Jul 25, 2026

Linux Shell Scripts: Cron, SysInfo & Disk Monitoring

Bash your head against the keyboard no more! Production-ready Linux shell scripts for task scheduling and system monitoring will automate your troubles away

BLZR

AutomationBashDevOpsLinuxShell Scripting

2076 Words — Reading Time: 9 Minutes, 26 Seconds

24 July 2026, 6:30:00 PM

Task Scheduler Shell Scripts

Here are several Task Scheduler Shell Scripts that help automate various tasks on Linux using cron jobs or a custom scheduling mechanism:

1. Simple Task Scheduler Script (Daily Task)

This script runs a specific task every day at a set time (e.g., 2:00 AM).

#!/bin/bash
# Task Scheduler: Daily Task Example
# Description: This script runs a task (e.g., a backup) daily at 2:00 AM.
TASK_LOG="/var/log/task_scheduler.log"
TASK_COMMAND="tar -czf /backup/my_backup.tar.gz /home/user/data"

log_task() {
    TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
    echo "$TIMESTAMP - Task started" >> "$TASK_LOG"
    $TASK_COMMAND
    echo "$TIMESTAMP - Task completed" >> "$TASK_LOG"
}

log_task

Usage: Schedule the script using cron by adding this to your crontab (crontab -e):

0 2 * * * /path/to/your/script.sh

This will run the script at 2:00 AM every day.

2. Hourly Task Scheduler (Log Cleanup)

This script runs a log cleanup every hour.

#!/bin/bash
# Task Scheduler: Hourly Log Cleanup
# Description: This script removes logs older than 7 days every hour.
LOG_DIR="/var/log"
LOG_FILE="/var/log/cleanup.log"

cleanup_logs() {
    TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
    echo "$TIMESTAMP - Starting log cleanup" >> "$LOG_FILE"
    find $LOG_DIR -type f -name "*.log" -mtime +7 -exec rm {} \;
    echo "$TIMESTAMP - Log cleanup completed" >> "$LOG_FILE"
}

cleanup_logs

Usage: Schedule it to run hourly with the following cron job:

0 * * * * /path/to/your/script.sh

3. Weekly Backup Task Scheduler

This script runs a backup task every Sunday at 3:00 AM.

#!/bin/bash
# Task Scheduler: Weekly Backup Task
# Description: This script performs a backup every Sunday at 3:00 AM.
BACKUP_DIR="/home/user/backups"
SOURCE_DIR="/home/user/data"

perform_backup() {
    tar -czf $BACKUP_DIR/backup_$(date +\%F).tar.gz $SOURCE_DIR
}

perform_backup

Usage: Schedule it in cron to run at 3:00 AM on Sunday:

0 3 * * 0 /path/to/your/script.sh

4. Monthly Disk Space Checker

This script checks disk space usage and sends a report if usage exceeds 90%.

#!/bin/bash
# Task Scheduler: Monthly Disk Space Check
# Description: This script checks disk space usage every month and sends an alert if it's over 90%.
THRESHOLD=90
ALERT_EMAIL="[email protected]"
DISK_USAGE=$(df / | grep / | awk '{ print $5}' | sed 's/%//g')

if [ "$DISK_USAGE" -gt "$THRESHOLD" ]; then
    echo "Disk space is critically high: ${DISK_USAGE}% usage" | mail -s "Disk Space Alert" "$ALERT_EMAIL"
    echo "$(date '+\%Y-\%m-\%d \%H:\%M:\%S') - Disk Space Alert: -${DISK_USAGE}% usage" >> /var/log/disk_space.log
fi

Usage: Schedule it to run monthly:

0 0 1 * * /path/to/your/script.sh

5. Task Scheduler with Custom Interval (Every 15 Minutes)

This script runs a specific task every 15 minutes.

#!/bin/bash
# Task Scheduler: Task Every 15 Minutes
# Description: This script runs a custom task every 15 minutes.
TASK_LOG="/var/log/task_every_15min.log"
TASK_COMMAND="python3 /path/to/script.py"

log_task() {
    TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
    echo "$TIMESTAMP - Task started" >> "$TASK_LOG"
    $TASK_COMMAND
    echo "$TIMESTAMP - Task completed" >> "$TASK_LOG"
}

log_task

Usage: Schedule the script to run every 15 minutes:

*/15 * * * * /path/to/your/script.sh

6. Task Scheduler with Random Time Interval

This script runs a task at a random interval between 1 and 10 minutes.

