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lsof
List open files.
SYNTAX
lsof [options] [names]
OPTIONS
-? -h Display help text.
-a Causes the list selection options to be ANDed.
-A A Specify A as an alternate name list file where
the kernel addresses of the dynamic modules might be
found. This option is available on systems whose AFS kernel
code is implemented via dynamic modules.
-b This option causes lsof to avoid kernel functions that might
block - lstat(2), readlink(2), and stat(2).
See the full lsof man page for more on using this option.
-c c This option selects the listing of files for processes execut-
ing the command that begins with the characters of c.
Multiple commands may be specified, using multiple -c options.
They are joined in a single ORed set before participating in
AND option selection.
If c begins and ends with a slash ('/'), the characters
between the slashes is interpreted as a regular expression.
Shell meta-characters in the regular expression must be quoted
to prevent their interpretation by the shell. The closing
slash may be followed by these modifiers:
b the regular expression is a basic one.
i ignore the case of letters.
x the regular expression is an extended one
(default).
See the lsof FAQ for more
+c w This option defines the maximum number of initial characters
of the name of the UNIX command associated with a process to
be printed in the COMMAND column. (The default is nine.)
If w is zero ('0'), all command characters will be printed.
If w is less than the length of the column title, ``COMMAND'',
it will be raised to that length.
-C This option disables the reporting of any path name components
from the kernel's name cache. See the KERNEL NAME CACHE sec-
tion for more information.
+d s This option causes lsof to search for all open instances of
directory s and the files and directories it contains at its
top level. This option does NOT descend the directory tree,
rooted at s, nor does it follow symbolic links within it. The
+D D option may be used to request a full-descent directory
tree search, rooted at directory D.
Note: the authority of the user of this option limits it to
searching for files that the user has permission to examine
with the system stat(2) function.
-d s This option specifies a list of file descriptors (FDs) to
exclude from or include in the output listing. The file
descriptors are specified in the comma-separated set s - e.g.,
`cwd,1,3', `^6,^2'. (There should be no spaces in the
set.)
The list is an exclusion list if all entries of the set begin
with '^'. It is an inclusion list if no entry begins with
'^'. Mixed lists are not permitted.
A file descriptor number range may be in the set as long as
neither member is empty, both members are numbers, and the
ending member is larger than the starting one - e.g., ``0-7''
or ``3-10''. Ranges may be specified for exclusion if they
have the '^' prefix - e.g., ``^0-7'' excludes all file
descritors 0 through 7.
Multiple file descriptor numbers are joined in a single ORed
set before participating in AND option selection.
When there are exclusion and inclusion members in the set,
lsof reports them as errors and exits with a non-zero return
code.
See the description of File Descriptor (FD) output values in
the OUTPUT section for more information on file descriptor
names.
+D D This option causes lsof to search for all open instances of
directory D and all the files and directories it contains to
its complete depth. Symbolic links within directory D are
ignored - i.e, not followed.
-D D This option directs lsof's use of the device cache file. The
use of this option is sometimes restricted. See the DEVICE
CACHE FILE section and the sections that follow it for more
information on this option.
-D must be followed by a function letter; the function letter
may optionally be followed by a path name. Lsof recognizes
these function letters:
? - report device cache file paths
b - build the device cache file
i - ignore the device cache file
r - read the device cache file
u - read and update the device cache file
The b, r, and u functions, accompanied by a path name, are
sometimes restricted. When these functions are restricted,
they will not appear in the description of the -D option that
accompanies -h or -? option output. See the full man page.
+|-f [cfgGn]
f by itself clarifies how path name arguments are to be inter-
preted. When followed by c, f, g, G, or n in any combination
it specifies that the listing of kernel file structure infor-
mation is to be enabled (`+') or inhibited (`-').
Normally a path name argument is taken to be a file system
name if it matches a mounted-on directory name reported by
mount(8), or if it represents a block device, named in the
mount output and associated with a mounted directory name.
