Exception Un Caught in C++

[Girish Kanakagiri]

Hi

int i = 0;
try
{
   MyCls as(param1, param2)
   i = as->kpy->size();
}
catch(CError &)
{
}
 

if as is having null value then why catch block is
not catching Null exception thrown ?

Will a null Exception be thrown in try block ?

Can anyone explain this ?

Don't tell me about catch(...), which catches all the
exception. Please clear me with the situation which is
mentioned in the code.

Please reply to the earliest.

Regards,
Girish.

[Banfa]

The problem is that NULL pointer and invalid memory accesses (segmentation faults) are not generated by the program (like normal exceptions) but are generated externally by the system which signals the program.

If you want to catch them you have to intercept the signal from the system and handle it something like this

#include <iostream>
#include <string>
#include <signal.h>
 
using namespace std;
 
void SEGV_handler(int i)
{
    cout << "Oops" << endl;
    throw string("SEGV");
}
 
int main(int argc, char **argp)
{
    char *p = 0;
 
    signal(SIGSEGV, SEGV_handler);
 
    try
    {
        *p = 'a';
    }
    catch(string s)
    {
        cout << "Exception Caught: " << s << endl;
    }
 
    return 0;
}
 

Notice that I catch a string because I throw a string.

Look up signal.

[Girish Kanakagiri]

The problem is that NULL pointer and invalid memory accesses (segmentation faults) are not generated by the program (like normal exceptions) but are generated externally by the system which signals the program.

If you want to catch them you have to intercept the signal from the system and handle it something like this

#include <iostream>
#include <string>
#include <signal.h>
 
using namespace std;
 
void SEGV_handler(int i)
{
    cout << "Oops" << endl;
    throw string("SEGV");
}
 
int main(int argc, char **argp)
{
    char *p = 0;
 
    signal(SIGSEGV, SEGV_handler);
 
    try
    {
        *p = 'a';
    }
    catch(string s)
    {
        cout << "Exception Caught: " << s << endl;
    }
 
    return 0;
}
 

Notice that I catch a string because I throw a string.

Look up signal.

Thanks a lot Banfa, You gave me the exact answer for which
I was trying all the time in Google.

It really helped me a lot. Thanks again.

Regards,
Girish.