Possible Duplicate:
Why core dump file is generated ?
When my programs segfault, I get this message on stderr:
Segmentation fault
Sometimes, however, I see this instead:
Segmentation fault (core dumped)
What is the 'core'? Is it useful for debugging? What triggers it to be dumped? Where are these dumps located?
A core dump is basically a snapshot of the computer memory when the program crashed.
http://en.wikipedia.org/wiki/Core_dump
It could be many things that limit the core dump, from ulimit... http://www.akadia.com/services/ora_enable_core.html
To C runtime settings.
Look for cores in /cores.
I may be wrong, but I think that it depends on whether a program is compiled to enable debugging whether you get a core dump.
gdb is the standard gcc debugger; you can sometimes get a hint of what happened without having to be a serious programmer.