Many programming languages provide at least one utility function for accessing operating system commands.
C provides one such function, called system.
The system function can be used to call all types of UNIX or DOS commands from within C program code.
For instance, you could call and execute any of the UNIX commands: man, ps, pwd.
The general example for programmers of text-based languages, such as C, is how to clear the computer’s screen. One solution is shown next.