When +f is specified, all path name arguments will be taken to
be file system names, and lsof will complain if any are not.
This can be useful, for example, when the file system name
(mounted-on device) isn't a block device. This happens for
some CD-ROM file systems.
When -f is specified, all path name arguments will be taken to
be simple files. Thus, for example, the ``-f /'' arguments
direct lsof to search for open files with a `/' path name, not
all open files in the `/' (root) file system.
Be careful to make sure +f is properly terminated and isn't
followed by a character (e.g., of the file or file system
name) that might be taken as a parameter. For example, use
``--'' after +f as in this example.
$ lsof +f -- /file/system/name
The listing of information from kernel file structures,
requested with the +f [cfgGn] option form, is normally inhib-
ited, and is not available for some dialects - e.g.,
/proc-based Linux. When the prefix to f is a plus sign (`+'),
these characters request file structure information:
c file structure use count
f file structure address
g file flag abbreviations
G file flags in hexadecimal
n file structure node address
When the prefix is minus (`-') the same characters disable the
listing of the indicated values.
File structure addresses, use counts, flags, and node
addresses may be used to detect more readily identical files
inherited by child processes and identical files in use by
different processes. Lsof column output can be sorted by out-
put columns holding the values and listed to identify
identical file use, or lsof field output can be parsed by an
AWK or Perl post-filter script, or by a C program.
-F f This option specifies a character list, f, that selects the
fields to be output for processing by another program, and the
character that terminates each output field. Each field to be
output is specified with a single character in f. The field
terminator defaults to NL, but may be changed to NUL (000).
See the OUTPUT FOR OTHER PROGRAMS section for a description of
the field identification characters and the field output pro-
cess.
When the field selection character list is empty, all fields
are selected (except the raw device field for compatibility
reasons) and the NL field terminator is used.
When the field selection character list contains only a zero
(`0'), all fields are selected (except the raw device field
for compatibility reasons) and the NUL terminator character is
used.
Other combinations of fields and their associated field termi-
nator character must be set with explicit entries in f, as
described in the OUTPUT FOR OTHER PROGRAMS section.
When a field selection character identifies an item lsof does
not normally list - e.g., PPID, selected with -R - specifica-
tion of the field character - e.g., ``-FR'' - also selects the
listing of the item.
When the field selection character list contains the single
character `?', lsof will display a help list of the field
identification characters. (Escape the `?' character as your
shell requires.)
-g [s] This option selects the listing of files for the processes
whose optional process group IDentification (PGID) numbers are
in the comma-separated set s - e.g., `123' or `123,456'.
(There should be no spaces in the set.)
Multiple PGID numbers are joined in a single ORed set before
participating in AND option selection.
The -g option also enables the output display of PGID numbers.
When specified without a PGID set that's all it does.
-i [i] This option selects the listing of files any of whose Internet
address matches the address specified in i. If no address is
specified, this option selects the listing of all Internet and
x.25 (HP-UX) network files.
If -i4 or -i6 is specified with no following address, only
files of the indicated IP version, IPv4 or IPv6, are dis-
played.
Multiple addresses may be specified with multiple -i options.
An Internet address is specified in the form:
[46][protocol][@hostname|hostaddr][:service|port]
where:
46 specifies the IP version, IPv4 or IPv6
that applies to the following address.
'6' may be be specified only if the UNIX
dialect supports IPv6. If neither '4' nor
'6' is specified, the following address
applies to all IP versions.
protocol is a protocol name - TCP or UDP.
hostname is an Internet host name. Unless a
specific IP version is specified, open
network files associated with host names
of all versions will be selected.
hostaddr is a numeric Internet IPv4 address in
dot form; or an IPv6 numeric address in
colon form, enclosed in brackets, if the
UNIX dialect supports IPv6. When an IP
version is selected, only its numeric
addresses may be specified.
service is an /etc/services name - e.g., smtp -
or a list of them.
port is a port number, or a list of them.
