I need to know the root cause of the segmentation fault (SIGSEGV), and how to handle it.
7 Answers
SigSegV means a signal for memory access violation, trying to read or write from/to a memory area that your process does not have access to. These are not C or C++ exceptions and you can’t catch signals. It’s possible indeed to write a signal handler that ignores the problem and allows continued execution of your unstable program in undefined state, but it should be obvious that this is a very bad idea.
Most of the time this is because of a bug in the program. The memory address given can help debug what’s the problem (if it’s close to zero then it’s likely a null pointer dereference, if the address is something like 0xadcedfe then it’s intentional safeguard or a debug check, etc.)
One way of “catching” the signal is to run your stuff in a separate child process that can then abruptly terminate without taking your main process down with it. Finding the root cause and fixing it is obviously preferred over workarounds like this.
Segmentation fault arrives when you access memory which is not declared by the program. You can do this through pointers i.e through memory addresses. Or this may also be due to stackoverflow for example:
void rec_func() {int q = 5; rec_func();}
int main() {rec_func();}
This call will keep on consuming stack memory until it's completely filled and thus finally stackoverflow happens. Note: it might not be visible in some competitive questions as it leads to timeouterror first but for those in which timeout doesn't happens its a hard time figuring out SIGSEGV.
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