LSOF(8)LSOF(8)NAMElsof - list open files
SYNOPSISlsof [ -?abChlnNOPRstUvVX ] [ -A A ] [ -c c ] [ +|-d d ] [
+|-D D ] [ +|-f [cfgGn] ] [ -F [f] ] [ -g [s] ] [ -i [i] ]
[ -k k ] [ +|-L [l] ] [ -m m ] [ +|-M ] [ -o [o] ] [ -p s
] [ +|-r [t] ] [ -S [t] ] [ -T [t] ] [ -u s ] [ +|-w ] [
-- ] [names]
DESCRIPTION
Lsof revision 4.49 lists information about files opened by
processes for the following UNIX dialects:
AIX 4.1.[45], 4.2[.1], and 4.3[.123]
BSDI BSD/OS 2.1, 3.[01], and 4.[01] for Intel-based systems
DC/OSx 1.1 for Pyramid systems
DEC OSF/1, Digital UNIX, Tru64 UNIX 2.0, 3.2, 4.0, and 5.0
FreeBSD 2.1.[67], 2.2[.x], 3.[01234], 4.0, and 5.0 for Intel-
based systems
HP-UX 9.01, 10.20, and 11.00
Linux 2.0.3[2346], 2.1.x, and 2.2.x for Intel-based systems
NetBSD 1.[234] for Intel and SPARC-based systems
NEXTSTEP 3.[13] for NEXTSTEP architectures
OpenBSD 2.[0123456] for Intel-based systems
OpenStep 4.x
Reliant UNIX 5.4[34] for Pyramid systems
SCO OpenServer Release 3.0 and 5.0.[0245] for Intel-based
systems
SCO UnixWare 2.1.[123] and 7[[.0].1] for Intel-based systems
Sequent PTX 2.1.9, 4.2.[13], 4.[34], and 4.4[.124] for
Sequent systems
Solaris 2.5.1, 2.6, 7, 8 BETA, and 8 BETA-Refresh
SunOS 4.1.x
Ultrix 4.2
(See the DISTRIBUTION section of this manual page for
information on how to obtain the latest lsof revision.)
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 will produce output
that can be parsed by other programs. See the -F, option
description, and the OUTPUT FOR OTHER PROGRAMS section for
more information.
In addition to producing a single output list, lsof will
run in repeat mode. In repeat mode it will produce out-
put, delay, then repeat the output operation until stopped
with an interrupt or quit signal. See the +|-r [t] option
Revision-4.49 1
LSOF(8)LSOF(8)
description for more information.
OPTIONS
In the absence of any options, lsof lists all open files
belonging to all active processes.
If any list request option is specified, other list
requests must be specifically requested - e.g., if -U is
specified for the listing of UNIX socket files, NFS files
won't be listed unless -N is also specified; or if a user
list is specified with the -u option, UNIX domain socket
files, belonging to users not in the list, won't be listed
unless the -U option is also specified.
Normally list options that are specifically stated are
ORed - i.e., specifying the -i option without an address
and the -ufoo option produces a listing of all network
files OR files belonging to processes owned by user
``foo''. One exception is the `^' (negated) login name or
user ID (UID) specified with the -u option. Since it is
an exclusion, it is applied without ORing or ANDing and
takes effect before any other selection criteria are
applied.
The -a option may be used to AND the selections. For
example, specifying -a, -U, and -ufoo produces a listing
of only UNIX socket files that belong to processes owned
by user ``foo''.
Caution: the -a option causes all list selection options
to be ANDed; it can't be used to cause ANDing of selected
pairs of selection options by placing it between them,
even though its placement there is acceptable. Wherever
-a is placed, it causes the ANDing of all selection
options.
Items of the same selection set - command names, file
descriptors, network addresses, process identifiers, user
identifiers - are joined in a single ORed set and applied
before the result participates in ANDing. Thus, for exam-
ple, specifying -i@aaa.bbb, -i@ccc.ddd, -a, and -ufff,ggg
will select the listing of files that belong to either
login ``fff'' OR ``ggg'' AND have network connections to
either host aaa.bbb OR ccc.ddd.
Options may be grouped together following a single prefix
-- e.g., the option set ``-a -b -C'' may be stated as
-abC. However, since values are optional following +|-f,
-F, -g, -i, +|-L, -o, +|-r, -S, and -T, when you have no
values for them be careful that the following character
isn't ambiguous. For example, -Fn might represent the -F
and -n options, or it might represent the n field identi-
fier character following the -F option. When ambiguity is
possible, start a new option with a `-' character - e.g.,
Revision-4.49 2
LSOF(8)LSOF(8)
``-F -n''. If the next option is a file name, follow the
possibly ambiguous option with ``--'' - e.g., ``-F --
name''.
