C language subtitles rolling effect from left to right

#include <stdio.h>
#include <string.h>
#include <windows.h>
 
int main()
{
    char str[100] = "HELLO WORLD! GOOD BYE!";
    int i,j;
	while(1)
	{
		for(i=0;i<strlen(str);i++)
		{
			system("cls");
			for(j=i;j<strlen(str);j++)
			{
				printf("%c",str[j]);
			}
			Sleep(100);
			printf("\n");
		}
	}
    return 0;
}

system ( "CLS") is a C language program call the system command cls clear the screen to complete the operation. 
system ( "time / t") ; the display time 
system ( "dir"); // column directory 
system ( "pause"); resident achieved.

system function is a function of the operating system and language provide convergence C, the following function prototype:

#include <stdlib.h> // where header 
int system (const char * command) ; // parameters for the operating system commands 
Functions Function: execute a shell command execute an operating system command