When a program dumps core, we have set our `kernel.core_pattern` to put the core file in a particular location with a certain filename etc.

```
kernel.core_pattern = | /var/core_file_handler.py %e %s %p %lu %g %t

```

Here is the destination directory, and a sample core file:

```
$ ls -l /var/cores
drwxr-xr-x 2 root root 4.0K Mar 23 09:42 app

$ ls -l /var/cores/app/
-rw-r--r-- 1 root root 60510208 Mar 23 09:42 2016.03.23_09.42.14.867727_11_SIGSEGV_u

```

**CentOS 6.7**

On CentOS 6.7 I have bash 4.1.2 and gdb 7.5

```
$ bash --version
GNU bash, version 4.1.2(1)-release (x86_64-redhat-linux-gnu)

$ gdb --version
GNU gdb (GDB) Red Hat Enterprise Linux (7.5.0.20120926-26.el6)

```

When I want to open a core file, I can type gdb and then *tab complete* the path and the core file

```
gdb ./app /var/cores/app/201.... <tab> 

```

This will successfully tab complete the core file name.

**Ubuntu 14.04**

On Ubuntu 14.04 I have bash 4.3.11 and gdb 7.7.1

```
$ bash --version
GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)

$ gdb --version
GNU gdb (Ubuntu 7.7.1-0ubuntu5~14.04.2) 7.7.1

```

When I want to open a core file, I can type gdb and then *tab complete* the path, but **not the core file**

```
gdb ./app /var/cores/app/  <tab> <tab> <tab>....

```

This will **not tab complete the core file name**. It just gets stuck at `/var/cores/app/` and won't go any further

* Access permissions on `/var/cores/app` is the same on both machines
* Access permissions on `/var/cores/app/core_file` is the same on both machines

**Question:**

Why can I *tab-complete* the core-file-name on CentOS but not on Ubuntu?