Either the `+' or the `-' prefix may be applied to a group
of options. Options that don't take on separate meanings
for each prefix - e.g., -i - may be grouped under either
prefix. Thus, for example, ``+M -i'' may be stated as
``+Mi'' and the group means the same as the separate
options. Be careful of prefix grouping when one or more
options in the group does take on separate meanings under
different prefixes - e.g., +|-M; ``-iM'' is not the same
request as ``-i +M''. When in doubt, use separate options
with appropriate prefixes.
-? -h These two equivalent options select a usage
(help) output list. Lsof displays a shortened
form of this output when it detects an error in
the options supplied to it, after it has dis-
played messages explaining each error. (Escape
the `?' character as your shell requires.)
-a This option causes list selection options to be
ANDed, as described above.
-A A This option is available on systems configured
for AFS whose AFS kernel code is implemented via
dynamic modules. It allows the lsof user to
specify A as an alternate name list file where
the kernel addresses of the dynamic modules might
be found. See the 00FAQ file of the lsof distri-
bution for more information about dynamic mod-
ules, their symbols, and how they affect lsof.
-b This option causes lsof to avoid kernel functions
that might block - lstat(2), readlink(2), and
stat(2).
See the BLOCKS AND TIMEOUTS and AVOIDING KERNEL
BLOCKS sections for information on using this
option.
-c c This option selects the listing of files for pro-
cesses executing the command that begins with the
characters of c. Multiple commands may be speci-
fied, using multiple -c options. They are joined
in a single ORed set before participating in AND
option selection.
-C This option disables the reporting of any path
name components from the kernel's name cache.
See the KERNEL NAME CACHE section for more infor-
mation.
Revision-4.49 3
LSOF(8)LSOF(8)
+d s This option causes lsof to search for all open
instances of directory s and the files and direc-
tories 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 selects the listing of files whose
file descriptors are in the comma-separated set s
- e.g., ``1,3'' or ``6,cwd,2''. (There should be
no spaces in the set.)
A file descriptor number range may be included 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''.
Multiple file descriptor numbers are joined in a
single ORed set before participating in AND
option selection.
See the description of File Descriptor (FD) out-
put values in the OUTPUT section for more infor-
mation 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.
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.
Further note: lsof may process this option slowly
and require a large amount of dynamic memory to
do it. This is because it must descend the
entire directory tree, rooted at D, calling
stat(2) for each file and directory, building a
list of all the files it finds, and searching
that list for a match with every open file. When
directory D is large, these steps can take a long
time, so use this option prudently.
-D D This option directs lsof's use of the device
Revision-4.49 4
LSOF(8)LSOF(8)
cache file. The use of this option is sometimes
restricted. See the DEVICE CACHE FILE section
and the sections that follow it for more informa-
tion 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 let-
ters:
? - 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 func-
tions are restricted, they will not appear in the
description of the -D option that accompanies -h
or -? option output. See the DEVICE CACHE FILE
section and the sections that follow it for more
information on these functions and when they're
restricted.
The ? function reports the read-only and write
paths that lsof can use for the device cache
file, the names of any environment variables
whose values lsof will examine when forming the
device cache file path, and the format for the
personal device cache file path. (Escape the `?'
character as your shell requires.)
When available, the b, r, and u functions may be
followed by the device cache file's path. The
standard default is .lsof_hostname in the home
directory of the real user ID that executes lsof,
but this could have been changed when lsof was
configured and compiled. (The output of the -h
and -? options show the current default prefix -
e.g., ``.lsof''.) The suffix, hostname, is the
first component of the host's name returned by
gethostname(2).
When available, the b function directs lsof to
build a new device cache file at the default or
specified path.
The i function directs lsof to ignore the default
device cache file and obtain its information
about devices via direct calls to the kernel.
The r function directs lsof to read the device
cache at the default or specified path, but
Revision-4.49 5
LSOF(8)LSOF(8)
prevents it from creating a new device cache file
when none exists or the existing one is improp-
erly structured. The r function, when specified
without a path name, prevents lsof from updating
an incorrect or outdated device cache file, or
creating a new one in its place. The r function
is always available when it is specified without
a path name argument; it may be restricted by the
permissions of the lsof process.
When available, the u function directs lsof to
read the device cache file at the default or
specified path, if possible, and to rebuild it,
if necessary. This is the default device cache
file function when no -D option has been speci-
fied. lsof repetitively from a shell script, for
example.
+|-f [cfgGn]
f by itself clarifies how path name arguments are
to be interpreted. When followed by c, f, g, G,
or n in any combination it specifies that the
listing of kernel file structure information 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 argu-
ments 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 inhibited, and is not available
Revision-4.49 6
LSOF(8)LSOF(8)
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 charac-
ters 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 output
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.
-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 termi-
nates 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
process.
When the field selection character list is empty,
all fields are selected and the NL field termina-
tor is used.
When the field selection character list contains
only a zero (`0'), all fields are selected and
the NUL terminator character is used.
