How to Save Core Dumped FIle

Whenever you encounter the error message:
Segmentation fault (core dumped)

you may be wondering where is this core file?

Well, it is most likely that you need to increase the core file size. Try
$ ulmit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 63344
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 63344
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

You see, the core file size is set as 0 by default in Ubuntu, and that's why you are not seeing the core dumped file. Increase this to, say, 50000:
$ ulimit -c 50000

Now, you should see a core file as core in the current directory whenever you encounter the above error message!