We have a file on a managed node and we want to change the line within the file. For example on the remote box this file structure exists.
cd /etc/ansible/playbooks
sudo nano testfile.txt
1.random1
2.random2
3.random3
4.random5
5.random6
So we will create a playbook to modify line 4 which is 4.random5 to changethisline ok.
sudo nano ChangeLineInFile.yml
---
- hosts: webservers
become: true
tasks:
- name: change line in file
lineinfile:
path: /etc/ansible/playbooks/testfile.txt
regexp: '^4.random5'
line: changethisline ok
when: ansible_distribution == 'Ubuntu'
ansible-playbook --ask-become-pass ChangeLineInFile.yml
screen shots below


