kapilkumar,
Cracking, hacking, and security penetration testing are not limited to writing code to perform those tasks. Individuals involved in those activities tend to use a variety of tools. If you are looking to:
- displaying the details of underlying protocols
- display the protocol header and structure details
then you are probably going to need network analysis tools such as a network packet sniffer and/or protocol analyzer. The above two items might be the same thing, be parts of a single tool, or be separate tools. There are lots of free tools for Linux to perform the above tasks. Do a Google search on the above items to learn more about them.
Creating a new protocol is much like creating any new system, which is going to start with a specification and/or design document and then develop from there. Creating a protocol isn't dependent on a specific programming language or development tool.
Network programming tends to be socket programming or writing code that makes use of sockets. The good thing about socket programming is that sockets are very similar to regular files and the interaction with sockets in code is very similar to the interaction with files in code. For example, in C/C++/Java there are facilities to do the following with files:
- create or open
- read
- write
- close
There are similar facilities in C/C++/Java to create, open, read, write, close, and manage connections with sockets.
I'm a long time Borland products user as well. Borland produced some great products. However, the Turbo C++ (TC++) is an
ancient product. I first used TC++ for DOS in 1989 or 1990. Even though TC++ was great, Borland introduced many non-standard extensions to the C++ language in their product. The "conio.h" file is a Borland specific proprietary file for doing console IO in MSDOS and Windows. Also, the version of the standard C++ that TC++ was based on has been revised and improved.
It would be best to focus on the current standard version of C++. Your experience with TC++ will allow you to get up to speed quickly. After all its still C++.

The GNU C/C++ compiler is free and available on all distros. of Linux. There are lots of text editors available on Linux and there are IDEs similar to the TC++ environment. There are many good books for C, C++ and Java. Search this site for recommendations. I believe Wigry has provided some good info. on where/how Java is used and how to get into that market.