You may have a look into debug – Print statements during execution, Using Variables and Return Values.

Copy---
- hosts: localhost
  become: true
  gather_facts: false

  vars:
    RESULT:
      STDOUT_LINES:
        - "# name admin@shrrah.esquimail.com"
        - "zimbraIsDelegatedAdminAccount: FALSE"
        - ""
        - "# name prueba5@prueba5.com"
        - ""
        - "# name prueba7@prueba7.com"
        - "zimbraIsDelegatedAdminAccount: TRUE"
        - ""
        - "# name prueba9@prueba9.com"

  tasks:

  - name: Show STDOUT_LINES
    debug:
      msg: "{{ RESULT.STDOUT_LINES }}"

resulting into an output only of

CopyTASK [Show STDOUT_LINES] *****************
ok: [localhost] =>
  msg:
  - '# name admin@shrrah.esquimail.com'
  - 'zimbraIsDelegatedAdminAccount: FALSE'
  - ''
  - '# name prueba5@prueba5.com'
  - ''
  - '# name prueba7@prueba7.com'
  - 'zimbraIsDelegatedAdminAccount: TRUE'
  - ''
  - '# name prueba9@prueba9.com'

and if Ansible Callback plugin is configured to YAML instead of JSON.

To get lines containing certain strings only you may Loop over the list based on a Condition

Copy  - name: Show lines with TRUE only
    debug:
      msg: "{{ item }}"
    when: "'TRUE' in item"
    loop: "{{ RESULT.STDOUT_LINES }}"

resulting into an output of

CopyTASK [Show lines with TRUE only] *******************************
ok: [localhost] => (item=zimbraIsDelegatedAdminAccount: TRUE) =>
  msg: 'zimbraIsDelegatedAdminAccount: TRUE'

Further Documenation

• Index of all Callback Plugins

If you like to have the line before included, you could use an approach like

Copy  - name: Show lines with TRUE and line before
    debug:
      msg: "{{ RESULT.STDOUT_LINES[ansible_loop.index0 - 1] }}\n{{ item }}"
    when: "'TRUE' in item"
    loop: "{{ RESULT.STDOUT_LINES }}"
    loop_control:
      extended: true
      label: "{{ ansible_loop.index0 }}"

resulting into an output of

CopyTASK [Show lines with TRUE and line before] *************************************************************************************************************************************
ok: [localhost] => (item=6) =>
  msg: |-
    # name prueba7@prueba7.com
    zimbraIsDelegatedAdminAccount: TRUE

Further Documentation

• Extended loop variables

Since you are using the shell module, you could use also an approach like

Copy- name: DELEGATED ADMIN ACCOUNTS - check, get and send to the file domain.list
  shell: 
    cmd: /opt/zimbra/bin/zmprov -l gaaa -v zimbraIsDelegatedAdminAccount | grep -B 1 TRUE

and gather only result lines which are true an the line before.

Further Q&A

• grep a file, but show several surrounding lines?

Regarding

... send it to the file.txt

you may have a look into

• Ansible - Save registered variable to file
• Ansible: Save registered variables to file
• ...

Well it looks like you are running ansible-playbook with the -v option. So you are seeing more information because you are in verbose mode.

Also, since you are using with_items in your debug task you will see the contents of the current item displayed as that item is processed. You can control what gets displayed for each item by using the loop_control

- debug: msg=" {{ item.stdout_lines }} "
    with_items: " {{ result.results }} "
  loop_control:
    label: '...'

A: The value of command_results.stdout_lines is the YAML list. Nothing happens to the list when you filter it from_yaml. Use command_results.stdout instead

- set_fact:
    needrestart: "{{ command_results.stdout | from_yaml }}"

Details: Given the below file for testing

shell> cat needrestart.txt 
NEEDRESTART-VER: 3.6
NEEDRESTART-KCUR: 5.14.0-362.24.1.el9_3.0.1.x86_64
NEEDRESTART-KEXP: 5.14.0-362.24.1.el9_3.0.1.x86_64
NEEDRESTART-KSTA: 2
NEEDRESTART-UCSTA: 0

