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Today, in this article, we wear you how to use watch command in linux. Occasionally, we can track changes in the output using the Linux clock. It is advantageous to reflect the current state of events in an operating system in real time. By default it runs the program every two seconds, but using the -n or -interval arguments a different frame can be specified.
When combined with different pipeline instructions, Watch also allows users to maintain control over adding and deleting files. When you press CTRL+C, Watch will pause the terminal while running simultaneously. Linux observation can also be useful when you need to continually monitor script output or troubleshoot a problem. All Linux distributions provide the watch command by default, along with a number of features. We have mentioned below the steps to use watch command in Linux.
Steps to use watch command on Linux
Run command every 2 seconds
Step 1: By default, the watch command is executed after every 2 seconds and shows the output on the terminal. It continues to work until stopped by the user. The watch command uses the following syntax:
watch
Step 2: Whereoption> are the parameters that we will discuss later in this article andcommand> is another command you want to run by the watch utility.
watch date
Execute command every N seconds
Step 1: The Watch command update interval can be overridden. means you can change refresh interval of 2 seconds to the desired interval as well. Syntax:
watch -n
Step 2: Whereinterval in seconds> is the update interval in seconds andcommand> is another command you want to run by the watch utility.
watch -n 5 date
Highlighting the differences between updates
Step 1: You can also highlight the differences between the previous output and the current output. So instead of reading all output, you can keep an eye on the changes. Syntax:
watch -d
Step 2: However, if the interval between updates is too short, it will be a challenge to review the differences, so you should set a reasonable refresh interval.
watch -n 5 -d date
Hide header in output
Step 1: The output of the Watch command shows a header containing time range, command, system nameand system date. However, if you don’t want to see that part, you can also hide it. Syntax:
watch -t
watch -t date
Error beep
Step 1: The watch command can also beep if an update fails. For this to happen, it may first be necessary to verify that the beeper packet is installed or not. If not installed, you can install it using the following command:
sudo apt install beep
Step 2: Syntax:
watch -b date
exit in change
Step 1: By default, the watch command continues to run until manually stopped by the user. However, you can do it exit identify a change in output also. Syntax:
watch -g
watch -n 10 -g data
Step 2: This returns a certain status which can be obtained using the command below:
echo $?
Using big commands
Step 1: You can use other commands with the watch command more cleanly. There are several ways to do this. You may use sign after the watch command and its options.
watch -n 10 -d
Step 2: You can also write you complete custom command also enclosed in single quotes.
watch
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Final Words
We hope you like our article about how to use watch command on Linux. One of the most popular Linux commands among power users is watch, which allows them to run a specific command regularly and show the output in a console or terminal window. With the watch command, you can run commands repeatedly until you stop them or until you encounter a circumstance that automatically ends the loop. When you need to wait for something to change before moving on to the next job, this can be very helpful.