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Service and Process Management Guide: Bash vs. PowerShell

Last updated: December 18, 2025
Author: Paul Namalomba
- SESKA Computational Engineer
- Software Developer
- PhD Candidate (Civil Engineering Spec. Computational and Applied Mechanics)

Contact: kabwenzenamalomba@gmail.com
Website: paulnamalomba.github.io

Framework License: MIT

Overview

This guide provides a comparative technical reference for managing system services and processes in Linux (via Bash/Systemd) and Windows (via PowerShell). It covers essential commands and concepts for both operating systems, focusing on service control, process management, and best practices.

Contents

Part 1: System Services Management

This section covers the management of background services (daemons in Linux, Services in Windows).

1.1 Linux: Systemd (systemctl)

systemd is the init system and service manager for most modern Linux distributions. systemctl is the primary command-line utility for introspection and control.

Basic Service Control

The generic syntax is sudo systemctl [command] [service_name].

  • Start a service: bash sudo systemctl start nginx
  • Stop a service: bash sudo systemctl stop nginx
  • Restart a service: (Stops and then starts) bash sudo systemctl restart nginx
  • Reload configuration: (Reloads config without dropping connections, if supported) bash sudo systemctl reload nginx
  • Check status: (Shows active state, PIDs, and recent logs) bash systemctl status nginx

Boot Management

Controls whether a service launches automatically when the OS boots.

  • Enable at boot: (Creates symlinks) bash sudo systemctl enable nginx
  • Disable at boot: (Removes symlinks) bash sudo systemctl disable nginx
  • Check if enabled: bash systemctl is-enabled nginx

Logging (Journalctl)

systemd uses a binary logger called the journal.

  • View logs for a specific service: bash # -u = unit, -f = follow (tail), -n = number of lines journalctl -u nginx -f -n 50

1.2 Windows: PowerShell Service Cmdlets

PowerShell uses the *-Service noun for service management.

Basic Service Control

  • Get Service Status: powershell Get-Service -Name W3SVC
  • Start a service: powershell Start-Service -Name W3SVC
  • Stop a service: powershell Stop-Service -Name W3SVC
  • Restart a service: powershell Restart-Service -Name W3SVC
  • Filtering Services: PowerShell allows object-based filtering rather than text grep. powershell # Find all running services starting with 'W' Get-Service | Where-Object { $_.Status -eq 'Running' -and $_.Name -like 'W*' }

Boot Management (Startup Types)

Windows uses "Startup Types" (Automatic, Manual, Disabled) rather than just enable/disable flags.

  • Set to Automatic (Enable at boot): powershell Set-Service -Name W3SVC -StartupType Automatic
  • Set to Disabled (Disable at boot): powershell Set-Service -Name W3SVC -StartupType Disabled
  • Set to Manual: powershell Set-Service -Name W3SVC -StartupType Manual

Part 2: Process Control & Supervisor

This section compares the Linux supervisor tool (process control system) with Windows process management.

2.1 Linux: Supervisor (supervisorctl)

Supervisor is a client/server system that allows its users to monitor and control a number of processes on UNIX-like operating systems. It is often used to keep applications running (respawning them if they crash).

Key Commands

  • Enter Interactive Shell: bash sudo supervisorctl
  • Check Status of All Processes: bash sudo supervisorctl status
  • Start/Stop specific process: bash sudo supervisorctl start my_app_worker sudo supervisorctl stop my_app_worker
  • Restart specific process: bash sudo supervisorctl restart my_app_worker
  • Reload Config (Reread & Update):
    • reread: Reloads the configuration files but doesn't restart processes.
    • update: Restarts processes whose configuration has changed. bash sudo supervisorctl reread sudo supervisorctl update
  • Tail Logs: Supervisor captures stdout/stderr. bash sudo supervisorctl tail -f my_app_worker

2.2 Windows: PowerShell Process Management

Note: Windows does not have a built-in 1:1 equivalent to Supervisor for process grouping and automatic respawning without external tools. Native PowerShell commands interact directly with the OS process table.

