top flags & options

`-p`

Monitor specific process IDs only.

top -p 1234

top -p 1234,5678

`-u`

Show only processes owned by a specific user.

top -u www-data

`-d`

Set the delay between screen updates in seconds.

top -d 0.5

top -d 5

`-n`

Exit after a specified number of display iterations.

top -n 1

top -bn 3 > top-snapshot.txt

`-b`

Run in batch mode for scripting or piping output to a file.

top -bn 1 | head -20

`-H`

Show individual threads instead of just processes.

top -H

top -H -p 1234

Interactive keys

Press these keys while top is running to change the display.

# P   - sort by CPU usage
# M   - sort by memory usage
# k   - kill a process (enter PID)
# c   - toggle full command path
# 1   - toggle per-CPU core display
# q   - quit