Stop Wasting Time: Use These 6 Linux Shell Scripting to Supercharge Your Workflow

Today, we will explain why Linux shell scripting is an important tool for DevOps professionals. For many years, shell scripting has been used as an important tool in the Linux environment.

If there is Linux, we will need Linux shell scripting. Shell scripting is also important for DevOps professionals because it enables us to automate daily tasks on Linux servers or machines.

There are many tasks that we can automate with the help of Linux shell scripting, saving us time that can be used for other work. For a DevOps professional, whether it is from the infrastructure side or the application side, shell scripting is very important.

Today, through this blog, we are going to tell you about the best online shell script compilers, bash/shell tutorials, and some basic shell scripts that are essential for a DevOps professional. For example, what is fi in a shell script?

What is a Linux Shell script?

Linux Shell scripting is a way by which you can automate any task. You just must keep in mind some Linux commands and put them in a file, and save the file with the name .sh, like myshellscript.sh. These scripts can maintain your server/system, install or remove software, backup files, and even clean up all the logs or RAM from the server by monitoring your service’s disk or RAM. Bash (Bourne Again Shell) is the most used shell for scripting in Linux.

Best online bash/shell script compilers

The best thing about learning or practicing shell scripting is that now you don’t even need a Linux machine or server for it. There are many online compilers available in the market on which you can practice and run shell/bash scripting from your browser itself.

• Jdoodle bash compiler
• Replit bash compiler
• Online gdb bash compiler

Above, we have provided some of the best online bash/shell compilers. You don’t need to set up your local Linux environment.

Learn Linux commands

• ls – Lists files and directories in the current directory.
• pwd – Prints the current working directory.
• rm – Removes files or directories.
• touch – Creates an empty file or updates the timestamp of a file.
• cp – Copies files or directories.
• mv – Moves or renames files and directories.
• grep – Searches for a pattern in a file or input stream.
• mkdir – Creates a new directory.
• cd – Changes the current directory.
• cat – Displays the content of files.
• zip – Compresses files into a zip archive.
• unzip – Extracts files from a zip archive.
• tar – Archives files and directories into a single file (often with compression).
• vim – Opens a file in the Vim text editor.
• sed – Stream editor for filtering and transforming text.
• head – Displays the first few lines of a file.
• tail – Displays the last few lines of a file.
• diff – Compares two files line by line.
• locate – Quickly finds file paths by searching a prebuilt index.
• find – Searches for files and directories in real-time based on conditions.
• sudo – Executes a command with superuser privileges.
• chmod – Changes file or directory permissions.
• chown – Changes ownership of a file or directory.
• ps – Lists running processes.
• useradd – Adds a new user account.
• passwd – Changes a user’s password.
• userdel – Deletes a user account.
• df – Shows disk space usage of file systems.
• du – Displays disk usage of files and directories.
• top – Monitors system processes and resource usage in real-time.
• uptime – Displays how long the system has been running.
• hostname – Shows or sets the system’s hostname.
• date – Displays or sets the current date and time.
• systemctl – Manages systemd services.
• kill – Sends a signal (usually terminate) to a process.
• ping – Checks connectivity to a host using ICMP echo requests.
• wget – Downloads files from the web via HTTP or FTP.
• curl – Transfers data to or from a server using various protocols.
• scp – Securely copies files between systems over SSH.
• sync – Efficiently syncs files and directories between locations.
• ip – Shows/manages IP addresses, routes, and network interfaces.
• netstat – Displays network connections and listening ports.
• traceroute – Traces the path packets take to a network host.
• nslookup – Queries DNS records for a domain.
• dig – Performs detailed DNS lookups.
• history – Shows previously executed commands in the shell.

Discover why mastering Linux is essential for every NOC and DevOps engineer in 2025. Learn the skills, tools, and commands that matter the most.

Basic shell script for your practice

The more you practice shell scripting, the more you will understand scripting, and it will be easy to apply logic. We can start with basic scripts as well. The good part is that these scripts are very commonly used in a production environment.

• Write a shell script that checks if the disk space usage on the server exceeds 75%. If it does, the script should send an email alert.

#!/bin/bash

# Set threshold (in percentage)
THRESHOLD=75

# Set email details
EMAIL="you@example.com"
SUBJECT="Disk Space Alert on $(hostname)"
BODY="/tmp/disk_alert.txt"

# Get disk usage for root '/'
USAGE=$(df -h / | awk 'NR==2 {print $5}' | sed 's/%//')

if [ "$USAGE" -ge "$THRESHOLD" ]; then
    echo "Disk usage on $(hostname) has reached $USAGE%." > $BODY
    echo "Please check the disk space immediately." >> $BODY
    mail -s "$SUBJECT" "$EMAIL" < $BODY
fi

• If the server’s RAM or swap memory is full, how can we automatically clear it using a script?

