daemon_monitor

🧿 Daemon Process Monitor

A lightweight C-based Linux daemon that runs in the background, logs its process ID every 2 seconds, and clears the log every 60 seconds (30 cycles). It's a foundational template for building real system daemons.

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📌 Real-World Application

This daemon acts as a process logger, useful in scenarios like:

• Embedded Linux systems where you need low-level process monitoring.
• IoT devices that require simple health tracking of software modules.
• Security: Use this base to monitor processes or detect unexpected changes.
• Custom daemons: Extend this to log system metrics (CPU, RAM, etc.) or integrate with syslog.

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⚙️ Features

• Logs PID every 2 seconds to a file.
• Auto-clears log every 30 writes (~60 seconds).
• Parent exits; child runs in background (true daemon).
• Uses Linux system calls: fork(), open(), write(), sleep().
• Designed for expansion into full-featured system services.

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🗂️ Project Structure

Daemon_monitor/ ├── main.c # Daemon setup and process detachment ├── sl_daemon.c # Logging logic ├── sl_daemon.h # Header for daemon function ├── Makefile # Build system └── README.md # Documentation (this file)

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🧪 How It Works

1. Forks the process: parent exits, child continues.
2. Child closes all file descriptors and becomes a background process.
3. Every 2 seconds, logs the current PID to /home/moni/love.c.
4. After 30 logs, the file is truncated (cleared), and the cycle restarts.

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🛠️ Build Instructions

Prerequisites

• GCC
• Linux OS (Ubuntu/Debian/CentOS/Yocto-compatible)
• Basic command-line experience

Build

make
./daemon_monitor
cat /home/moni/love.c
Hello...I am Monish and my roll number is: 12345
Hello...I am Monish and my roll number is: 12345
...