Native Process Cmdlets

  • List Processes: powershell # Equivalent to 'ps aux' or 'top' Get-Process
  • Find Specific Process: powershell Get-Process -Name chrome # Or via ID Get-Process -Id 4520
  • Stop (Kill) Process: powershell Stop-Process -Name notepad # Force kill Stop-Process -Name notepad -Force
  • Start a Process: powershell Start-Process -FilePath "C:\Path\To\App.exe" -ArgumentList "-config config.json"

Advanced Inspection (WMI/CIM)

Get-Process does not show the full command line arguments by default. You need WMI or CIM for this.

  • Get Command Line Arguments: powershell Get-CimInstance Win32_Process | Select-Object ProcessId, Name, CommandLine | Format-List

Architectural Equivalents to Supervisor

To achieve "keep-alive" functionality (respawning apps if they crash) on Windows, you typically wrap the executable as a Windows Service.

  1. NSSM (Non-Sucking Service Manager): The industry standard 3rd-party tool for running arbitrary .exe files as services. powershell # Installation (if nssm is in path) nssm install MyAppService "C:\path\to\app.exe" nssm set MyAppService AppDirectory "C:\path\to" nssm start MyAppService

  2. Native New-Service: Can create services, but the executable must strictly implement the Windows Service API (unlike NSSM which handles the API wrapper). powershell New-Service -Name "MyApp" -BinaryPathName "C:\path\to\service-compatible-app.exe" -StartupType Automatic

Part 3: Service Configuration & Dependencies

Understanding how services are defined and how they relate to one another is crucial for system stability.

3.1 Linux: Systemd Unit Files

In Systemd, services are defined in .service files (Unit files), typically located in /etc/systemd/system/.

Anatomy of a Unit File

A basic service file (/etc/systemd/system/myapp.service) looks like this:

[Unit]
Description=My Custom App
After=network.target postgresql.service  # Start after these
Requires=postgresql.service              # Strong dependency

[Service]
Type=simple
User=www-data
ExecStart=/usr/bin/python3 /opt/myapp/main.py
Restart=on-failure                       # Auto-restart if crashes
RestartSec=5s

[Install]
WantedBy=multi-user.target               # Enable for standard multi-user runlevel
  • Reloading Daemon: After editing a unit file, you must run: bash sudo systemctl daemon-reload

3.2 Windows: Service Dependencies & Recovery

Windows services store configuration in the Registry. While Set-Service covers basics, sc.exe (Service Control) or WMI is often needed for advanced configuration.

Managing Dependencies

  • View Dependencies (PowerShell): ```powershell # Services that depend on 'LanmanWorkstation' Get-Service -Name LanmanWorkstation -DependentServices

    Services that 'LanmanWorkstation' depends on

    Get-Service -Name LanmanWorkstation -RequiredServices ```

Service Recovery (Auto-Restart)

Configuring a service to restart automatically upon failure is common. PowerShell's Set-Service doesn't expose recovery options directly; use sc.exe (legacy but effective) or CIM.

  • Configure Restart on Failure (cmd/sc.exe): powershell # Set failure actions: Restart after 1st, 2nd, and subsequent failures (delay 60s) sc.exe failure "W3SVC" reset= 86400 actions= restart/60000/restart/60000/restart/60000

Part 4: Background Jobs & Process Priority

Managing ad-hoc background tasks and system resource allocation.

4.1 Linux: Job Control & Nice

Shell Job Control

Bash allows running commands in the background of the current shell session.

  • Start in background: Append & bash long_running_script.sh &
  • List jobs: bash jobs
  • Bring to foreground: bash fg %1

Process Priority (Nice)

  • Start with lower priority: (Higher nice value = lower priority, range -20 to 19) bash nice -n 10 ./backup.sh
  • Change priority of running process: bash renice -n 10 -p 1234

4.2 Windows: PowerShell Jobs & Priority

PowerShell Jobs

PowerShell jobs run in a separate process (wsmprovhost.exe), allowing the main console to remain responsive.

  • Start a Job: powershell $job = Start-Job -ScriptBlock { Get-ChildItem -Recurse C:\Windows }
  • Check Status: powershell Get-Job
  • Get Results: (Removes data from queue unless -Keep is used) powershell Receive-Job -Job $job

Process Priority

You can adjust the PriorityClass of a process object.

  • Set Priority: powershell $proc = Get-Process -Name "notepad" $proc.PriorityClass = "BelowNormal" # Options: Idle, BelowNormal, Normal, AboveNormal, High, RealTime

This guide covers service and process management on Linux and Windows.