请求开发轻量Linux脚本：监控日志变更并触发邮件通知

Got it, let's put together a lightweight, reliable solution for your Raspberry Pi 2 running Raspbian/Debian Stretch. This will monitor your GPIO daemon's log file and fire off an email whenever new content is added—no need to include the log lines since you know they're a fixed 24-line repeat.

Step 1: Install Required Tools #

First, we'll need two packages: inotify-tools (for efficient file change monitoring, way lighter than polling with tail -f) and mailutils (for sending emails). Run this command to install them:

sudo apt update && sudo apt install -y inotify-tools mailutils

Step 2: Create the Monitoring Script #

Make a new script file (let's call it gpio_log_monitor.sh) with the following content. Be sure to replace the placeholders with your actual log path and email recipient:

#!/bin/bash

# Configuration - update these values!
LOG_FILE="/home/pi/gpio_daemon.log"  # Path to your GPIO script's log
EMAIL_TO="your-alert-email@example.com"  # Email to send notifications to
COOLDOWN=60  # Seconds to wait before sending another alert (prevents spam from 24-line writes)

# Track when we last sent an email
last_alert_time=0

echo "Starting GPIO log monitor... Watching $LOG_FILE"

# Monitor the log file for modifications
while inotifywait -e modify "$LOG_FILE"; do
    current_time=$(date +%s)
    
    # Only send an alert if we're outside the cooldown window
    if (( current_time - last_alert_time > COOLDOWN )); then
        # Send a simple alert email
        echo "GPIO daemon log has new entries" | mail -s "GPIO Log Update Alert" "$EMAIL_TO"
        
        # Update the last alert time
        last_alert_time=$current_time
        echo "[$(date '+%Y-%m-%d %H:%M:%S')] Sent alert email to $EMAIL_TO"
    else
        echo "[$(date '+%Y-%m-%d %H:%M:%S')] Skipping alert - cooldown active"
    fi
done

Step 3: Configure Email Delivery (If Needed) #

If your Pi can't send emails out of the box (common with home setups), configure ssmtp to use an external email provider like Gmail (note: you'll need an app password if using 2FA on your Google account):

1. Install ssmtp:

sudo apt install -y ssmtp

2. Edit the ssmtp config file:

sudo nano /etc/ssmtp/ssmtp.conf

Replace the contents with this (adjust for your email provider):

root=your-email@gmail.com
mailhub=smtp.gmail.com:587
AuthUser=your-email@gmail.com
AuthPass=your-google-app-password
UseTLS=YES
UseSTARTTLS=YES
FromLineOverride=YES

3. Tell mailutils to use ssmtp:

sudo nano /etc/mail.rc

Add this line at the end:

set sendmail="/usr/sbin/ssmtp -t"

Step 4: Make the Script Run Automatically #

1. Give the script execute permissions:

chmod +x gpio_log_monitor.sh

2. Test it out first to make sure it works:

./gpio_log_monitor.sh &

3. To make it start on boot, edit /etc/rc.local:

sudo nano /etc/rc.local

Add this line right before exit 0 (replace the path with where your script is saved):

/home/pi/gpio_log_monitor.sh &

Quick Notes #

• Permissions: Make sure the script has read access to your log file (most logs are readable by all users, but double-check if you've set custom permissions).
• Cooldown Adjustment: The 60-second cooldown prevents multiple alerts from firing as the 24 lines are written. You can tweak this value if needed.
• Check Status: Use ps aux | grep gpio_log_monitor.sh to verify the script is running in the background.

内容的提问来源于stack exchange，提问作者Richarleson Takahashi Neto