Other combinations of fields and their associated
field terminator 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 - specification 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
Revision-4.49 7
LSOF(8)LSOF(8)
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 IDentifi-
cation (PGRP) numbers are in the comma-separated
set s - e.g., ``123'' or ``123,456''. (There
should be no spaces in the set.)
Multiple PGRP numbers are joined in a single ORed
set before participating in AND option selection.
The -g option also enables the output display of
PGRP numbers. When specified without a PGRP set
that's all it does.
-i [i] This option selects the listing of files any of
whose Internet address matches the address speci-
fied in i. If no address is specified, this
option selects the listing of all Internet and
x.25 (HP-UX) network files.
Multiple addresses (up to a limit of 100) may be
specified with multiple -i options. (A port num-
ber or service name range is counted as one
address.) They are joined in a single ORed set
before participating in AND option selection.
An Internet address is specified in the form:
[protocol][@hostname|hostaddr][:service|port]
where:
protocol is a protocol name - TCP or UDP.
hostname is an Internet host name.
hostaddr is a numeric Internet IPv4 address in
dot form; or an IPv6 numeric address in colon
form, enclosed in brackets.
service is an /etc/services name - e.g., smtp -
or list of them.
port is a port number, or list of them.
IPv6 numeric host addresses may be specified only
if the UNIX dialect supports them. To see if the
dialect supports IPv6 addresses, run lsof and
specify the -h or -? (help) option. If the dis-
played description of the -i option contains
``IPv[46]'', IPv6 addresses are supported.
At least one address component - protocol, host
specification, service or port specification -
must be supplied. The `@' character, leading the
host specification, is always required; as is the
Revision-4.49 8
LSOF(8)LSOF(8)
`:', leading the port specification. Specify
either hostname or hostaddr. Specify either ser-
vice name list or port number list. If a service
name list is specified, the protocol may also
need to be specified if the TCP and UDP port num-
bers for the service name are different. Use any
case - lower or upper - for protocol.
Service names and port numbers may be combined in
a list whose entries are separated by commas and
whose numeric range entries are separated by
minus signs. There may be no embedded spaces,
and all service names must belong to the speci-
fied protocol. Since service names may contain
embedded minus signs, the staring entry of a
range can't be a service name; it can be a port
number, however.
Here are some sample addresses:
TCP:25 - TCP and port 25
@1.2.3.4 - Internet IPv4 host address 1.2.3.4
@[3ffe:1ebc::1]:1234 - Internet IPv6 host address
3ffe:1ebc::1, port 1234
UDP:who - UDP who service port
TCP@vic.cc:513 - TCP, port 513 and host name vic.cc
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. This option is
not available under AIX on the IBM RISC/System
6000.
-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 sock-
ets, or most FIFOs and pipes.
When +L is specified without a following number,
all link counts will be listed. When -L is spec-
ified (the default), no link counts will be
listed.
When +L is followed by a number, only files hav-
ing a link count less than that number will be
Revision-4.49 9
LSOF(8)LSOF(8)
listed. (No number may follow -L.) A specifica-
tion of the form ``+L1'' will select open files
that have been unlinked. A specification of the
form ``+aL1 <file_system>'' will select unlinked
open files on the specified file system.
For other link count comparisons, use field out-
put (-F) and a post-processing script.
-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 registrations for local TCP and UDP
ports. The default reporting mode is set by the
lsof builder with the HASPMAPENABLED #define in
the dialect's machine.h header file; lsof is dis-
tributed with the HASPMAPENABLED #define deacti-
vated, so portmapper reporting is disabled by
default and must be requested with +M. Specify-
ing lsof's -h or -? option will report the
default mode. Disabling portmapper registration
when it is already disabled or enabling it when
already enabled is acceptable. in a warning.
When portmapper registration reporting is
enabled, lsof displays the portmapper registra-
tion (if any) for local TCP or UDP ports in
square brackets immediately following the port
numbers or service names - e.g., ``:1234[name]''
or ``:name[100083]''. The registration informa-
tion may be a name or number, depending on what
the registering program supplied to the portmap-
per when it registered the port.
When portmapper registration reporting is
enabled, lsof may run a little more slowly or
even become blocked when access to the portmapper
becomes congested or stopped. Reverse the
reporting mode to determine if portmapper regis-
tration reporting is slowing or blocking lsof.
For purposes of portmapper registration reporting
lsof considers a TCP or UDP port local if: it is
found in the local part of its containing kernel
structure; or if it is located in the foreign
part of its containing kernel structure and the
local and foreign Internet addresses are the
same; or if it is located in the foreign part of
its containing kernel structure and the foreign
Internet address is INADDR_LOOPBACK (127.0.0.1).
This rule may make lsof ignore some foreign ports
on machines with multiple interfaces when the
Revision-4.49 10
LSOF(8)LSOF(8)
foreign Internet address is on a different inter-
face from the local one.
