Enable Core Dump in current working directory for C/C++ programs on Ubuntu 16.x

Check the '/proc/sys/kernel/core_pattern' file

    cat /proc/sys/kernel/core_pattern

if the output of above command is

    |/usr/share/apport/apport %p %s %c %P

then you need to edit the 'core_pattern' file and replace

    |/usr/share/apport/apport %p %s %c %P

with

    core.%e.%p

to do this by below command

sudo su -c 'echo "core.%e.%p" > /proc/sys/kernel/core_pattern'

it will ask you for root password, and its done. At the string 'core.%e.%p' %e means the executable file name and %p denotes the processID. Now to test the core dumping first run below command

ulimit -c unlimited

then compile below code and run it.
test.c
 #include<stdio.h>  
 int main()  
 {  
      char buff[20];  
      int i;  
      for(i=0;i<40;i++) {  
           buff[i] ='\x41';  
      }  
 }