#!/bin/bash

# Thresholds (in percentage)
RAM_THRESHOLD=80
SWAP_THRESHOLD=80

# Email Alert Setup
EMAIL="you@example.com"
SUBJECT="Memory Alert on $(hostname)"
BODY="/tmp/mem_alert.txt"

# Get RAM and SWAP usage
RAM_USAGE=$(free | awk '/Mem:/ { printf("%.0f"), $3/$2 * 100 }')
SWAP_USAGE=$(free | awk '/Swap:/ { if ($2 > 0) printf("%.0f"), $3/$2 * 100; else print 0 }')

# Clear cache function
clear_ram() {
    echo "Clearing RAM cache..."
    sync; echo 3 > /proc/sys/vm/drop_caches
}

# Clear swap function
clear_swap() {
    echo "Clearing swap memory..."
    swapoff -a && swapon -a
}

# Main Logic
if [ "$RAM_USAGE" -ge "$RAM_THRESHOLD" ]; then
    echo "RAM usage is at ${RAM_USAGE}%. Clearing cache." > $BODY
    clear_ram
    mail -s "$SUBJECT - RAM Cleared" "$EMAIL" < $BODY
fi

if [ "$SWAP_USAGE" -ge "$SWAP_THRESHOLD" ]; then
    echo "SWAP usage is at ${SWAP_USAGE}%. Clearing swap." > $BODY
    clear_swap
    mail -s "$SUBJECT - Swap Cleared" "$EMAIL" < $BODY
fi

• We want to monitor a specific Java process on a server. If the process goes down or stops running for any reason, the server should automatically send us an email alert notifying us of the issue.

#!/bin/bash

# Define the process keyword (adjust this to match your Java process name or main class)
PROCESS_KEYWORD="MyJavaApp"

# Email settings
EMAIL="you@example.com"
SUBJECT="ALERT: Java Process Down on $(hostname)"
BODY="/tmp/java_process_alert.txt"

# Check if the process is running
if ! pgrep -f "$PROCESS_KEYWORD" > /dev/null; then
    echo "The Java process with keyword '$PROCESS_KEYWORD' is not running on $(hostname)." > "$BODY"
    echo "Please check the server immediately." >> "$BODY"
    mail -s "$SUBJECT" "$EMAIL" < "$BODY"
fi

• How can we create a shell script to take a backup of the server automatically?

#!/bin/bash

# Directories to back up
SOURCE_DIRS="/var/www /etc"

# Backup destination
BACKUP_DIR="/backups"
DATE=$(date +%F-%H%M)
HOSTNAME=$(hostname)
BACKUP_FILE="$BACKUP_DIR/${HOSTNAME}-backup-$DATE.tar.gz"

# Log file
LOG_FILE="/var/log/server_backup.log"

# Create backup directory if it doesn't exist
mkdir -p "$BACKUP_DIR"

# Perform the backup
echo "[$(date)] Starting backup..." >> "$LOG_FILE"
tar -czf "$BACKUP_FILE" $SOURCE_DIRS 2>> "$LOG_FILE"

if [ $? -eq 0 ]; then
    echo "[$(date)] Backup successful: $BACKUP_FILE" >> "$LOG_FILE"
else
    echo "[$(date)] Backup FAILED" >> "$LOG_FILE"
fi

• If the server load reaches or exceeds 70%, we want to be notified by email.

#!/bin/bash

# Load threshold (adjust as needed)
THRESHOLD=0.70

# Email details
EMAIL="you@example.com"
SUBJECT="ALERT: High Server Load on $(hostname)"
BODY="/tmp/server_load_alert.txt"

# Get 1-minute average load
LOAD=$(uptime | awk -F 'load average:' '{ print $2 }' | cut -d',' -f1 | sed 's/ //g')

# Convert load to floating point comparison
if (( $(echo "$LOAD >= $THRESHOLD" | bc -l) )); then
    echo "High server load detected on $(hostname)" > $BODY
    echo "Current load is: $LOAD" >> $BODY
    echo "Threshold is: $THRESHOLD" >> $BODY
    mail -s "$SUBJECT" "$EMAIL" < $BODY
fi

One of the most asked questions by beginners is

What is fi in Shell Script?

In bash scripting, fi is used to close a if statement. Think of it as the reverse of if. You start a condition with the if keyword and end it with the fi keyword.

For example: 

num=15
if [ $num -gt 10 ]; then
  echo "Number is greater than 10"
fi

Output: 
Number is greater than 10

What is a for loop in a Linux shell scripting?

A for loop is used to iterate over a list of items and execute a block of code for each item. It’s useful for automating repetitive tasks.
Suppose you have a list of items, and you want to do some work on those items, then we can get our work done using the for loop. The for loop will keep working as long as the condition is true; as soon as the condition becomes false, the loop will stop doing its work.

Example:

for i in {1..5}
do
   echo "Number: $i"
done

Output:
Number: 1
Number: 2
Number: 3
Number: 4
Number: 5

Conclusion

In summary, Linux shell scripting is a powerful tool in Linux that helps automate many tasks with ease. We explored how different types of shell scripts can be useful in real-world production environments. We also covered essential concepts like using online shell script compilers, if conditions, and for loops. By using shell scripts, you not only simplify your daily tasks but also save valuable time that can be used on other important work, ultimately boosting your productivity.

FAQs