At least one address component - 4, 6, protocol, ,IR hostname
, hostaddr, or service - must be supplied.
Some sample addresses:
-i6 - IPv6 only
TCP:25 - TCP and port 25
@1.2.3.4 - Internet IPv4 host address 1.2.3.4
@[3ffe:1e<file_system>bc::1]:1234 - Internet IPv6 host address 3ffe:1ebc::1, port 1234
UDP:who - UDP who service port
TCP@lsof.itap:513 - TCP, port 513 and host name lsof.itap
tcp@foo:1-10,smtp,99 - TCP, ports 1 through 10, service name smtp, port 99, host name foo
tcp@bar:smtp-nameserver - TCP, ports smtp through nameserver, host bar
:time - either TCP or UDP time service port
-k k This option specifies a kernel name list file, k, in place of
/vmunix, /mach, etc.
-l This option inhibits the conversion of user ID numbers to
login names. It is also useful when login name lookup is
working improperly or slowly.
+|-L [l] This option enables (`+') or disables (`-') the listing of
file link counts, where they are available - e.g., they aren't
available for sockets, or most FIFOs and pipes.
When +L is specified without a following number, all link
counts will be listed. When -L is specified (the default), no
link counts will be listed.
When +L is followed by a number, only files having a link
count less than that number will be listed. (No number may
follow -L.) A specification of the form ``+L1'' will select
open files that have been unlinked. A specification of the
form ``+aL1 '' will select unlinked open files on
the specified file system.
For other link count comparisons, use field output (-F) and a
post-processing script or program.
-m m This option specifies a kernel memory file, c, in place of
/dev/kmem or /dev/mem - e.g., a crash dump file.
+|-M Enables (+) or disables (-) the reporting of portmapper regis-
trations for local TCP and UDP ports.
See the lsof FAQ for more detail.
-n This option inhibits the conversion of network numbers to host
names for network files. Inhibiting conversion may make lsof
run faster. It is also useful when host name lookup is not
working properly.
-N This option selects the listing of NFS files.
-o This option directs lsof to display file offset at all times.
Consult the lsof FAQ for more information.
The -o and -s options are mutually exclusive.
-o o This option defines the number of decimal digits (o) to be
printed after the `0t' for a file offset before the form is
switched to `0x...'. An o value of zero (unlimited) directs
lsof to use the `0t' form for all offset output.
The default number is normally 8.
-O This option directs lsof to bypass the strategy it uses to
avoid being blocked by some kernel operations.
Use this option cautiously.
-p s This option selects the listing of files for the processes
whose ID numbers are in the comma-separated set s - e.g.,
`123' or `123,456'. (There should be no spaces in the set.)
Multiple process ID numbers are joined in a single ORed set
before participating in AND option selection.
-P This option inhibits the conversion of port numbers to port
names for network files. Inhibiting the conversion may make
lsof run a little faster. It is also useful when host name
lookup is not working properly.
+|-r [t] 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 - and of course when lsof is stopped
with an interrupt or quit signal. When repeat mode ends
because no files are listed, the process exit code will be
zero if any open files were ever listed; one, if none were
ever listed.
Lsof marks the end of each listing: if field output is in
progress (the -F, option has been specified), the marker is
`m'; otherwise the marker is ``========''. The marker is fol-
lowed by a NL character.
Repeat mode reduces lsof startup overhead, so it is more effi-
cient to use this mode than to call lsof repetitively from a
shell script, for example.
To use repeat mode most efficiently, accompany +|-r with spec-
ification of other lsof selection options, so the amount of
kernel memory access lsof does will be kept to a minimum.
Options that filter at the process level - e.g., -c, -g, -p,
-u - are the most efficient selectors.
Repeat mode is useful when coupled with field output (see the
-F, option description) and a supervising awk or Perl script,
or a C program.
-R List the Parent Process IDentification number in the PPID column.
