C++ Signal Handling
Signals are interrupts of software which is delivered to a process by the operating system. Signals can also be issued by the OS on the basis of system or error condition. Programmers can generate interrupts by pressing Ctrl+C on a UNIX, LINUX, Mac OS X or Windows system. There is some default behavior for some but in this chapter, you will learn about how to handle the signals and manage them properly.
Signals are interrupts of software which is delivered to a process by the operating system. Signals can also be issued by the OS on the basis of system or error condition. Programmers can generate interrupts by pressing Ctrl+C on a UNIX, LINUX, Mac OS X or Windows system. There is some default behavior for some but in this chapter, you will learn about how to handle the signals and manage them properly.
Some signals are there which cannot be caught by the program but there is the list of signals which programmers can in the program and take adequate actions based on the signal. The signals are defined <csignal> header file.
Here is a lists of signals along with their description and working capability:
The signal() function
The signal-handling library of C++ provides function signal to trap unexpected event. The syntax of signal function is:
Syntax:
void (*signal(int sig, void (*func)(int)))(int);
This function is set to handle signal. It specifies a way to handle the signals with the signal number specified by sig. Parameter func specifies one of the three ways in which a signal can be handled by a program:
Here is a simple C++ program where we will catch SIGINT signal using signal() function.
Example:
#include <iostream>
#include <csignal>
using namespace std;
sig_atomic_t signaled = 0;
void my_handler (int param)
{
signaled = 1;
}
int main ()
{
void (*prev_handler)(int);
// register signal SIGINT with handler
prev_handler = signal (SIGINT, my_handler);
raise(SIGINT);
cout<< "signaled is: " << signaled;
}
Comments
Post a Comment