Write a C program that does not terminate when Ctrl+C is pressed

In this section we will see how to write a program in C that cannot be terminated by the Ctrl + C key.

The Ctrl + C generates the keyboard interrupt, and it stops the execution of the current process. Here when we will press the Ctrl + C key, it will print a message then continues the execution. To use this functionality, we will use the signal handling technique in C. When the Ctrl + C is pressed it generates SIGINT signal. There are some other signals and their functionalities in the following list.

Here we will use the standard C library function signal() to handle these signals.

Example Code

#include <stdio.h>
#include <signal.h>
void sigint_handler(int signum) { //Handler for SIGINT
   //Reset handler to catch SIGINT next time.
   signal(SIGINT, sigint_handler);
   printf("Cannot be stopped using Ctrl+C 
");
   fflush(stdout);
}
main () {
   signal(SIGINT, sigint_handler);
   while(1) { //create infinite loop
   }
}

Output

Cannot be stopped using Ctrl+C
Cannot be stopped using Ctrl+C