Monitor Linux Processes with `ps`

ps (process status) prints a snapshot of processes. Unlike top or htop, it does not continuously refresh, which makes it particularly useful in shell pipelines, scripts, and one-time diagnostics.

Current Terminal Processes

ps

All Processes

ps -e
ps -ef

ps -ef uses a Unix-style full-format listing with fields such as UID, PID, PPID, and command.

Choose Columns Explicitly

ps -eo pid,ppid,user,cmd,%cpu,%mem

This is useful when you want stable, focused output for inspection or scripts.

Sort by CPU or Memory

ps -eo pid,ppid,cmd,%cpu --sort=-%cpu | head
ps -eo pid,ppid,cmd,%mem --sort=-%mem | head

The GNU/procps --sort option may not be available in exactly the same form on every Unix-like system.

Inspect a Specific PID

ps -p 1234 -o pid,ppid,user,etime,cmd

Process Trees

ps -e --forest

Or use pstree when installed:

pstree -p

Find a Process by Name

Instead of parsing ps output with grep, use pgrep when possible:

pgrep -a nginx

Conclusion

ps is ideal for process snapshots and scriptable diagnostics. Combine explicit output columns, sorting, and PID filters to answer a specific question rather than scanning an unstructured process dump.