#!/bin/bash
# Task Scheduler: Random Time Interval
# Description: This script runs a task at a random interval between 1 and 10 minutes.
TASK_LOG="/var/log/random_task.log"
TASK_COMMAND="echo 'Random task executed'" 

run_random_task() {
    TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
    echo "$TIMESTAMP - Task started" >> "$TASK_LOG"
    $TASK_COMMAND
    echo "$TIMESTAMP - Task completed" >> "$TASK_LOG"
}

RANDOM_INTERVAL=$(((RANDOM % 10) + 1)) # Random between 1 and 10 minutes
sleep $((RANDOM_INTERVAL * 60)) # Sleep for random minutes
run_random_task

Usage: You can run this script using a simple cron job that keeps executing it:

* * * * * /path/to/your/script.sh

7. Task Scheduler: System Health Check

This script checks the system’s health and logs any critical issues (CPU, memory, disk usage).

#!/bin/bash
# Task Scheduler: System Health Check
# Description: This script checks the system's CPU, memory, and disk usage, and logs any issues.
HEALTH_LOG="/var/log/system_health.log"

check_system_health() {
    CPU_USAGE=$(top -bn1 | grep "Cpu(s)" | sed 's/.*, *\([0-9.]*\)%* id.*/\1/' | awk '{print 100 - $1}')
    MEM_USAGE=$(free -m | grep Mem | awk '{print $3/$2 * 100.0}')
    DISK_USAGE=$(df / | grep / | awk '{ print $5}' | sed 's/%//g')
    TIMESTAMP=$(date "+%Y-%m-%d %H:%M:%S")
    
    echo "$TIMESTAMP - CPU Usage: $CPU_USAGE\%, Memory Usage:$MEM_USAGE%, Disk Usage: $DISK_USAGE\%" >> "$HEALTH_LOG"
    
    if [ $(echo "$CPU_USAGE > 90" | bc) -eq 1 ]; then
        echo "$TIMESTAMP - CRITICAL: High CPU Usage" >> "$HEALTH_LOG"
    fi
}

These Task Scheduler Shell Scripts automate important system management tasks, from backups to system health checks, ensuring smooth operations with minimal manual intervention. You can use cron jobs to schedule them as per your needs.

System Information Shell Scripts

1. System Information Overview Script

This script provides an overview of your system, including the hostname, OS, kernel version, uptime, and CPU load.

#!/bin/bash
# System Information Overview
echo "System Overview:"
echo "==============="
echo "Hostname: $(hostname)"
echo "OS: $(uname -o)"
echo "Kernel Version: $(uname -r)"
echo "Uptime: $(uptime -p)"
echo "CPU Load: $(uptime | awk -F'load average:' '{ print $2}')"
echo "Disk Usage: $(df -h / | awk 'NR==2 {print $3 "/" $2 " (" $5 " used)"}')"

Usage: This will output the basic system information for a quick overview.

2. CPU Information Script

This script displays detailed information about the CPU, including its model, cores, and clock speed.

#!/bin/bash
# CPU Information
echo "CPU Information:"
echo "================"
lscpu | grep -E 'Model name|CPU(s)|Thread|Core|Socket'
echo "CPU Usage: $(top -bn1 | grep "Cpu(s)" | sed 's/.*, *\([0-9.]*\)%* id.*/\1/' | awk '{print 100 - $1 "%"}')"

Usage: This will provide detailed CPU information and usage.

3. Memory Usage Script

This script shows the total, used, and free memory on the system.

#!/bin/bash
# Memory Usage
echo "Memory Information:"
echo "===================="
free -h | awk 'NR==2 {print "Total: "$2" Used: "$3" Free: "$4 " Buffers/Cache: "$6}'

Usage: This script will display memory usage statistics in a human-readable format.

4. Disk Usage Script

This script checks the disk usage of all mounted filesystems.

#!/bin/bash
# Disk Usage
echo "Disk Usage Information:"
echo "======================="
df -h | grep -vE '^Filesystem|tmpfs|cdrom' # Exclude tmp and cdrom

Usage: This will output disk space usage filesystems, excluding temporary filesystems and CD-ROMs.

