I've installed two versions of ns2,the process of calling a the version you want to use is that you use source command along with the relevant environment variables file which in my case is bash_profile1 and then ./configure.
My code is as follows:
Why do I get the above error?

Welcome to LQ.

There is usually no './configure' to be done,
when a version of ns-allinone-2.xx has been installed.
( Unless you have added a patch.)

And : The command ./configure can only be used, when a script
by name "configure" is present in the current directory.

What is it you want to "configure" ? ?

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Probably I've not made the post clear actually I've two versions of NS2 installed and I followed the simple instructions given in the following link to choose which version to use:

http://ramakrishnamundugar.blogspot....single-os.html

# 3 : May work with statement "a)" : source ~/.bash_profile1
The following " b) c) d) e) " are irrelevant : Please ignore.
→ → Things that people write in a blog may be meaningless.

./configure, make, 'make install' are used for other tasks.
But never in the order shown in that link.


Another method of having more than one version of ns-allinone-2.xx :
Make copies of the binary 'ns' to different names.
Like : cd ns-allinone-2.29/ns-2.29/ && cp ns ns229
Or : cd ns-allinone-2.34/ns-2.34/ && cp ns ns234
.. Then : sudo cp ns229 /usr/local/bin/ && sudo cp ns234 /usr/local/bin/
.. And the binaries are always in a PATH :
No entries to the .bash_profile are required. Ever.
The binary ns** are hard coded to know the locations of their libraries.

Using : Type e.g. ns229 or ns234, instead of plain 'ns'.


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Thankyou Sir.