lsof -p process-id
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Lsof lists on its standard output file information about files opened by processes
[...]
-p s This option excludes or selects the listing of files for the
processes whose optional process IDentification (PID) numbers
are in the comma-separated set s - e.g., ''123'' or
''123,^456''. (There should be no spaces in the set.)
PID numbers that begin with '^' (negation) represent exclu-
sions.
Multiple process ID numbers are joined in a single ORed set
before participating in AND option selection. However, PID
exclusions are applied without ORing or ANDing and take effect
before other selection criteria are applied.
[...]
+|-r [t[m]]
This option puts lsof in repeat mode. There lsof lists open
files as selected by other options, delays t seconds (default
fifteen), then repeats the listing, delaying and listing
repetitively until stopped by a condition defined by the pre-
fix to the option.
If the prefix is a '-', repeat mode is endless. Lsof must be
terminated with an interrupt or quit signal.
If the prefix is '+', repeat mode will end the first cycle no
open files are listed