is typically run by users to quickly verify that an |ns3| distribution has built correctly. (Note the order of the ``PASS: ...`` lines can vary, which is okay. What's important is that the summary line at the end report that all tests passed; none failed or crashed.) Running a Script **************** We typically run scripts under the control of Waf. This allows the build system to ensure that the shared library paths are set correctly and that the libraries are available at run time. To run a program, simply use the ``--run`` option in Waf. Let's run the |ns3| equivalent of the ubiquitous hello world program by typing the following:: $ ./waf --run hello-simulator Waf first checks to make sure that the program is built correctly and executes a build if required. Waf then executes the program, which produces the following output. :: Hello Simulator Congratulations! You are now an ns-3 user! **What do I do if I don't see the output?** If you see Waf messages indicating that the build was completed successfully, but do not see the "Hello Simulator" output, chances are that you have switched your build mode to ``optimized`` in the `Building with Waf`_ section, but have missed the change back to ``debug`` mode. All of the console output used in this tutorial uses a special |ns3| logging component that is useful for printing user messages to the console. Output from this component is automatically disabled when you compile optimized code -- it is "optimized out." If you don't see the "Hello Simulator" output, type the following:: $ ./waf configure --build-profile=debug --enable-examples --enable-tests to tell Waf to build the debug versions of the |ns3| programs that includes the examples and tests. You must still build the actual debug version of the code by typing :: $ ./waf Now, if you run the ``hello-simulator`` program, you should see the expected output. Program Arguments +++++++++++++++++ To feed command line arguments to an |ns3| program use this pattern:: $ ./waf --run --command-template="%s " Substitute your program name for ````, and the arguments for ````. The ``--command-template`` argument to Waf is basically a recipe for constructing the actual command line Waf should use to execute the program. Waf checks that the build is complete, sets the shared library paths, then invokes the executable using the provided command line template, inserting the program name for the ``%s`` placeholder. (I admit this is a bit awkward, but that's the way it is. Patches welcome!) Another particularly useful example is to run a test suite by itself. Let's assume that a ``mytest`` test suite exists (it doesn't). Above, we used the ``./test.py`` script to run a whole slew of tests in parallel, by repeatedly invoking the real testing program, ``test-runner``. To invoke ``test-runner`` directly for a single test:: $ ./waf --run test-runner --command-template="%s --suite=mytest --verbose" This passes the arguments to the ``test-runner`` program. Since ``mytest`` does not exist, an error message will be generated. To print the available ``test-runner`` options:: $ ./waf --run test-runner --command-template="%s --help" Debugging +++++++++ To run |ns3| programs under the control of another utility, such as a debugger (*e.g.* ``gdb``) or memory checker (*e.g.* ``valgrind``), you use a similar ``--command-template="..."`` form. For example, to run your |ns3| program ``hello-simulator`` with the arguments ```` under the ``gdb`` debugger:: $ ./waf --run=hello-simulator --command-template="gdb %s --args " Notice that the |ns3| program name goes with the ``--run`` argument, and the control utility (here ``gdb``) is the first token in the ``--command-template`` argument. The ``--args`` tells ``gdb`` that the remainder of the command line belongs to the "inferior" program. (Some ``gdb``'s don't understand the ``--args`` feature. In this case, omit the program arguments from the ``--command-template``, and use the ``gdb`` command ``set args``.) We can combine this recipe and the previous one to run a test under the debugger:: $ ./waf --run test-runner --command-template="gdb %s --args --suite=mytest --verbose" Working Directory +++++++++++++++++ Waf needs to run from its location at the top of the |ns3| tree. This becomes the working directory where output files will be written. But what if you want to keep those ouf to the |ns3| source tree? Use the ``--cwd`` argument:: $ ./waf --cwd=... It may be more convenient to start with your working directory where you want the output files, in which case a little indirection can help:: $ function waff { CWD="$PWD" cd $NS3DIR >/dev/null ./waf --cwd="$CWD" $* cd - >/dev/null } This embellishment of the previous version saves the current working directory, ``cd``'s to the Waf directory, then instructs Waf to change the working directory *back* to the saved current working directory before running the program.