See the 00FAQ file of the lsof distribution for
further discussion of portmapper registration
reporting issues.
-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. It causes the SIZE/OFF output col-
umn title to be changed to OFFSET.
The -o and -s options are mutually exclusive;
they can't both be specified. When neither is
specified, lsof displays whatever value - size or
offset - is appropriate and available for the
type of the file.
-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.
This option does NOT direct lsof to display off-
set at all times; specify -o (without a trailing
number) to do that. This option only specifies
the number of digits after ``0t'' in either mixed
size and offset or offset-only output. Thus, for
example, to direct lsof to display offset at all
times with a decimal digit count of 10, use:
-o -o 10
or
-oo10
The default number of digits allowed after ``0t''
is normally 8, but may have been changed by the
lsof builder. Consult the description of the -o
o option in the output of the -h or -? option to
determine the default that is in effect.
-O This option directs lsof to bypass the strategy
it uses to avoid being blocked by some kernel
operations - i.e., doing them in forked child
processes. See the BLOCKS AND TIMEOUTS and
AVOIDING KERNEL BLOCKS sections for more
Revision-4.49 11
LSOF(8)LSOF(8)
information on kernel operations that may block
lsof.
While use of this option will reduce lsof startup
overhead, it may also cause lsof to hang when the
kernel doesn't respond to a function. Use this
option cautiously.
-p s This option selects the listing of files for the
processes whose ID numbers are in the comma-sepa-
rated set s - e.g., ``123'' or ``123,456''.
(There should be no spaces in the set.)
Multiple process ID numbers are joined in a sin-
gle ORed set before participating in AND option
selection.
-P This option inhibits the conversion of port num-
bers 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 out-
put is in progress (the -F, option has been spec-
ified), the marker is `m'; otherwise the marker
is ``========''. The marker is followed by a NL
character.
Repeat mode reduces lsof startup overhead, so it
is more efficient to use this mode than to call
lsof repetitively from a shell script, for exam-
ple.
To use repeat mode most efficiently, accompany
Revision-4.49 12
LSOF(8)LSOF(8)
+|-r with specification 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.
-R This option directs lsof to list the Parent Pro-
cess 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; they can't
both be specified. When neither is specified,
lsof displays whatever value - size or offset -
is appropriate and available for the type of
file.
-S [t] This option specifies an optional time-out sec-
onds value for kernel functions - lstat(2), read-
link(2), and stat(2) - that might otherwise dead-
lock. The minimum for t is two; the default,
fifteen; when no value is specified, the default
is used.
See the BLOCKS AND TIMEOUTS section for more
information.
-T [t] This option controls the reporting of some
TCP/TPI information, also reported by netstat(1),
following the network addresses. In normal out-
put the information appears in parentheses, each
item except state identified by a keyword, fol-
lowed by `=', separated from others by a single
space:
<TCP or TPI state name>
QR=<read queue length>
QS=<send queue length>
WR=<window read length> (not all dialects)
WW=<window write length> (not all dialects)
When the field output mode is in effect (See OUT-
PUT FOR OTHER PROGRAMS.) each item appears as a
field with a `T' leading character, and the TCP
or TPI state name has the prefix ``ST=''.
Revision-4.49 13
LSOF(8)LSOF(8)-T with no following key characters disables
TCP/TPI information reporting.
-T with following characters selects the report-
ing of specific TCP/TPI information:
q selects queue length reporting.
s selects state reporting.
w selects window size reporting (not
all dialects).
State is reported by default. The -h or -? help
output for the -T option will show whether window
size reporting can be requested.
When -T is used to select information - i.e., it
is followed by one or more selection characters -
the displaying of state is disabled by default,
and it must be explicitly selected again in the
characters following -T. (In effect, then, the
default is equivalent to -Ts.) For example, if
queue lengths and state are desired, use -Tqs.
-t This option specifies that lsof should produce
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. A negated login name or user ID selec-
tion is neither ANDed nor ORed with other selec-
tions; it is applied before all other selections
and absolutely excludes the listing of the files
of the process. 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
Revision-4.49 14
LSOF(8)LSOF(8)lsof binary was constructed; 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 com-
piler 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, PGRPs, and UIDs.
When other options are ANDed to search options,
lsof may not report that it failed to find a
search item when an ANDed option prevents the
listing of the open file containing the located
search item. For example, ``lsof -V -iTCP@foobar
-a -d 999'' may not report a failure to locate
open files at ``TCP@foobar'' and may not list
any, if none have a file descriptor number of
999.
+|-w Enables (+) or disables (-) the suppression of
warning messages.
The lsof builder may choose to have warning mes-
sages disabled or enabled by default. The
default warning message state is indicated in the
output of the -h or -? option. Disabling warn-
ing messages when they are already disabled or
enabling them when already enabled is acceptable.
