need to know tcl script programming

Set the environment variables in .bash_profile in the home directory of the user(the directory in which you are in after the login process). It is a hidden file so to see the file use

#ls –a

edit it using vi editor

#vi .bash_profile

add the necessary environment variables
(refer the last pages of install script of ns2 – the file ns-allinone-2.28ns-2.28 install)

If you do it properly, then xgraph and other executables of ns2 can be accessed from any diroctory.

To show a graph for two column data file test.dat, run the command as follows.

#xgraph test.dat