5. Network Information Script

This script shows basic network information including IP addresses, netmask, and default gateway.

#!/bin/bash
# Network
echo "Network Information:"
echo "====================="
echo "IP Address: $(hostname -I)"
echo "Netmask: $(ifconfig | grep -w inet | awk '{print $4}')"
echo "Gateway: $(ip route | grep default | awk '{print $3}')"

Usage: This provides basic network configuration and connection details.

6. System Resource Usage Script

This script provides a snapshot of resource usage, including CPU, memory, disk, and swap.

#!/bin/bash
# System Resource Usage
echo "System Resource Usage:"
echo "======================"
echo "CPU Usage: $(top -bn1 | grep "Cpu(s)" | sed 's/.*, *\([0-9.]*\)%* id.*/\1/' | awk '{print 100 - $1 "%"}')"
echo "Memory Usage: $(free -h | grep Mem | awk '{print $3 "/" $2}')"
echo "Disk Usage: $(df -h / | awk 'NR==2 {print $3 "/" $2 " (" $5 " used)"}')"
echo "Swap Usage: $(free -h | grep Swap | awk '{print $3 "/" $2}')"

Usage: This will output the usage of all critical system resources.

7. Uptime & Load Average Script

This script checks the system uptime and load average for the last 1, 5, and 15 minutes.

#!/bin/bash
# System Uptime & Load Average
echo "System Uptime and Load Average:"
echo "==============================="
uptime | awk -F'( |,|:)+' '{ print "Uptime: " $3 " days " $4" hours " $5 " minutes"; print "Load Average: 1 min: "$10" 5 min: "$11" 15 min: "$12}'

Usage: This provides the system uptime and load averages, helping to monitor the system’s health.

8. Top 5 Memory Consuming Processes

This script shows the top 5 processes consuming the most memory.

#!/bin/bash
# Top 5 Memory Consuming Processes
echo "Top 5 Memory Consuming Processes:"
echo "================================="
# Display header and show top 5 memory consuming processes in your system
ps -eo pid,ppid,cmd,%mem,%cpu --sort=-%mem | head -n 6

Disk Space Monitoring Shell Scripts

Here are some Disk Space Monitoring Shell Scripts that can help you track the available space on your system and send alerts when disk usage exceeds a certain threshold.

1. Basic Disk Space Monitoring Script

This script checks the disk space usage and reports if any filesystem exceeds the 90% usage threshold.

#!/bin/bash
# Disk Space Monitoring
# Description: This script checks disk usage and sends an alert if it exceeds 90%.
THRESHOLD=90
ALERT_EMAIL="[email protected]"
DISK_USAGE=$(df / | grep / | awk '{ print $5}' | sed 's/%//g')

if [ "$DISK_USAGE" -gt "$THRESHOLD" ]; then
    echo "Disk space usage is over the threshold! Current usage: ${DISK_USAGE}%" | mail -s "Disk Space Alert" "$ALERT_EMAIL"
    echo "$(date "+%Y-%m-%d %H:%M:%S") - Disk space alert: Usage is ${DISK_USAGE}%" >> /var/log/disk_space_monitor.log
else
    echo "$(date "+%Y-%m-%d %H:%M:%S") - Disk space is under control: Usage is ${DISK_USAGE}%" >> /var/log/disk_space_monitor.log
fi

Usage: Schedule this script using cron to run at regular intervals (e.g., every hour).

0 * * * * /path/to/disk_space_monitor.sh

2. Disk Space Usage Monitoring for All Filesystems

This script checks the usage of all mounted filesystems and sends an email alert if any of them exceed the threshold.

#!/bin/bash
# Disk Space Monitoring for All Filesystems
# Description: This script checks the usage of all filesystems and alerts if any exceed 90%.
THRESHOLD=90
ALERT_EMAIL="[email protected]"

df -h | grep -vE '^Filesystem|tmpfs|cdrom' | while read -r line; do
    FILESYSTEM=$(echo$line | awk '{print $1}')
    USAGE=$(echo$line | awk '{print $5}' | sed 's/%//')
    
    if [ "$USAGE" -gt "$THRESHOLD" ]; then
        echo "Warning: $FILESYSTEM is over${THRESHOLD}% full! Current usage: ${USAGE}\%" \vert{} mail -s "$FILESYSTEM - Disk Space Alert" "$ALERT_EMAIL"
        echo "$(date "+%Y-%m-%d %H:%M:%S") - ALERT: $FILESYSTEM usage is${USAGE}%" >> /var/log/disk_space_monitor.log
    fi
done

Usage: This can be scheduled using cron to run periodically.

