Process Management

Process management allows you to monitor, pause, and terminate running programs or background tasks. It’s an essential skill for simulation and development workflows — especially when a process becomes unresponsive, consumes too much CPU or memory, or runs longer than expected.

The commands and shortcuts covered here work across Linux (Ubuntu/WSL), macOS, and Windows (PowerShell/Command Prompt), with a few syntax differences noted below.

Process Management in Linux / macOS / WSL

Linux and macOS terminals share the same command set since both are UNIX-based. These commands also work identically in WSL (Windows Subsystem for Linux) when using Ubuntu or similar distributions.

Checking Active Processes

Command	Description	Example
top	Displays real-time CPU and memory usage of active processes	top
htop	Enhanced version of top (requires installation)	htop
ps aux	Lists all running processes	ps aux
grep	Filters process list by keyword	ps aux | grep python

Press q to exit top or htop.

Stopping a Process

Every running process has a unique PID (Process ID). To stop or kill a process, use the following commands:

Command	Description	Example
kill PID	Gracefully stops a process	kill 2431
kill -9 PID	Forcefully terminates a process	kill -9 2431

Use kill -9 only when the regular kill command doesn’t stop the process. It sends a termination signal that cannot be ignored.

Keyboard Shortcuts for Process Control

When you’re running a command or script directly in the terminal, these shortcuts are the quickest way to control processes:

Shortcut	Description
Ctrl + C	Stops (terminates) the currently running process
Ctrl + Z	Pauses the running process and sends it to the background
Ctrl + D	Ends terminal input or exits the session (useful for closing shells or ending input prompts)

You can manage background jobs using:

Command	Description
jobs	Lists suspended or background processes
fg %job_number	Brings a background job to the foreground
bg %job_number	Resumes a paused job in the background

Process Management in Windows (PowerShell / Command Prompt)

Windows has its own set of commands for viewing and managing active processes. These can be executed from PowerShell or Command Prompt.

Checking Active Processes

Command	Description	Example
tasklist	Lists all running processes	tasklist
Get-Process	PowerShell command to display process details	Get-Process
Get-Process | findstr python	Filters process list by keyword (similar to grep)	Get-Process | findstr python

Stopping a Process

Command	Description	Example
taskkill /PID <pid>	Terminates a process by PID	taskkill /PID 2431
taskkill /IM <name>	Terminates a process by name	taskkill /IM python.exe
Stop-Process -Name <name>	PowerShell command to stop a process	Stop-Process -Name python
Stop-Process -Id <pid>	PowerShell command to stop by PID	Stop-Process -Id 2431

For stubborn processes, use /F (force):

taskkill /F /IM python.exe

Summary

Process management is crucial for maintaining control over simulations, scripts, and background operations.

• Use top, ps, and kill in Linux, macOS, and WSL for real-time monitoring and control.
• Use tasklist, taskkill, or PowerShell commands like Get-Process and Stop-Process in Windows.
• Remember keyboard shortcuts: Ctrl + C to stop, Ctrl + Z to pause, and Ctrl + D to exit input or terminal sessions.

These tools help you efficiently manage processes, recover from hangs, and keep your system responsive during heavy computational workloads.