☑️Day 12: Advance Shell Scripting

🔹Table Of content :

• ✅Introduction

• ✅Key Learnings and Concepts

  • ✅Monitoring System Resources with Commands

  • ✅Using awk for Data Processing

  • ✅The while Loop in Action

  • ✅cut Command for Precise Data Extraction

  • ✅Advanced vim Commands

• ✅Disk Usage Check Script

• ✅Takeaways from Day 12

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Hey DevOps Enthusiasts,

Welcome to Day 12 🚀!

Today, I stepped into the world of system monitoring using advanced shell scripting techniques. From tracking memory usage to writing a script for disk checks, these skills are crucial for ensuring smooth system operations.

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✅Key Learnings and Concepts

✅1. Monitoring System Resources with Commands

I explored several essential commands for monitoring system resources, which are key for keeping an eye on the health of a server:

• free: Displays information about RAM usage, helping to keep tabs on memory consumption.

• df -H: Shows the disk usage in human-readable form, providing insight into how much space is left on various filesystems.

• top: A real-time display of CPU usage, processes, and memory, useful for identifying high-resource processes.

✅2. Using awk for Data Processing

The awk command is incredibly useful for separating columns from command output. I used it to extract the filesystem and disk usage columns from the df -H output:

df -H | awk '{print $5 " " $1}'

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✅3. The while Loop in Action

Loops are essential when automating repetitive tasks. Today, I used a while loop to iterate over disk usage data and check for critical levels.

while [ condition ];
do
    # statements
    # commands
done

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✅4. cut Command for Precise Data Extraction

To isolate the percentage of disk space used, I used the cut command to extract the numerical part of the disk usage:

usage=$(echo $output | awk '{print $1}' | cut -d'%' -f1)

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✅5. Advanced vim Commands

Mastering the text editor vim is key for efficiently managing and editing scripts. Here are some commands I practiced:

• :wq: Save and quit.

• i: Enter insert mode.

• dd: Delete a line.

• u: Undo the last change.

These shortcuts will save a lot of time when working in the terminal.

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✅Disk Usage Check Script

As part of my learning, I wrote a script that checks disk usage and alerts if any filesystem exceeds 90% usage. Here’s the code:

#!/bin/bash

df -H | awk '{print $5 " " $1}' | while read output;
do
  echo "Disk Detail: $output"
  usage=$(echo $output | awk '{print $1}' | cut -d'%' -f1)
  file_sys=$(echo $output | awk '{print $2}')

  if [ $usage -ge 90 ]; then
    echo "CRITICAL for $file_sys"
  fi
done

This script loops through the disk usage data, checks each filesystem's percentage used, and flags any critical thresholds.

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✅Takeaways from Day 12

• System Monitoring: Knowing how to track memory, CPU, and disk usage is essential for server health.

• Scripting for Automation: Using commands like awk, cut, and loops, I can now automate resource checks, improving efficiency.

• Mastering vim: Learning the basics of vim commands has made editing scripts faster and more productive.

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🚀Stay tuned for more updates on my DevOps journey! 📅

Feel free to reach out to me if you have any questions or need any more help. Let’s connect, learn, and succeed together!

Thanks for joining me on Day 12 of this exciting journey. Let’s keep leveling up our skills!

Happy Learning!😊

#90DaysOfDevOps

#Linux #ShellScripting #SystemMonitoring #Automation #DevOpsJourney #TaskAutomation #BashScripting