Please read it

    - command: cat needrestart.txt
      register: command_results

You can see that next to the YAML list in the attribute stdout_lines

  command_results.stdout_lines:
  - 'NEEDRESTART-VER: 3.6'
  - 'NEEDRESTART-KCUR: 5.14.0-362.24.1.el9_3.0.1.x86_64'
  - 'NEEDRESTART-KEXP: 5.14.0-362.24.1.el9_3.0.1.x86_64'
  - 'NEEDRESTART-KSTA: 2'
  - 'NEEDRESTART-UCSTA: 0'

there is also the YAML text bloc in the attribute stdout

  command_results.stdout: |-
    NEEDRESTART-VER: 3.6
    NEEDRESTART-KCUR: 5.14.0-362.24.1.el9_3.0.1.x86_64
    NEEDRESTART-KEXP: 5.14.0-362.24.1.el9_3.0.1.x86_64
    NEEDRESTART-KSTA: 2
    NEEDRESTART-UCSTA: 0

Now, you can use from_yaml to (quote):

Converts a YAML string representation into an equivalent structured Ansible variable.

For example,

  needrestart: "{{ command_results.stdout | from_yaml }}"

gives what you want

  needrestart:
    NEEDRESTART-KCUR: 5.14.0-362.24.1.el9_3.0.1.x86_64
    NEEDRESTART-KEXP: 5.14.0-362.24.1.el9_3.0.1.x86_64
    NEEDRESTART-KSTA: 2
    NEEDRESTART-UCSTA: 0
    NEEDRESTART-VER: 3.6

  needrestart['NEEDRESTART-VER']: '3.6'

Notes:

• If you have a list only there are more options. You can convert the items to YAML dictionaries and combine them

  n3: "{{ command_results.stdout_lines | map('from_yaml') | combine }}"

gives the same result

  n3:
    NEEDRESTART-KCUR: 5.14.0-362.24.1.el9_3.0.1.x86_64
    NEEDRESTART-KEXP: 5.14.0-362.24.1.el9_3.0.1.x86_64
    NEEDRESTART-KSTA: 2
    NEEDRESTART-UCSTA: 0
    NEEDRESTART-VER: 3.6

  n3['NEEDRESTART-VER']: '3.6'

• The next option is using the function dict on the split items. The below declaration also gives the same result

    n4: "{{ dict(command_results.stdout_lines | map('split', ':')) }}"

• Example of a complete playbook for testing

- hosts: localhost

  vars:

    n1: "{{ command_results.stdout_lines | from_yaml }}"
    n2: "{{ command_results.stdout | from_yaml }}"
    n3: "{{ command_results.stdout_lines | map('from_yaml') | combine }}"
    n4: "{{ dict(command_results.stdout_lines | map('split', ':')) }}"

  tasks:

    - command: cat needrestart.txt
      register: command_results

    - debug:
        var: command_results.stdout_lines
    - debug:
        var: command_results.stdout

    - debug:
        var: n1
    - debug:
        var: n2
    - debug:
        var: n2['NEEDRESTART-VER']
    - debug:
        var: n3
    - debug:
        var: n3['NEEDRESTART-VER']
    - debug:
        var: n4
    - debug:
        var: n4['NEEDRESTART-VER']

I think you can register the result to a variable, then print with debug.

- name: print to stdout
  command: echo "hello"
  register: hello

- debug: msg="{{ hello.stdout }}"

- debug: msg="{{ hello.stderr }}"

        content:  "{{  all_hosts_list.stdout_lines|join('\n')  }}"

aws cli generates JSON output by default, use this advantage:

---
- hosts: localhost
  gather_facts: no
  tasks:
    - shell: aws sqs list-queues --region eu-west-1
      register: sqs_list
    - debug:
        msg: "{{ (sqs_list.stdout | from_json).QueueUrls | last }}"

Output:

PLAY [localhost] **********************************
TASK [command] ************************************
changed: [localhost]

TASK [debug] **************************************
ok: [localhost] => {
    "msg": "https://eu-west-1.queue.amazonaws.com/xxxxx/test"
}

Something is wrong in your playbook together with the given output. When I build a similar playbook without all the dependencies:

- name: "Check if the deployments defined in group_vars are already installed"
  shell: "{{ item }}"
  register: check_deployments
  loop:
    - "pwd"
    - "ls -al"
    - "pwd"

- name: "Show list of deployments"
  debug:
    var: check_deployments.stdout_lines

I'm getting the information

TASK [Show list of deployments] *************************************************
ok: [localhost] => 
  check_deployments.stdout_lines: VARIABLE IS NOT DEFINED!

