Linux Process Management Commands Cheatsheet

ps - Display process information

$ ps                    # Show processes in current shell
$ ps aux                # Show all processes with detailed info
$ ps aux | grep nginx   # Find specific process
$ ps -ef                # Full format listing
$ ps -u username        # Show user's processes

Common columns: PID (Process ID), USER, %CPU, %MEM, VSZ (Virtual Memory), RSS (Physical Memory), TTY, STAT (State), START, TIME, COMMAND

pstree - Display processes in tree structure

$ pstree                # Show process tree
$ pstree -p             # Show with PIDs
$ pstree username       # Show user's process tree

top - Real-time process monitor

$ top                   # Interactive process viewer
$ top -u username       # Show user's processes
$ top -p PID            # Monitor specific process

htop - Interactive process viewer (enhanced)

$ htop                  # Better alternative to top
$ htop -u username      # Show user's processes

Provides color-coded display, mouse support, and easier navigation than top

btop++ / bottom - Modern process viewers

$ btop                  # Modern, beautiful process viewer
$ btop++                # C++ version with advanced features
$ bottom                # Rust-based alternative (btm)

Modern alternatives with beautiful TUI, graphs, and advanced monitoring capabilities. For more essential commands, see our Linux Commands cheatsheet.

lsof - List open files and processes

$ lsof                  # List all open files
$ lsof -u username      # Show user's open files
$ lsof -i :80           # Show processes using port 80
$ lsof -p PID           # Show files opened by process

Essential for troubleshooting network connections and file access. Learn more about network monitoring techniques.

kill - Send signal to terminate or interrupt a process

$ kill PID              # Send default signal (SIGTERM)
$ kill -9 PID           # Force kill (SIGKILL)
$ kill -15 PID          # Graceful termination (SIGTERM)
$ kill -l               # List all available signals
$ kill -SIGHUP PID      # Send hangup signal

Default signal is SIGTERM (15) which allows graceful shutdown. SIGKILL (9) forces immediate termination.

killall - Kill all processes that match a specific process name

$ killall nginx         # Kill all nginx processes
$ killall -9 nginx      # Force kill all nginx processes
$ killall -u username   # Kill all processes by user

pkill - Send signal to processes based on name or other attributes

$ pkill nginx           # Kill processes by name
$ pkill -9 nginx        # Force kill by name
$ pkill -u username     # Kill user's processes
$ pkill -t pts/0        # Kill processes on terminal

pgrep - Find process IDs of running programs based on given criteria

$ pgrep nginx           # Find PIDs by name
$ pgrep -u username     # Find user's process PIDs
$ pgrep -l nginx        # Show PIDs with names
$ pgrep -a nginx        # Show full command line

trap - Allows shell scripts to watch for and intercept signals

#!/bin/bash
# Trap signals in shell script
trap "echo 'Signal received!'; exit" SIGINT SIGTERM

# Your script here
while true; do
    echo "Running..."
    sleep 1
done

Useful for cleanup operations when script is interrupted

& - Execute command in background

$ command &             # Run command in background
$ long_script.sh &      # Run script in background
$ sleep 100 &           # Example background job

Allows you to continue using the terminal while command runs

jobs - List active jobs in current shell session

$ jobs                  # List all jobs
$ jobs -l               # Show with PID
$ jobs -r               # Show running jobs only
$ jobs -s               # Show stopped jobs only

Jobs are numbered [1], [2], etc. Use job number with % (e.g., %1)

bg - Send job to background

$ bg                    # Resume most recent stopped job in background
$ bg %1                 # Resume job 1 in background
$ bg %2                 # Resume job 2 in background

fg - Bring job to foreground

$ fg                    # Bring most recent job to foreground
$ fg %1                 # Bring job 1 to foreground
$ fg %2                 # Bring job 2 to foreground

nohup - Run process that will continue even if terminal is closed

$ nohup command &       # Run immune to hangups
$ nohup ./script.sh &   # Output saved to nohup.out
$ nohup command > output.log 2>&1 &  # Redirect output

Process continues running even after you log out or close the terminal. For automated task scheduling, check our Cron cheatsheet and learn about secure SSH session management.

nice - Run command with modified priority

$ nice command          # Run with default nice value (+10)
$ nice -n 10 command    # Run with nice value of 10
$ nice -n -5 command    # Higher priority (requires root)
$ nice -n 19 ./script.sh    # Lowest priority (least CPU)

renice - Change priority of running process

$ renice 10 -p PID      # Set nice value to 10 for process
$ renice -5 -p PID      # Increase priority (requires root)
$ renice 15 -u username # Change priority for user's processes
$ renice 10 -g groupname    # Change priority for group

Example: Running CPU-intensive tasks

# Run video encoding with low priority
$ nice -n 19 ffmpeg -i input.mp4 output.mp4

# Run backup with lower priority
$ nice -n 15 tar -czf backup.tar.gz /data/

# Adjust running process priority
$ renice 10 -p $(pgrep ffmpeg)

screen - Manage multiple terminal sessions

$ screen                # Start new screen session
$ screen -S name        # Start named session
$ screen -ls            # List all sessions
$ screen -r             # Reattach to session
$ screen -r name        # Reattach to named session
$ screen -d -r          # Detach and reattach

tmux - Modern terminal multiplexer

$ tmux                  # Start new tmux session
$ tmux new -s name      # Start named session
$ tmux ls               # List all sessions
$ tmux attach           # Attach to last session
$ tmux attach -t name   # Attach to named session
$ tmux kill-session -t name    # Kill session

glances - Comprehensive system monitor

$ glances               # Start monitoring
$ glances -t 2          # Update every 2 seconds
$ glances --export-csv file.csv    # Export to CSV

Monitors CPU, memory, network, disk I/O, and processes in one view

gtop - System monitoring dashboard for terminal

$ gtop                  # Beautiful terminal dashboard

Node.js-based system monitor with beautiful graphics

ps_aux - Displays detailed information about all active processes

$ ps aux                # Full process list
$ ps aux --sort=-%cpu   # Sort by CPU usage
$ ps aux --sort=-%mem   # Sort by memory usage

/proc - Virtual filesystem with process information

$ cat /proc/cpuinfo     # CPU information
$ cat /proc/meminfo     # Memory information
$ cat /proc/PID/status  # Process status
$ cat /proc/PID/cmdline # Process command line

Each running process has a directory under /proc with its PID

systemctl - Control systemd system and service manager

$ systemctl status service    # Check service status
$ systemctl start service     # Start service
$ systemctl stop service      # Stop service
$ systemctl restart service   # Restart service
$ systemctl list-units --type=service    # List all services

Essential for managing services like nginx, apache, and containerized applications. For container management, see our Docker cheatsheet. Advanced tips available in our Linux Admin Tips guide.