0 * * * * /path/to/disk_space_monitor_all.sh

3. Disk Space Usage and Report Script

This script not only checks disk space usage but also generates a report with disk usage details and sends it via email.

#!/bin/bash
# Disk Space Report
# Description: This script generates a disk space report and emails it if any filesystem exceeds 90% usage.
THRESHOLD=90
ALERT_EMAIL="[email protected]"
REPORT_FILE="/tmp/disk_space_report.txt"

# Generate Report
echo "Disk Space Usage Report - $(date)" > $REPORT_FILE
echo "=========================" >> $REPORT_FILE
df -h | grep -vE '^Filesystem|tmpfs|cdrom' >> $REPORT_FILE

# Check for usage over threshold
df -h | grep -vE '^Filesystem|tmpfs|cdrom' | while read -r line; do
    USAGE=$(echo$line | awk '{print $5}' | sed 's/%//g')
    if [ "$USAGE" -gt "$THRESHOLD" ]; then
        echo "ALERT: Disk usage exceeds $THRESHOLD% on $(echo$line | awk '{print $1}') with$USAGE% usage." | mail -s "Disk Space Alert: $(hostname)" "$ALERT_EMAIL"
        echo "$(date "+%Y-%m-%d %H:%M:%S") - ALERT: $(echo$line | awk '{print $1}') usage is${USAGE}%" >> /var/log/disk_space_monitor.log
    fi
done

# Send Report
cat $REPORT_FILE | mail -s "Disk Space Report for $(hostname)" "$ALERT_EMAIL"
rm $REPORT_FILE

Usage: Schedule this script to run daily at midnight to generate daily disk space usage reports.

0 0 * * * /path/to/disk_space_report.sh

4. Disk Space Monitoring with Notification

This script monitors the disk space and sends a notification via notify-send (for desktop environments) if the space exceeds the defined threshold.

#!/bin/bash
# Disk Space Monitoring with Notification
# Description: This script checks disk usage and sends notifications when space exceeds 90%.
THRESHOLD=90
DISK_USAGE=$(df / | grep / | awk '{ print $5}' | sed 's/%//g')

if [ "$DISK_USAGE" -gt "$THRESHOLD" ]; then
    MESSAGE="Warning: Disk space usage is at ${DISK_USAGE}%!"
    notify-send "Disk Space Alert" "$MESSAGE"
    echo "$(date "+\%Y-\%m-\%d \%H:\%M:\%S") - $MESSAGE" >> /var/log/disk_space_monitor.log
fi

Usage: This is suitable for systems with a graphical interface. You can also schedule it using cron.

*/30 * * * * /path/to/disk_space_notify.sh
  1. Disk Space Check with Email Alerts and Log This script checks disk space usage and logs it to a file. If the usage exceeds the threshold, it sends an email alert.
#!/bin/bash
# Disk Space Check and Alert
# Description: This script checks disk space usage, logs it, and alerts if the usage exceeds 90%.
THRESHOLD=90
ALERT_EMAIL="[email protected]"
LOG_FILE="/var/log/disk_space_alert.log"

# Get current disk usage
DISK_USAGE=$(df / | grep / | awk '{print $5}' | sed 's/%//g')

# Check if usage exceeds threshold
if [ "$DISK_USAGE" -gt "$THRESHOLD" ]; then
    echo "$(date "+%Y-%m-%d %H:%M:%S") - Disk space is over $THRESHOLD% used. Current usage: ${DISK_USAGE}\%" >> $LOG_FILE
    echo "Disk space alert: usage is ${DISK_USAGE}%" | mail -s "Disk Space Alert for $(hostname)" "$ALERT_EMAIL"
fi

Usage: Schedule the script to run at regular intervals (e.g., every hour).

0 * * * * /path/to/disk_space_check.sh

These Disk Space Monitoring Shell Scripts can be helpful to track and manage disk usage, ensuring your systems don’t run out of space unexpectedly. You can customize the threshold and alerting mechanisms based on your needs.

See Also