ex_signals.c

 
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include <errno.h>
#include <signal.h>
#include <assert.h>
 
#include "nilorea/n_signals.h"
#include "nilorea/n_log.h"
 
#include <libgen.h>
 
 
int  divide_by_zero(void);
void cause_segfault(void);
int stack_overflow(void);
void infinite_loop(void);
void illegal_instruction(void);
void cause_calamity(void);
 
char *progname = NULL ;
 
int main( int argc, char * argv[])
{
    (void)argc;
    progname = argv[ 0 ];
 
    //set_log_file( "ex_signals.log" );
    set_log_level( LOG_DEBUG );
    set_log_level( LOG_STDERR );
    //set_log_level( LOG_FILE );
 
    n_log( LOG_DEBUG, "set_signal_handler" );
    set_signal_handler( basename( progname ) );
 
    n_log( LOG_DEBUG, "cause_calamity" );
    cause_calamity();
 
    return 0;
}
 
void cause_calamity(void)
{
    /* uncomment one of the following error conditions to cause a calamity of
       your choosing! */
    stack_overflow();
    (void)divide_by_zero();
    cause_segfault();
    assert(false);
    infinite_loop();
    illegal_instruction();
}
 
 
 
int divide_by_zero(void)
{
    int a = 1;
    int b = 0;
    return a / b;
}
 
void cause_segfault(void)
{
    int * p = (int*)0x12345678;
    *p = 0;
}
 
int stack_overflow(void)
{
    int foo = 0 ;
                (void)foo;
                foo = stack_overflow();
                return rand()%1000 ;
}
 
/* break out with ctrl+c to test SIGINT handling */
void infinite_loop(void)
{
    int a = 1 ;
    int b = 1 ;
    int c = 1 ;
    while( a == 1 )
    {
        b=c;
        c=a;
        a=b;
    }
}
 
void illegal_instruction(void)
{
    /* I couldn't find an easy way to cause this one, so I'm cheating */
    raise(SIGILL);
}