[os] Signal Mangement with sigaction - SINGINT ( CTRL-D ) SAMPLE

[xgiovio]

#include <signal.h>
#include <st***.h>
#include <stdlib.h>

/***
 *               _            _                          
 *              (_)          (_)                          
 *    __  ____ _ _  _____   ___  ___   ___ ___  _ __ ___  
 *    \ \/ / _` | |/ _ \ \ / / |/ _ \ / __/ _ \| '_ ` _ \
 *     >  < (_| | | (_) \ V /| | (_) | (_| (_) | | | | | |
 *    /_/\_\__, |_|\___/ \_/ |_|\___(_)___\___/|_| |_| |_|
 *          __/ |                                        
 *         |___/                                          
 *
 *  Alter SIGINT signal from shell. It will ask you if you are sure
 *  to kill the process.
 *
 *  v 1.0
 *
 *
 */


void xflush ( FILE* stream ) {
    
    int temp;
    temp = fgetc ( stream );
    
    for (; temp != '\n' ;temp = fgetc ( stream )){}
    
    
}



void ask ( int signal) {
    
    char * stringa;
    
    stringa = (char *) malloc (20);
    
    if ( stringa == NULL) { fprintf(stderr,"Impossibile completarel'operazione\n");exit(-2);}
    
    fprintf ( stdout, "\nDo you want to quit me? y\\n\n");
    fscanf( stdin, "%19s", stringa);
    xflush (stdin);
    
    for (;(strcmp(stringa,"y") != 0) &&  (strcmp(stringa,"n") != 0);){
    
        fprintf ( stdout, "Wrong Answer \n");
        fscanf( stdin, "%19s", stringa);
        xflush (stdin);
    }
    
        if ( strcmp(stringa,"y") == 0){
            fprintf(stdout,"Signal processed. Goodbye friend. I'm dying ...\n");
            kill (getpid(),SIGKILL);
            fprintf(stderr, "You can't kill me!\n");
        }
    
}



int main ( void ) {
    
    struct sigaction sigint_action;
        sigint_action.sa_handler = ask;
        sigint_action.sa_flags = 0;
        
    
    sigaction ( SIGINT, &sigint_action, NULL);
    
    fprintf(stdout,"Press ctrl-c if you want to kill me....\n");
    
    for(;-1;){
        pause ();
        fprintf(stdout,"Signal processed but i'm still here. Thank you. Press ctrl-c if you want to kill me\n");
    }
      
    
    return 0;
}