C++ LANGUAGE SIGNAL() FUNCTION

COMPUTER LANGUAGES HTML,C,C++.JAVA,.NET AND MULTIMEDIA basics and programs click home button

C++ LANGUAGE SIGNAL() FUNCTION

The signal() Function 

C++ signal-handling library provides function signal to 
trap unexpected events. Following is the syntax of the 
signal() function: 

void (*signal (int sig, void (*func)(int)))(int); 
 
Keeping it simple, this function receives two arguments: first 
argument as an integer, which represents signal number and second 
argument as a pointer to the signal-handling function. 

36. SIGNAL HANDLING 
#include <iostream> 
#include <csignal> 
 
using namespace std; 
 
void signalHandler( int signum ) 
{ 
    cout << "Interrupt signal (" << signum << ") received.\n"; 
 
    // cleanup and close up stuff here   
    // terminate program   
 
   exit(signum);   
 
} 
 
int main () 
{ 
    // register signal SIGINT and signal handler   
    signal(SIGINT, signalHandler);   
 
    while(1){ 
       cout << "Going to sleep...." << endl; 
       sleep(1); 
    } 
 
    return 0; 
} 
When the above code is compiled and executed, it produces the following result: 
Going to sleep.... 
Going to sleep.... 
Going to sleep.... 
Now, press Ctrl+C to interrupt the program and you will see 
that your program will catch the signal and would come out by printing something as follows: 


Going to sleep.... 
Going to sleep.... 
Going to sleep.... 
Interrupt signal (2) received.