Simple Command Prompt Dengan Bahasa C

#include <stdio.h>
#define CLEAR_SCREEN system("cls")
#define CHANGE_TITLE system("title Simple Command Prompt");
int main() {
	CHANGE_TITLE;
	CLEAR_SCREEN;
	printf("\n\tWelcome to simple command prompt coded by %s\n\tType\
\"help\" for available command\n\n","ilmusoft.com");
	run();
}
int run() {
	char input[512];
	char command[512];
	printf("Run:> ");
	gets(input);
	if (strcmp(input,"ping")==0){
		char host[512];
		printf("Type destionation host: ");
		scanf("%s",host);
		sprintf(command,"ping %s",host);
		system(command);

	}
	else if(strcmp(input,"quit")==0 || strcmp(input,"q")==0){
		exit(0);
	}
	else if(strcmp(input,"whoami")==0){
		system("whoami");
	}
	else if(strcmp(input,"help")==0){
        printf("Available command:\n\
        whoami\tprint current user\n\
        ping\tsend ping request\n\
        q\tquit from this console\n\
        help\tprint this info\n");
	}
	run();
}