flying.c

/*C program to design flying characters Screen Saver.*/ 
#include <stdio.h>
#include <termios.h>
#include <unistd.h>
#include <fcntl.h> 
/*will return character based on passed number*/
char getCHAR(int n)
{     char ok[] = "~!@#$%^&*:;'\",{}|<>=";     return ok[n];
} 
/*function to identify that any key hit by the keyboard*/
int kbhit(void)
{     struct termios oldt, newt;     int ch;     int oldf;      tcgetattr(STDIN_FILENO, &oldt);     newt = oldt;     newt.c_lflag &= ~(ICANON | ECHO);     tcsetattr(STDIN_FILENO, TCSANOW, &newt);     oldf = fcntl(STDIN_FILENO, F_GETFL, 0);     fcntl(STDIN_FILENO, F_SETFL, oldf | O_NONBLOCK);      ch = getchar();      tcsetattr(STDIN_FILENO, TCSANOW, &oldt);     fcntl(STDIN_FILENO, F_SETFL, oldf);      if (ch != EOF) {         ungetc(ch, stdin);         return 1;     }      return 0;
} 
/*move cursor on specified position on screen*/
void gotoxy(int x, int y)
{     printf("%c[%d;%df", 0x1B, y, x);
} 
int main(void)
{     int x, y;     long int i, j;     i = j = 0;      x = 1;     y = 20;     system("clear");      /*program will run until any key hit*/     while (!kbhit()) {         x = rand() % ((150 - 1 + 1) + 1);         y = rand() % ((50 - 1 + 1) + 1);         gotoxy(x, y);         printf("%c", getCHAR(rand() % ((20 - 1 + 1) + 1)));         fflush(stdout);         ++i;         if (i == 10000) {             ++j;             i = 0;         }         if (j == 100000) {             i = 0;         }         if (j <= 100)             usleep(30000);         if (j <= 1000)             usleep(3000);         if (j <= 10000)             usleep(300);     }     return 0;
}