Shell scripts are a powerful tool for automating tasks on a computer system. They allow users to run a series of commands and perform complex operations with ease. One such task that can be automated with a shell script is getting the CPU usage of a system. In this article, we will discuss how to write a shell script to get CPU usage and monitor the performance of your system.
To begin with, let's understand what CPU usage is. CPU usage refers to the percentage of time that the central processing unit (CPU) is busy executing instructions. It is a crucial metric that helps in monitoring the performance of a system. A high CPU usage can indicate a bottleneck in the system, which can lead to slow performance and even system crashes.
Now, let's dive into the steps to create a shell script to get CPU usage.
Step 1: Open a text editor
The first step is to open a text editor such as Notepad, Sublime Text, or Vim. This is where we will write our shell script.
Step 2: Define the shebang
The shebang is the first line of a shell script and is used to specify the interpreter that will be used to execute the script. In this case, we will use the bash interpreter, so our shebang will be #!/bin/bash.
Step 3: Create variables
Next, we will create variables to store the CPU usage values. We will use the 'top' command to get the CPU usage and store it in a variable named 'cpu_usage'. We will also create a variable named 'timestamp' to store the current date and time.
Step 4: Use a loop
To continuously monitor the CPU usage, we will use a loop. The 'while' loop will run indefinitely until we stop the script. Inside the loop, we will use the 'top' command to get the CPU usage and store it in the 'cpu_usage' variable. We will also use the 'date' command to get the current date and time and store it in the 'timestamp' variable.
Step 5: Print the results
Finally, we will print the results to the console. We will use the 'echo' command to display the CPU usage and the timestamp. We can also use the 'sleep' command to set a delay between each iteration of the loop.
Step 6: Save the script
Once we have written the script, we need to save it with a .sh extension. For example, cpu_usage.sh.
Step 7: Make the script executable
Before we can run the script, we need to make it executable. We can do this by using the 'chmod' command followed by the +x option and the name of the script. In this case, it will be chmod +x cpu_usage.sh.
Step 8: Run the script
To run the script, we simply need to type ./cpu_usage.sh in the terminal. This will start the script, and we will be able to see the CPU usage and the timestamp printed to the console.
Congratulations, you have successfully created a shell script to get CPU usage. You can now use this script to monitor the performance of your system regularly. You can also modify the script to send alerts if the CPU usage goes above a certain threshold or to log the results to a file.
In conclusion, shell scripts are a powerful tool that can help automate tasks and improve the efficiency of a system. The script we created to get CPU usage is just one example of the many tasks that can be automated with shell scripting. With some basic knowledge of shell scripting, users can create customized scripts to suit their specific needs and make their computing experience even more efficient.