This is true, because you loop over a Ansible module and register ALL output into ONE variable. In that case, the variable contains a list of results. So - your loop with check_deployments.stdout_lines is wrong. You need to loop over all check_deployments.results which contains the correct "registered" variable per module run, which you want to check

- name: "Undeploy..."
  debug:
    msg: "stdout: {{ item.cmd }}"
  when: "item.stdout_lines | length > 1"
  loop: "{{ check_deployments.results }}"

This will only output one entry (ls -al). All other will be skipped.

Regarding the comments "You need to register the output of the command in order for Ansible to store it." and "I tried register before, but I cannot find a way to use the register variable in the shell of other play." you may have look into the following minimal example playbook

---
- hosts: localhost
  become: true
  gather_facts: false

  tasks:

  - name: 4. Verify key generation
    shell:
      cmd: "gpg --list-secret-keys --keyid-format=long | sed '4!d' | tr -d ' '"
    register: VAR

  - name: 6. Echo GPG ID
    shell:
      cmd: "echo {{ VAR.stdout_lines }}"
    register: result

  - name: Show result
    debug:
      var: result

or a more generic

---
- hosts: localhost
  become: false
  gather_facts: false

  tasks:

  - name: Echo example 1
    shell:
      cmd: "echo 12:34:56:78:90:AB:CD:EF"
    register: VAR

  - name: Echo example 2
    shell:
      cmd: "echo {{ VAR.stdout_lines }}"
    register: result

  - name: Show registered variable
    debug:
      var: result

  - name: Show result content only
    debug:
      msg: "{{ result }}"

as it shows you how to get familiar with registering, return values and data structures.

Further Documenation

• Registering variables
• Common Return Values
• shell Return Values
• debug module – Print statements during execution

Is there a way to do so without creating a particular playbook with debug or any other modules just by adding an option or piping the output to a grep?

I'm quite sure my above proposition in comment fulfills your expectation. The only requirement is to have a tool installed on the controller to parse json so that you can pipe Ansible output result in your shell.

For the below example, I use jq which is widely used and available in most Linux distribution repos.

The trick here is to:

1. enable loading callbacks for ad-hoc commands.
2. change the stdout callback plugin to use json for ad-hoc commands.

Since you seem to look for a one liner and non "destructive" solution, I used environment variables set directly on the same command line.

Long story short, typing in your shell:

CopyANSIBLE_LOAD_CALLBACK_PLUGINS=1 \
ANSIBLE_STDOUT_CALLBACK=json \
ansible localhost -a "echo toto" | jq -r ".plays[].tasks[].hosts[].stdout"

gives

toto

I think there are a few ways you could handle this.

1) Grep the output before it gets to Ansible:

# Note the change of 'command' to 'shell'
- name: Change the Security Realm to CustomRealm from ManagementRealm
  shell: /jboss-as-7.1.1.Final/bin/jboss-cli.sh --connect--command="/core-service=management/management-interface=http-interface:read-attribute(name=security-realm)" | grep -o 'result.*'
  register: Realm

2) If the output from the source script is always 4 lines long, you can just grab the 3rd line:

# List indexes start at 0
- debug:
  msg: "{{ Realm.stdout_lines[2] | regex_replace('^ *(.*$)', '\\1') }}"

3) The nicest way if you have an option to modify jboss-cli.sh, would be to get the jboss-cli.sh to output valid JSON which can then be parsed by Ansible:

# Assuming jboss-cli.sh produces {"outcome": "success", "result": "ManagementRealm"}
- set_fact:
    jboss_data: "{{ Realm.stdout | from_json }}"
- debug:
    var: jboss_data.result