The -t option selects the -w option.
-X This is a dialect-specific option.
AIX:
WARNING: use of this option on a busy AIX system
might cause an application process to hang so
completely that it can neither be killed nor
stopped. I have never seen this happen or had a
report of it, but I think the possibility exists.
This IBM AIX RISC/System 6000 -X option directs
lsof to use the kernel readx() function. By
default use of readx() is disabled.
The lsof builder may specify that the -X option
be restricted to processes whose real UID is
root. If that has been done, the -X option will
not appear in the -h or -? help output unless
the real UID of the lsof process is root. The
default lsof distribution allows any UID to
Revision-4.49 15
LSOF(8)LSOF(8)
specify -X, so by default it will appear in the
help output.
When AIX readx() use is disabled, lsof may not be
able to report information for all text and
loader file references, but it may also avoid
exacerbating an AIX kernel directory search ker-
nel error, known as the Stale Segment ID bug.
When readx() is enabled, lsof will attempt to
report information on the text file being exe-
cuted by each process and the shared libraries it
uses.
The readx() function, used by lsof or any other
program, to access some sections of kernel vir-
tual memory, can trigger the Stale Segment ID
bug. It can cause the kernel's dir_search()
function erroneously to believe that part of an
in-memory copy of a file system directory has
been zeroed. Another application process, dis-
tinct from lsof, asking the kernel to search the
directory - e.g., by using open(2) - can cause
dir_search() to loop forever, thus hanging the
application process.
Consult the 00FAQ and 00README files of the lsof
distribution for a more complete description of
the Stale Segment ID bug, its APAR, and methods
for defining readx() use when compiling lsof.
PTX:
This Sequent PTX -X option directs lsof to list
the file use count and inode address from the
file structure. Its effect is equivalent to +fcf
with these exceptions: the NODE-ID column title
will be changed to INODE-ADDR; and the only value
listed in the INODE-ADDR column will be the ker-
nel inode structure address for files that use an
inode.
The file use count (decimal) indicates the number
of concurrent users of the file descriptor. The
kernel inode address (hexadecimal) is a value
sometimes useful when working with a malfunction-
ing system. (Also see the manual page for the
PTX crash(1) application.)
-- 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
Revision-4.49 16
LSOF(8)LSOF(8)
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 separated from the preceding
options with the ``--'' option.
If a name is the mounted-on directory of a file
system or the device of the file system, lsof
will list all the files open on the file system.
To be considered a file system, the name must
match a mounted-on directory name in mount(8)
output, or match the name of a block device asso-
ciated with a mounted-on directory name. The
+|-f option may be used to force lsof to consider
a name a file system identifier (+f) or a simple
file (-f).
If name is a path to a directory that is not the
mounted-on directory name of a file system, it is
treated just as a regular file is treated - i.e.,
its listing is restricted to processes that have
it open as a file or as a process-specific direc-
tory, such as the root or current working direc-
tory. To request that lsof look for open files
inside a directory name, use the +d s and +D D
options.
If a name is the base name of a family of multi-
plexed files - e. g, AIX's /dev/pt[cs] - lsof
will list all the associated multipled files on
the device that are open - e.g., /dev/pt[cs]/1,
/dev/pt[cs]/2, etc.
If a name is a UNIX domain socket name, lsof will
search for it by the characters of the name alone
- both as specified and as resolved from symbolic
links. When the socket uses a name that is a
symbolic link to another, you must specify the
name the socket uses. However, if the socket
uses the symbolic link's resolution, you may
specify it or the symbolic link origination.
When asking lsof to search for a UNIX domain
socket name, be careful to specify its absolute
path, just as it appears in kernel structures.
Specifying a relative path - e.g., ./file - in
place of the file's absolute path - e.g.,
/tmp/file - won't work because lsof must match
the characters you specify with what it finds in
the kernel structures associated with UNIX domain
sockets.
If a name is none of the above, lsof will list
Revision-4.49 17
LSOF(8)LSOF(8)
any open files whose device and inode match that
of the specified path name.
If you have also specified the -b option, the
only names you may safely specify are file sys-
tems for which your mount table supplies alter-
nate device numbers. See the AVOIDING KERNEL
BLOCKS and ALTERNATE DEVICE NUMBERS sections for
more information.
Multiple file names are joined in a single ORed
set before participating in AND option selection.
AFS
Lsof supports the recognition of AFS files for these
dialects (and AFS versions):
AIX 4.1.4 (AFS 3.4a)
HP-UX 9.0.5 (AFS 3.4a)
Linux 1.2.13 (AFS 3.3)
Solaris 2.[56] (AFS 3.4a)
SunOS 4.1.4 (AFS 3.3a)
Ultrix 4.2 RISC (AFS 3.2b)
It may recognize AFS files on other versions of these
dialects, but has not been tested there. Depending on how
AFS is implemented, lsof may recognize AFS files in other
dialects, or may have difficulties recognizing AFS files
in the supported dialects.
