int main (void) { char buf[8]; to_octal(010644, buf, 6); if (buf[1] != '1') abort(); return 0; }
void main() { char binary[100],octal[100]; int k; printf("enter a binary number\n"); scanf("%s",binary); k=valid(binary); if(k==0) { printf("invalid input"); exit(0); } to_octal(binary,octal); }