-s This option directs lsof to display file size at all times.
It causes the SIZE/OFF output column title to be changed to
SIZE. If the file does not have a size, nothing is displayed.
The -o (without a following decimal digit count) and -s
options are mutually exclusive.
Since some types of files don't have true sizes - sockets,
FIFOs, pipes, etc. - lsof displays for their sizes the content
amounts in their associated kernel buffers, if possible.
-S [t] This option specifies an optional time-out seconds value for
kernel functions - lstat(2), readlink(2), and stat(2) - that
might otherwise deadlock. The minimum for t is two; the
default is fifteen.
-T [t] Display TCP/TPI information
-T with no following key characters disables TCP/TPI info.
-T with following character(s) selects the reporting info:
q selects queue length reporting.
s selects state reporting.
w selects window size reporting (not all dialects).
-t Terse output with process identifiers only and no header -
e.g., so that the output may be piped to kill(1).
This option selects the -w option.
-u s This option selects the listing of files for the user whose
login names or user ID numbers are in the comma-separated set
s - e.g., `abe', or `548,root'. (There should be no
spaces in the set.)
Multiple login names or user ID numbers are joined in a single
ORed set before participating in AND option selection.
If a login name or user ID is preceded by a `^', it becomes a
negation - i.e., files of processes owned by the login name or
user ID will never be listed. For example, to direct lsof to
exclude the listing of files belonging to root processes
specify `-u^root' or `-u^0'.
-U This option selects the listing of UNIX domain socket files.
-v This option selects the listing of lsof version information,
including: revision number; when the lsof binary was con-
structed; who constructed the binary and where; the name of
the compiler used to construct the lsof binary; the version
number of the compiler when readily available; the compiler
and loader flags used to construct the lsof binary; and system
information, typically the output of uname's -a option.
-V This option directs lsof to indicate the items it was asked to
list and failed to find - command names, file names, Internet
addresses or files, login names, NFS files, PIDs, PGIDs, and
UIDs.
When other options are ANDed to search options, or com-
pile-time options restrict the listing of some files, lsof may
not report that it failed to find a search item when an ANDed
option or compile-time option prevents the listing of the open
file containing the located search item.
+|-w Enables (+) or disables (-) the suppression of warning mes-
sages. The -t option selects the -w option.
-X This is a dialect-specific option.
-- The double minus sign option is a marker that signals the end
of the keyed options. It may be used, for example, when the
first file name begins with a minus sign. It may also be used
when the absence of a value for the last keyed option must be
signified by the presence of a minus sign in the following
option and before the start of the file names.
names These are path names of specific files to list. Symbolic
links are resolved before use. The first name may be sepa-
rated from the preceding options with the ``--'' option.
Multiple file names are joined in a single ORed set before
participating in AND option selection.
Notes
An open file may be a regular file, a directory, a block special file, a character special file, an executing text reference, a library, a stream or a network file (Internet socket, NFS file or UNIX domain socket.) A specific file or all the files in a file system may be selected by path.
Instead of a formatted display, lsof can produce output that can be parsed by other programs. See the -F, option.
In addition to producing a single output list, lsof will run in repeat mode. In repeat mode it will produce output, delay, then repeat the output operation until stopped with an interrupt or quit signal. See the +|-r [t] option.
Examples
List files currently open by me and my processes. lsof List files currently open on the entire system. sudo lsof List open network connections on the entire system. sudo lsof -i List open files on the "FW Drive" volume; useful for figuring out why you can't eject/dismount a disk because something is using it. sudo lsof "/Volumes/FW Drive"
"It is when we all play safe that we create a world of the utmost insecurity" - Dag Hammarskjold, United Nations secretary general
lsof FAQ - FTP link to full documentation.
Related commands:
sudo - Execute a command as another user
kill - Stop a process from running
ps - List running processes (returns PID)
uname - Print system information
Equivalent BASH command:
