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Get your own copy of NS

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• Location of the NS Source files
  • /home/cheung/NS/src - NS source directory

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• Get a copy of NS in your project directory
  • First, make an NS directory in your project directory:
    mkdir ~/cs558/NS

  • Next, make a duplicate NS distribution in ~/cs558/NS using the following command:
    /home/cs558000/bin/dup-ns

    Inside ~/cs558/NS, you will have symbolic links to the actual source files. (Most of the sources will be unchanged, so symbolic links are the most efficient way to make a duplicate distribution)

  • NOTE: you don't have permission to change any of the source code because the file is a symbolic link

    Read the next section if you need to make changes to a file

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• Changing an existing source file
  • You need to replace a symbolic link with a real copy of a file if you need to make changes to the file (because the file is read-only).

  • I have written a shell-script to perform this common task.

  • If you need to update a file named FILENAME, then use the following command to replace the symbolic name with a real copy:
    /home/cheung/NS/bin/mk-copy       FILENAME       ALIAS

    The parameter ALIAS will be explained next.

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  • Often, you need to make changes to several files in different directories

    It is hard to keep track of all the files that has been changed.

  • I tried to help you manage the changes in the files with a feature in the /home/cheung/NS/bin/mk-copy command:

    The command

    /home/cheung/NS/bin/mk-copy       FILENAME       ALIAS

    will also create a symbolic name called ALIAS inside the ~/cs558/NS/00-newcodes directory that points to the real file copy.

  • You can use this symbolic link in the following ways:
    • You can edit the actual file through the symbolic name - in other words, all the files that contains changes can be accessed from a single directory ~/cs558/NS/00-newcodes

    • You can use ls -l to see which files in the NS distribution have been changed.

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• Adding a new source file
  • You can add a new program file to NS, but I receommend that you organize your files well - because there are so many files in NS already.

  • Some like to put their news inside existing NS directories.

    This approach has the advantage that related codes are found in one place.

    But it makes it very hard to find your new code (especially after some time).

  • I prefer to put new code (which are not part of the NS distribution) in a separate directory.

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  • I would do the following:
    • Create a directory ~/cs558/NS/01-newfiles

    • Put all new program files in there

    • Add a symbolic link in ~/cs558/NS/00-newcodes to allow you to access your files from within one single directory (makes editing changes easier).

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  • When you add a new program file to NS, you need to edit NS's Makefile to tell the Make utility to include your program file in the compilation.

  • To include your program file named PROGFILE.cc (which has a symbolic reference in ~/cs558/NS/00-newcodes) in the NS's Makefile , do:
    1. edit ~/cs558/NS/Makefile

    2. find the string OBJ_CC = \

    3. Add the line:

       OBJ_CC = \ 01-newcodes/PROGFILE.o \ .... (other lines in Makefile)

       Make very certain that the "\" character is the last character in the line !!!

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• Compiling NS
  • Do the following to compile a new NS simulator:
    • cd ~/cs558/NS
    • make

  • The NS simulator is the file ~/cs558/NS/ns