====== Use Watch for repetitive command line actions ======
<color darkorange>Apr 2021</color>
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==== Overview ====

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When you perform an action from the command line, it gets executed just once. So if you type <color #ed1c24>Date</color>, you will see the current time and date at the execution time of the command. But sometimes it is very useful if you are looking for a change to have your command line executed many times, and this can be achieved with a command called <color #ed1c24>Watch</color>.
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==== Using Watch ====
Using <color #ed1c24>Watch</color> is very simple, but first lets look at a simple command line example.
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Lets say I want to see some PODs coming up in Kubernetes, I have to use the following command:
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    kubectl -n mediakind get pods |grep stream-processor
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And as an example, this will give me a single output like so.
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<file>
mux-bckp-1-stream-processor-mux-65c46756b5-4kvcz               3/5     Running
mux-main-1-stream-processor-mux-7879d98786-nkphj               2/5     Running
stream-processor-config-656fd6d7f4-4wvw4                       1/1     Running
stream-processor-simulcrypt-bckp-6d5c94954d-7kp52              1/3     Running
stream-processor-simulcrypt-main-6f8bd6845b-8lc6g              3/3     Running
stream-processor-statmux-bckp-75dc49984-sc9ft                  1/3     Running
stream-processor-statmux-main-6d9659dbc6-8nhfv                 3/3     Running
stream-processor-ui-connector-789b688bc5-fg6x7                 1/1     Running
</file>
I can see some of my PODs are up, but not all of them, so I have to keep running this command over and over. Watch will do this for me, and to do this I can put my original command in quotes, and use Watch at the start.
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    watch "kubectl -n mediakind get pods |grep stream-processor"
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Now I will see something similar to the following, and it will automatically refresh every 2 seconds.
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<file>
Every 2.0s: kubectl -n mediakind get pods |grep stream-processor                        Wed Apr 21 17:40:43 2021

mux-bckp-1-stream-processor-mux-65c46756b5-4kvcz               5/5     Running
mux-main-1-stream-processor-mux-7879d98786-nkphj               5/5     Running
stream-processor-config-656fd6d7f4-4wvw4                       1/1     Running
stream-processor-simulcrypt-bckp-6d5c94954d-7kp52              3/3     Running
stream-processor-simulcrypt-main-6f8bd6845b-8lc6g              3/3     Running
stream-processor-statmux-bckp-75dc49984-sc9ft                  3/3     Running
stream-processor-statmux-main-6d9659dbc6-8nhfv                 3/3     Running
stream-processor-ui-connector-789b688bc5-fg6x7                 1/1     Running
</file>
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Use <color #ed1c24>CTRL-C</color> to exit <color #ed1c24>Watch</color>.
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