lsof command

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Basic Syntax:

1	lsof [options] [file\|socket\|keyword]

a: Selects files or sockets that match all of the specified keywords.
c: Specifies a process ID (PID) to filter results by. For example, lsof -c 12345 would show only files and sockets used by process with PID 12345.
d: Specifies a directory to search for open files or sockets.
e: Excludes files or sockets that match the specified keyword(s).
f: Forces lsof to use a specific file type (e.g., FIFO, socket, etc.).
i: Selects Internet sockets only (default is all types of files and sockets).

k: Specifies a keyword or pattern to search for in file names.
n: Disables hostname lookup for network addresses.
p: Specifies a process name or executable name to filter results by.
r: Reverses the order of the output (i.e., shows files and sockets most recently used first).
s: Shows only socket information.
t: Specifies a file type to search for (e.g., REGULAR, DIRECTORY, etc.).
u: Shows only user-level information (i.e., open files and sockets used by users).
w: Sets the minimum number of bytes required for an output line.

file: Specifies a file name or pattern to search for.
socket: Specifies a socket name or pattern to search for.
keyword: Specifies a keyword or pattern to search for in file names, socket names, or other metadata.

lsof

lsof -i

1	lsof -c 12345

1	lsof -k ssh

1	lsof -f FIFO

You can combine options to create more complex queries.
Use the a option with multiple keywords to find files or sockets that match all of them.
Be careful when using lsof, as it may show sensitive information (e.g., password files).
On Linux systems, you may need to use the sudo command to run lsof if you don’t have permission to access certain system resources.