How to involve system functions like notifications, alert, and somewhat like that in C program?
Welcome to PF!
It would help if you described the environment of the program. Is this on a laptop, desktop or mobile platform.
For android, there are apis that you can call to get access to system features.
For normal java programs, programmers access the System class or the Runtime class to get access to OS features.
I want to call system functions of windows in C.
Google "Windows API"
Separate names with a comma.