# MacOS

*   Grep three lines....

    ```shell
    # highlight `app:`
    kustomize build $BASE | grep -C 3 app:

    # Compare the output directly to see how staging and production differ:
    diff \
      <(kustomize build $OVERLAYS/staging) \
      <(kustomize build $OVERLAYS/production) |\
      more
    ```
*   how to add multiple localhosts to mac, sothat I can run multiple services on same port?

    Add alias IPs for lo0

    ```shell
    sudo ifconfig lo0 alias 127.0.0.2
    sudo ifconfig lo0 alias 127.0.0.3
    ```

    Add hostnames for each of those IPs in `/etc/hosts`

    ```shell
    ##
    # Host Database
    #
    # localhost is used to configure the loopback interface
    # when the system is booting.  Do not change this entry.
    ##
    127.0.0.1       localhost
    255.255.255.255 broadcasthost
    ::1             localhost
    # Added by Sumanth
    127.0.0.1 accountsrv
    127.0.0.2 emailersrv
    127.0.0.3 greetersrv
    # End of section
    # Added by Docker Desktop
    # To allow the same kube context to work on the host and the container:
    127.0.0.1 kubernetes.docker.internal
    # End of section
    ```
*   find process running on a given port

    ```shell
    sudo lsof -i tcp:1668

    lsof -nP +c 15 | grep LISTEN
    ```
*   tree view of filesystem

    ```shell
    tree -d -C -L 2
    ```