Lsof may have trouble identifying all aspects of AFS files
in supported dialects when AFS kernel support is imple-
mented via dynamic modules whose addresses do not appear
in the kernel's variable name list. In that case, lsof
may have to guess at the identity of AFS files, and might
not be able to obtain volume information from the kernel
that is needed for calculating AFS volume node numbers.
When lsof can't compute volume node numbers, it reports
blank in the NODE column.
The -A A option is available in some dialect implementa-
tions of lsof for specifying the name list file where
dynamic module kernel addresses may be found. When this
option is available, it will be listed in the lsof help
output, presented in response to the -h or -?
See the 00FAQ file of the lsof distribution for more
information about dynamic modules, their symbols, and how
they affect lsof options.
Because AFS path lookups don't seem to participate in the
kernel's name cache operations, lsof can't identify path
name components for AFS files.
Revision-4.49 18
LSOF(8)LSOF(8)SECURITY
Lsof has three features that may cause security concerns.
First, its default compilation mode allows anyone to list
all open files with it. Second, by default it creates a
user-readable and user-writable device cache file in the
home directory of the real user ID that executes lsof.
(The list-all-open-files and device cache features may be
disabled when lsof is compiled.) Third, its -k and -m
options name alternate kernel name list or memory files.
Restricting the listing of all open files is controlled by
the compile-time HASSECURITY option. When HASSECURITY is
defined, lsof will allow only the root user to list all
open files. The non-root user may list only open files of
processes with the same user IDentification number as the
real user ID number of the lsof process (the one that its
user logged on with). When HASSECURITY is not defined,
anyone may list all open files.
Help output, presented in response to the -h or -?
option, gives the HASSECURITY definition status.
See the Security section of the 0README file of the lsof
distribution for information on building lsof with the
HASSECURITY option enabled.
Creation and use of a user-readable and user-writable
device cache file is controlled by the compile-time HASD-
CACHE option. See the DEVICE CACHE FILE section and the
sections that follow it for details on how its path is
formed. For security considerations it is important to
note that in the default lsof distribution, if the real
user ID under which lsof is executed is root, the device
cache file will be written in root's home directory -
e.g., / or /root. When HASDCACHE is not defined, lsof
does not write or attempt to read a device cache file.
When HASDCACHE is defined, the lsof help output, presented
in response to the -h, -D?, or -? options, will provide
device cache file handling information. When HASDCACHE is
not defined, the -h or -? output will have no -D option
description.
Before you decide to disable the device cache file feature
- enabling it improves the performance of lsof by reducing
the startup overhead of examining all the nodes in /dev
(or /devices) - read the discussion of it in the 00DCACHE
and 00FAQ files of the lsof distribution.
WHEN IN DOUBT, YOU CAN TEMPORARILY DISABLE THE USE OF THE
DEVICE CACHE FILE WITH THE -Di OPTION.
When lsof user declares alternate kernel name list or mem-
ory files with the -k and -m options, lsof checks the
Revision-4.49 19
LSOF(8)LSOF(8)
user's authority to read them with access(2). This is
intended to prevent whatever special power lsof's modes
might confer on it from letting it read files not normally
accessible via the authority of the real user ID.
OUTPUT
This section describes the information lsof lists for each
open file. See the OUTPUT FOR OTHER PROGRAMS section for
additional information on output that can be processed by
another program.
Lsof only outputs printable ASCII characters. Non-print-
able characters are printed in one of three forms: the C
``\[bfrnt]'' form; the control character `^' form (e.g.,
``^@''); or hexadecimal leading ``\x'' form (e.g.,
``\xab''). Space is non-printable in the COMMAND column
(``\x20'') and printable elsewhere.
Lsof dynamically sizes the output columns each time it
runs, guaranteeing that each column is a minimum size. It
also guarantees that each column is separated from its
predecessor by at least one space.
COMMAND contains the first nine characters of the name
of the UNIX command associated with the pro-
cess.
All command name characters maintained by the
kernel in its structures are displayed in field
output when the command name descriptor (`c')
is specified. See the OUTPUT FOR OTHER COM-
MANDS section for information on selecting
field output and the associated command name
descriptor.
PID is the Process IDentification number of the
process.
PPID is the Parent Process IDentification number of
the process. It is only displayed when the -R
option has been specified.
PGRP is the process group IDentification number
associated with the process. It is only dis-
played when the -g option has been specified.
USER is the user ID number or login name of the user
to whom the process belongs, as reported by
ps(1). (See the -l option description.)
