below is one of my function call of a program done in C:

/* asks if the players would like to have another game of Tic Tac Toe */
void prompt_user(int game[])
char reply;

printf("\nPlay Again? (Y/N): ");
scanf("%c", &reply);

if(reply == 'Y' || reply == 'y')

else if(reply == 'N' || reply == 'n')
printf("Hope You Have Enjoyed The Game!\n\n");
exit(0); /* quits the game */

when using microsoft visual C++ and devC++ to compile and execute, there were no errors in the output when playing the tic-tac-toe game.

however, when i used my school's lab (which is using Linux and xemacs only) pc to compile and execute, the output did not allow me to enter Y or N as an answer to 'Play Again?'. The execution exits immediately. anyone knows the reason and how to solve my problem??


I think your bug has to do with the reply definition. You are making two dangerous assumptions with your code... 1) is that char reply; properly initializes the variable (instead of you making an explicit definition, such as reply='s'; so that you know what that variable holds. 2) Your code makes no provision if someone enters in something else, such as the letter 'T' If I were to enter in 'T', neither of your if statements will work, as they fail the tests, and the function will exit without the exit code.

My GUESS is that you might have an extra character coming through the function, and the computer is seeing that as valid input. Granted, the code does not bring in any data except for the one integer, but what is in the character buffer?