I want to put license details and conditions between show c and show w command, as my program has the interactive prompt.
You are referring to the section How to Apply These Terms to Your New Programs in https://www.gnu.org/licenses/gpl-3.0.en.html (GPL 3.0). The relevant section reads as follows:
<program> Copyright (C) <year> <name of author>
This program comes with ABSOLUTELY NO WARRANTY; for details type `show w`.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c` for details.
The hypothetical commands show w and show c should show the
appropriate parts of the General Public License. Of course, your
program's commands might be different; for a GUI interface, you would
use an “about box”.
The hypothetical command 'show w' is implied to show information about warranty, and the hypothetical command 'show c' is implied to show information about copying. Keep in mind that this section is not part of the actual GPL license (it comes after "END OF TERMS AND CONDITIONS"), so it is more of a suggestion. As an example, the GNU Octave program, version 3.0.5 interprets the above as follows:
GNU Octave, version 3.0.5 Copyright (C) 2008 John W. Eaton and others.
This is free software; see the source code for copying conditions.
There is ABSOLUTELY NO WARRANTY; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. For details, type `warranty'.
...
Typing 'warranty' gives a slightly more elaborated version of the information in the above paragraph, the statement "You should have received a copy of the GNU General Public License along with this program," and a link to the GNU.org licenses page in case the license was not present for some reason. In Octave there is no 'copying' command, as would be suggested by hypothetical 'show c' command, but as mentioned, it is not actually a requirement to provide that.
