Mua-Xuan-2016---Lop-May-Vi-Tinh-53-Bai-2

//Removes \n if ((strlen(line)>0) && (line[strlen(line) - 1] == '\n')) line[strlen(line) - 1] = '\0';

if (strstr(line, "quit") != NULL || strstr(line, "quit ") != NULL || strstr(line, "quit\t") != NULL || strstr(line, " quit") != NULL || strstr(line, "\tquit") != NULL)