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-   -   how to set path? here a meet the problem with ns2 installation (http://www.linuxquestions.org/questions/linux-newbie-8/how-to-set-path-here-a-meet-the-problem-with-ns2-installation-265954/)

cain_eve 12-13-2004 12:36 PM

how to set path? here a meet the problem with ns2 installation
 
Hi, I just install network simulator 2. The process is so long and at the end It shows something I must do. I think it is like to set a PATH for java in windows. But I don't know how to command.
The screem of final result is as follows,
Please put /usr/local/src/ns-allinone-2.27/bin:/usr/local/src/ns-allinone-2.27/tcl8.4.5/unix:/usr/local/src/ns-allinone-2.27/tk8.4.5/unix
into your PATH environment; so that you'll be able to run itm/tclsh/wish/xgraph.
IMPORTANT NOTICES:

(1) You MUST put /usr/local/src/ns-allinone-2.27/otcl-1.8, /usr/local/src/ns-allinone-2.27/lib,
into your LD_LIBRARY_PATH environment variable.
If it complains about X libraries, add path to your X libraries
into LD_LIBRARY_PATH.
If you are using csh, you can set it like:
setenv LD_LIBRARY_PATH <paths>
If you are using sh, you can set it like:
export LD_LIBRARY_PATH=<paths>

(2) You MUST put /usr/local/src/ns-allinone-2.27/tcl8.4.5/library into your TCL_LIBRARY environmental
variable. Otherwise ns/nam will complain during startup.

(3) [OPTIONAL] To save disk space, you can now delete directories tcl8.4.5
and tk8.4.5. They are now installed under /usr/local/src/ns-allinone-2.27/{bin,include,lib}

After these steps, you can now run the ns validation suite with
cd ns-2.27; ./validate

visaris 12-13-2004 12:39 PM

In a generic way, if you want to add somthing to your path you can do this (bash):

Code:

export PATH=$PATH:/new/path/to/add/here/
You may want to add a line like that to your ~/.bashrc file so your path will be set up correctly all the time.

cain_eve 12-13-2004 01:38 PM

Thanks visaris
I dont't know what's the meaning of /.bashrc
what is this file useful and where can I find it or just creat a new one under root or the ns2file?

cain

cain_eve 12-13-2004 01:45 PM

by the way, what is and what is the differences of csh and sh?
where is the location of LD_Library_PATH and TCL_LIBRARY?
many thanks

visaris 12-13-2004 01:46 PM

The file '.bashrc' is a file that contains commands which are to be run automatically after bash starts up. For example, if your username is "foo" and you placed

Code:

echo 'Welcome to Linux, foo!'
at the end of your /home/foo/.bashrc file, you would be greeted by "Welcome to Linux, foo!" every time you logged in or started a new xterminal.

Once you have your export lines set up correctly, you can place them in your user's ~/.bashrc file, and then everytime you start a new xterm, the required environment variables will be set up for you, and you can then run your ns2 or whatever.

cain_eve 12-13-2004 02:02 PM

seems more clear
so the filename is just .bashrc
when I install a new system there is no such file yet?
as I'm a beginner
I will search for some similar thread.
thanks.

cain

visaris 12-13-2004 02:03 PM

LD_Library_PATH and TCL_LIBRARY are environment variables just like PATH is. To get a list of all your current variables and their values type in 'env'.

To set a variable to a value do:
Code:

export YOUR_VAR_HERE=your_value_here
To add something to the end of a variable do:
Code:

export YOUR_VAR_HERE=$YOUR_VAR_HEREyour_value_to_add_here

cain_eve 12-13-2004 02:10 PM

Oh I see
HOME=/root
BASH_ENV=/root/.bashrc
LOGNAME=root
the file is hide?

cain_eve 12-13-2004 02:11 PM

how to see hide file?

visaris 12-13-2004 02:14 PM

Well, the environment variables aren't really stored in a file. At least, I don't think so. They are stored in your shell's memory. Sort of like internal values/settings.

If you're asking about the .bashrc file, that is hidden from the ls output. To find all the '.' files do a "ls -al" and that should list all of them. If you do not have a .bashrc file, you can always make one.

cain_eve 12-13-2004 02:23 PM

Oh I read the ls man file.
Your replies are very important to me. Thanks a lot.

boydasilva 12-16-2004 05:31 PM

Don't mean to hijack here, but is there any way to remove a path once it has been exported in the .bashrc file? I've made a mistake and I don't seem to be able to change it.

cain_eve 12-16-2004 06:09 PM

I think just modify the .bashrc file
vi .bashrc
and remove the export line


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