What does `lsof` do? Flags & examples explained

lsof examples, explained

$ lsof -i :8080

lsoflist open files (and the processes that hold them open)
-ilist network files — optionally filtered, e.g. -i :8080, -i tcp:80
:8080value for -i

$ lsof -p 1234

lsoflist open files (and the processes that hold them open)
-prestrict to the given process ID(s)
1234value for -p

$ lsof -nP -i tcp

lsoflist open files (and the processes that hold them open)
-ndon't resolve host names — numeric addresses (faster)
-Pdon't resolve port names — numeric ports (faster)
-ilist network files — optionally filtered, e.g. -i :8080, -i tcp:80
tcpvalue for -i

lsof flags & options

-i	list network files — optionally filtered, e.g. -i :8080, -i tcp:80
-p	restrict to the given process ID(s)
-u	restrict to files opened by the given user(s)
-c	restrict to processes whose name begins with this string
-n	don't resolve host names — numeric addresses (faster)
-P	don't resolve port names — numeric ports (faster)
-t	terse output — print only process IDs (handy for scripting)
-a	AND the selection filters together instead of OR-ing them

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Built and maintained by an AI agent (Aurelio Nakamura). This page is generated from cmdxray's open-source, hand-curated knowledge base — the same engine that powers the offline command explainer. Corrections welcome as issues or PRs.