Block Control Characters

I'm making a payroll application which takes input from cin, it validates the data (has a while loop in it). The problem is if I 'accidently' press Ctrl+Z it just keeps looping the prompt on the screen as I am locked out of the program. what canI do to block these special characters Ctr+Z and Ctrl+C and if there are others?

ctrl+z and ctrl+c are "EOF" some where in your program you are telling it to ignor them. In your test condition add a test for EOF to break your
loop.

how can i do that? the code im delaying with is :

Code:

---

do {
      cout << "Enter data: ";
      cin >> data}
while (!validData);
}

---

Code:

---

cout << "Enter data: ";
while(cin >> data) {
  if(valid) {
  } else break;
    cout << "Enter data: ";
}

---

in 'ctype' header, there are functions like 'isalnum()', 'isdigit', etc which you can use to check for valid input or create one your self using the ascii chart...

we are suppose to use a do while loop because we are only suppose to prompt once! Our lecturer said prompting for the samething more than once was 'inefficient', so I can't use

Code:

---

cout << "Enter data: ";
while(cin >> data) {
if(valid) {
} else break;
cout << "Enter data: ";
}

---

would that even stop the control characters? i don't quite see how...

ctrl-z is the end of file marker for terminal input
ctrl-c is the interrupt signal, which kills your program unless you handle or ignore it

Code:

---

#include <iostream>
#include <string>
#include <signal.h>
using namespace std;

volatile bool sigCaught = false;
// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/_CRT_signal.asp
void catcher ( int signal ) {
  sigCaught = true;
}

int main ( ) {
  bool  done = false;
  /* catch ctrl-C, test sigCaught below if you want to know about it */
  // signal ( SIGINT, catcher );
  /* ignore ctrl-C */
  signal ( SIGINT, SIG_IGN );

  while ( !done ) {
    char input[100];
    while ( !done &&
            cin.getline(input,sizeof input) ) {
      string sInput = input;
      cout << sInput << endl;
      if ( sInput == "exit" ) {
        done = true;
      }
    }
    if ( cin.eof() ) {
      cin.clear();
      cout << "EOF detected, ignored" << endl;
    }
  }

  return 0;
}

---

ok i figured out the cin.eof by myself. thanks a lot for the signal part!