Daemon Mode

🔄 Daemon Mode

Comprehensive guide for automatic folder monitoring and batch processing.

🎯 Overview

Daemon Mode is designed for:

• ✅ Automatic file processing - Convert files as they appear
• ✅ Continuous operation - Run in background
• ✅ Batch processing - Handle multiple files
• ✅ Server deployment - Enterprise environments
• ✅ Production workflows - Automated label generation

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🚀 Getting Started

Start Daemon

# Basic start (default folder)
ZPL2PDF.exe start

# Custom folder and dimensions
ZPL2PDF.exe start -l "C:\WatchFolder" -w 7.5 -h 15 -u in

# High resolution processing
ZPL2PDF.exe start -l "./watch" -w 100 -h 200 -u mm -d 300

Check Status

# Check if daemon is running
ZPL2PDF.exe status

# Expected output:
# Daemon is running (PID: 1234)
# Monitoring folder: C:\WatchFolder
# Processing files: 0

Stop Daemon

# Graceful shutdown
ZPL2PDF.exe stop

# Expected output:
# Stopping daemon...
# Daemon stopped successfully

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📁 Folder Configuration

Default Folders

Platform	Default Watch Folder
Windows	%USERPROFILE%\Documents\ZPL2PDF Auto Converter
Linux	$HOME/Documents/ZPL2PDF Auto Converter
macOS	$HOME/Documents/ZPL2PDF Auto Converter

Custom Folder Setup

# Create custom watch folder
mkdir "C:\MyLabelProcessing"

# Start daemon with custom folder
ZPL2PDF.exe start -l "C:\MyLabelProcessing" -w 7.5 -h 15 -u in

Folder Structure

WatchFolder/
├── input/          ← Place ZPL files here
├── processing/     ← Files being processed
├── output/         ← Generated PDFs
└── error/          ← Failed conversions

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⚙️ Configuration Options

Dimension Settings

# Fixed dimensions for all files
ZPL2PDF.exe start -l "./watch" -w 10 -h 15 -u cm

# High resolution processing
ZPL2PDF.exe start -l "./watch" -w 7.5 -h 15 -u in -d 300

# Mixed units (width in cm, height in mm)
ZPL2PDF.exe start -l "./watch" -w 10 -h 150 -u cm  # Height converted to cm

Processing Options

# Standard processing
ZPL2PDF.exe start -l "./watch"

# High quality processing
ZPL2PDF.exe start -l "./watch" -d 300

# Fast processing (lower quality)
ZPL2PDF.exe start -l "./watch" -d 150

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🔄 File Processing Workflow

1. File Detection

• Daemon monitors the watch folder
• Detects new .txt and .prn files
• Validates file format and accessibility

2. Queue Processing

• Files are added to processing queue
• Sequential processing to avoid conflicts
• Retry mechanism for locked files

3. Conversion Process

• Extract dimensions from ZPL (if available)
• Apply fixed dimensions (if specified)
• Generate PDF with specified quality
• Save to output folder

4. Cleanup

• Remove processed files (optional)
• Log processing results
• Handle errors gracefully

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📊 Monitoring and Logging

Real-time Monitoring

# Check daemon status
ZPL2PDF.exe status

# Detailed status information:
# - Process ID (PID)
# - Watch folder path
# - Files in queue
# - Processing statistics
# - Last activity time

Log Files

%TEMP%/zpl2pdf.log          # Windows
/tmp/zpl2pdf.log            # Linux/macOS

Log Levels

• Info: General processing information
• Warning: Non-critical issues
• Error: Processing failures
• Debug: Detailed debugging information

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🏢 Enterprise Features

PID Management

# Check if daemon is running by PID
ZPL2PDF.exe status

# Output: Daemon is running (PID: 1234)
# Use PID to monitor process externally

Process Monitoring

# Windows - Check if process exists
tasklist /FI "PID eq 1234"

# Linux - Check if process exists  
ps -p 1234

# Kill daemon if unresponsive
ZPL2PDF.exe stop  # Graceful shutdown
# or
kill 1234         # Force kill (Linux)
taskkill /PID 1234 /F  # Force kill (Windows)

Service Integration

# Run as Windows Service (using NSSM)
nssm install ZPL2PDF "C:\Program Files\ZPL2PDF\ZPL2PDF.exe" start -l "C:\WatchFolder"

# Run as systemd service (Linux)
sudo systemctl enable zpl2pdf-daemon
sudo systemctl start zpl2pdf-daemon

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🔧 Advanced Configuration

Environment Variables

# Set default language
export ZPL2PDF_LANGUAGE=pt-BR

# Set default watch folder
export ZPL2PDF_WATCH_FOLDER="/var/zpl2pdf/watch"

# Set log level
export ZPL2PDF_LOG_LEVEL=Debug

Configuration File

Create zpl2pdf.json:

{
  "defaultWatchFolder": "C:\\WatchFolder",
  "labelWidth": 7.5,
  "labelHeight": 15,
  "unit": "in",
  "dpi": 203,
  "logLevel": "Info",
  "retryDelay": 2000,
  "maxRetries": 3
}

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🚨 Error Handling

Common Issues

Issue: "Folder not found"

# Solution: Create folder first
mkdir "C:\WatchFolder"
ZPL2PDF.exe start -l "C:\WatchFolder"

Issue: "Permission denied"

# Solution: Run with appropriate permissions
sudo ZPL2PDF start -l "/var/watch"  # Linux
# or run as administrator (Windows)

Issue: "Daemon already running"

# Solution: Stop existing daemon first
ZPL2PDF.exe stop
ZPL2PDF.exe start

Recovery Procedures

# Check daemon status
ZPL2PDF.exe status

# If unresponsive, force stop
ZPL2PDF.exe stop

# Check for orphaned processes
ps aux | grep ZPL2PDF  # Linux
tasklist | findstr ZPL2PDF  # Windows

# Clean restart
ZPL2PDF.exe start

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📈 Performance Optimization

Resource Management

# Monitor resource usage
top -p $(pgrep ZPL2PDF)  # Linux
tasklist /FI "IMAGENAME eq ZPL2PDF.exe"  # Windows

Batch Processing

# Process large batches efficiently
ZPL2PDF.exe start -l "./batch_folder" -d 203  # Standard quality for speed

Memory Optimization

# Restart daemon periodically for long-running processes
# Create cron job (Linux) or scheduled task (Windows)
0 2 * * * ZPL2PDF stop && ZPL2PDF start

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🔗 Integration Examples

Windows Batch Script

@echo off
echo Starting ZPL2PDF Daemon...
ZPL2PDF.exe start -l "C:\WatchFolder" -w 7.5 -h 15 -u in
echo Daemon started. Press any key to stop.
pause
ZPL2PDF.exe stop

Linux Shell Script

#!/bin/bash
echo "Starting ZPL2PDF Daemon..."
ZPL2PDF start -l "/var/watch" -w 100 -h 200 -u mm
echo "Daemon started. Press Ctrl+C to stop."
trap 'ZPL2PDF stop; exit' INT
wait

Docker Compose

version: '3.8'
services:
  zpl2pdf:
    image: brunoleocam/zpl2pdf:latest
    volumes:
      - ./watch:/app/watch
      - ./output:/app/output
    command: start -l /app/watch -w 7.5 -h 15 -u in
    restart: unless-stopped

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🔗 Related Topics

• Configuration - Global settings and preferences
• Performance Optimization - Speed and resource optimization
• Troubleshooting - Common issues and solutions
• Docker Deployment - Container-based deployment