FD is the File Descriptor number of the file or:
cwd current working directory;
Lnn library references (AIX);
Revision-4.49 20
LSOF(8)LSOF(8)
ltx shared library text (code and data);
Mxx hex memory-mapped type number xx.
m86 DOS Merge mapped file;
mem memory-mapped file;
pd parent directory;
rtd root directory;
txt program text (code and data);
v86 VP/ix mapped file;
FD is followed by one of these characters,
describing the mode under which the file is
open:
r for read access;
w for write access;
u for read and write access;
space if unknown and no lock character;
`-' if unknown and lock character.
The mode character is followed by one of these
characters, describing the type of lock applied
to the file:
N for a Solaris NFS lock of unknown type;
r for read lock on part of the file;
R for a read lock on the entire file;
w for a write lock on part of the file;
W for a write lock on the entire file;
u for a read and write lock of any length;
U for a lock of unknown type;
x for an SCO OpenServer Xenix lock on part
of the file;
X for an SCO OpenServer Xenix lock on the
entire file;
space if there is no lock.
See the LOCKS section for more information on
the lock information character.
The FD column is parsable as a single field.
TYPE is the type of the node associated with the
file - e.g., GDIR, GREG, VDIR, VREG, etc.
or ``IPv4'' for an IP version 4 socket;
or ``IPv6'' for an IP version 6 socket;
or ``ax25'' for a Linux AX.25 socket;
or ``dnet'' for a DECnet socket;
or ``inet'' for an Internet domain socket;
Revision-4.49 21
LSOF(8)LSOF(8)
or ``lla'' for a HP-UX link level access file;
or ``rte'' for an AF_ROUTE socket;
or ``sock'' for a socket of unknown domain;
or ``unix'' for a UNIX domain socket;
or ``x.25'' for an HP-UX x.25 socket;
or ``BLK'' for a block special file;
or ``CHR'' for a character special file;
or ``DIR'' for a directory;
or ``DOOR'' for a VDOOR file;
or ``FIFO'' for a FIFO special file;
or ``LINK'' for a symbolic link file;
or ``MPB'' for a multiplexed block file;
or ``MPC'' for a multiplexed character file;
or ``PAS'' for a /proc/as file;
or ``PAXV'' for a /proc/auxv file;
or ``PCRE'' for a /proc/cred file;
or ``PCTL'' for a /proc control file;
or ``PCUR'' for the current /proc process;
or ``PCWD'' for a /proc current working direc-
tory;
or ``PDIR'' for a /proc directory;
or ``PETY'' for a /proc executable type
(etype);
or ``PFD'' for a /proc file descriptor;
or ``PFDR'' for a /proc file descriptor direc-
tory;
or ``PFIL'' for an executable /proc file;
or ``PFPR'' for a /proc FP register set;
or ``PGD'' for a /proc/pagedata file;
Revision-4.49 22
LSOF(8)LSOF(8)
or ``PGRP'' for a /proc group notifier file;
or ``PIPE'' for pipes;
or ``PLC'' for a /proc/lwpctl file;
or ``PLDR'' for a /proc/lpw directory;
or ``PLDT'' for a /proc/ldt file;
or ``PLPI'' for a /proc/lpsinfo file;
or ``PLST'' for a /proc/lstatus file;
or ``PLU'' for a /proc/lusage file;
or ``PLWG'' for a /proc/gwindows file;
or ``PLWI'' for a /proc/lwpsinfo file;
or ``PLWS'' for a /proc/lwpstatus file;
or ``PLWU'' for a /proc/lwpusage file;
or ``PLWX'' for a /proc/xregs file'
or ``PMAP'' for a /proc map file (map);
or ``PMEM'' for a /proc memory image file;
or ``PNTF'' for a /proc process notifier file;
or ``POBJ'' for a /proc/object file;
or ``PODR'' for a /proc/object directory;
or ``POLP'' for an old format /proc light
weight process file;
or ``POPF'' for an old format /proc PID file;
or ``POPG'' for an old format /proc page data
file;
or ``PORT'' for an Ultrix SYSV named pipe;
or ``PREG'' for a /proc register file;
or ``PRMP'' for a /proc/rmap file;
or ``PRTD'' for a /proc root directory;
or ``PSGA'' for a /proc/sigact file;
Revision-4.49 23
LSOF(8)LSOF(8)
or ``PSIN'' for a /proc/psinfo file;
or ``PSTA'' for a /proc status file;
or ``PUSG'' for a /proc/usage file;
or ``PW'' for a /proc/watch file;
or ``PXMP'' for a /proc/xmap file;
or ``REG'' for a regular file;
or ``SMT'' for a shared memory transport file;
or ``STSO'' for a stream socket;
or ``UNNM'' for an unnamed type file.
