Is there any library similar to <conio.h>?

It looks like you need to use the curses.h file instead. See here : https://stackoverflow.com/questions/8792317/why-cant-i-find-conio-h-on-linux

You may look at https://github.com/pushkar6723/conio4gcc

Note that this is only compatible file. I recommend to shift on curses.h file, which has lot many things, which are absent in conio.h file.

the best way, is create a symlink between curses.h and conio.h like:

ln -s /usr/include/curses.h /usr/include/conio.h

then you can use

#include <curses.h>
or 
#include <conio.h>

if you don't have curses.h

# debian/ubuntu
$ sudo apt-get install libncurses5-dev libncursesw5-dev
# voidlinux
$ xbps-install -S ncurses-devel
# archlinux
$ pacman -Sy ncurses
# redhate/fedora/suse...
$ sudo yum install ncurses-devel