[SOLVED] How to query the amount of free file handles from the OS?
lazarus / 32-Linux

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Hartmut · 2023-06-17 09:16

I have the suspicion that my program does not close all files, which
it opened, because after 18 days it stops doing it's job without
cognizable reason. My program uses a foreign library which might be
the causer.

I assume that Linux (in my case Ubuntu Server) can not open an endless
amount of file handles at the same time.

Question1: is it possible to query, how many free file handles are
currently left in Linux?

Question2: is it possible to query, how many file handles a certain
program is currently occupying?

Thanks in advance.

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zeljko · 2023-06-17 11:09

Goto /proc/YOURAPPPID and see how many files are open, or use lsof
with pid param to see all relevant informations.

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Hartmut · 2023-06-17 14:29

Thanks zeljko for your answer. I found out:

With "ls -l /proc/<PID>/fd" you can get a list of all opened file-
handles of a PID.

With "lsof -p <PID>" you also can get a list of all opened file-
handles of a PID.

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zeljko · 2023-06-17 14:39

Also with ulimit you can increase number of opened file descriptors
per process if needed

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Hartmut · 2023-06-17 15:17

Thanks.