I wrote a playbook with the purpose of changing the last bit of the default gateway ip of all the hosts in my inventory.ini

So far I am able to change the last bit through this command :

```sh
cat /etc/network/interfaces | grep -i default | awk -F'.' -vOFS='.' '{$NF=6}1;' > /etc/network/interfaces

```

But the problem is that I still cannot figure out how to replace only the last line of the interfaces file without overwriting the whole content of the file.

Here's how my playbook look like :

```yaml
---
- name: test connectivity
  hosts: all
  tasks:
    - name: ping
      ping:
    - name: change default gateway address
      command: cat /etc/network/interfaces | grep -i default | awk -F'.' -vOFS='.' '{$NF=6}1;' > /etc/network/interfaces 
    - name: restart networking service
      command: systemctl restart networking
    - name: check ip configuration
      command: netstat -rn
...

```

All hint and tips are more than welcome.