FILE-ADDR contains the kernel file structure address when
f has been specified to +f;
FCT contains the shared use count from the kernel
file structure when c has been specified to +f;
FILE-FLAG when g or G has been specified to +f, this
field contains the contents of the f_flag[s]
member of the kernel file structure and the
kernel's per-process open file flags (if avail-
able); `G' causes them to be displayed in hex-
adecimal; `g', as short-hand names; two lists
may be displayed with entries separated by com-
mas, the lists separated by a semicolon (`;');
the first list may contain short-hand names for
f_flag[s] values from the following table:
AIO asynchronous I/O (e.g., FAIO)
AP append
ASYN asynchronous I/O (e.g., FASYNC)
BAS block, test, and set in use
BKIU block if in use
BL use block offsets
BSK block seek
CA copy avoid
CLON clone
CLRD CL read
CR create
DF defer
DFI defer IND
DFLU data flush
DIR direct
DLY delay
DOCL do clone
DSYN data-only integrity
EX open for exec
Revision-4.49 24
LSOF(8)LSOF(8)
EXCL exclusive open
FSYN synchronous writes
GCDF defer during unp_gc() (AIX)
GCMK mark during unp_gc() (AIX)
GTTY accessed via /dev/tty
HUP HUP in progress
KERN kernel
KIOC kernel-issued ioctl
LCK has lock
LG large file
MBLK stream message block
MK mark
MNT mount
MSYN multiplex synchronization
NB non-blocking I/O
NBDR no BDRM check
NBIO SYSV non-blocking I/O
NBF n-buffering in effect
NC no cache
ND no delay
NDSY no data synchronization
NET network
NMFS NM file system
NOTO disable background stop
NSH no share
NTTY no controlling TTY
OLRM OLR mirror
PAIO POSIX asynchronous I/O
PP POSIX pipe
R read
RAIO Reliant UNIX RAIO request
RC file and record locking cache
REV revoked
RSH shared read
RSYN read synchronization
SL shared lock
SOCK socket
SQSH Sequent shared set on open
SQSV Sequent SVM set on open
SQR Sequent set repair on open
SQS1 Sequent full shared open
SQS2 Sequent partial shared open
STPI stop I/O
SWR synchronous read
SYN file integrity while writing
TCPM avoid TCP collision
TR truncate
W write
WKUP parallel I/O synchronization
WTG parallel I/O synchronization
VH vhangup pending
VTXT virtual text
XL exclusive lock
Revision-4.49 25
LSOF(8)LSOF(8)
this list of names was derived from F*
#define's in dialect header files <fcntl.h>,
<linux</fs.h>, sys/fcntl.c>, <sys/fcntlcom.h>,
and <sys/file.h>; see the lsof.h header file
for a list showing the correspondence between
the above short-hand names and the header file
definitions;
the second list (after the semicolon) may con-
tain short-hand names for kernel per-process
open file flags from this table:
ALLC allocated
BR the file has been read
BHUP activity stopped by SIGHUP
BW the file has been written
CLSG closing
CX close-on-exec (see fcntl(F_SETFD))
MP memory-mapped
LCK lock was applied
RSVW reserved wait
SHMT UF_FSHMAT set (AIX)
USE in use (multi-threaded)
NODE-ID (or INODE-ADDR for some dialects) contains a
unique identifier for the file node (usually
the kernel vnode or inode address, but also
occasionally a concatenation of device and node
number) when n has been specified to +f;
DEVICE contains the device numbers, separated by com-
mas, for a character special, block special,
regular, directory or NFS file;
or the protocol control block address of a DEC-
net (Ultrix 4.2), Internet, UNIX, or x.25
(HP-UX) network file - the address that appears
in the -A output from some netstat(1) programs;
or ``memory'' for a memory file system node
under DEC OSF/1, Digital UNIX, or Tru64 UNIX;
or the address of the private data area of a
Solaris socket stream;
or a kernel reference address that identifies
the file (The kernel reference address may be
used for FIFO's, for example.);
or the base address or device name of a Linux
AX.25 socket device.
Usually only the lower thirty two bits of DEC
OSF/1, Digital UNIX, or Tru64 UNIX kernel
Revision-4.49 26
LSOF(8)LSOF(8)
addresses are displayed.
SIZE, SIZE/OFF, or OFFSET
is the size of the file or the file offset in
bytes. A value is displayed in this column
only if it is available. Lsof displays what-
ever value - size or offset - is appropriate
for the type of the file and the version of
lsof.
The file size is displayed in decimal; the off-
set is normally displayed in decimal with a
leading ``0t'' if it contains 8 digits or less;
in hexadecimal with a leading ``0x'' if it is
longer than 8 digits. (Consult the -o o option
description for information on when 8 might
default to some other value.)
Thus the leading ``0t'' and ``0x'' identify an
offset when the column may contain both a size
and an offset (i.e., its title is SIZE/OFF).
If the -o option is specified, lsof always dis-
plays the file offset (or nothing if no offset
is available) and labels the column OFFSET.
The offset always begins with ``0t'' or ``0x''
as described above.
The lsof user can control the switch from
``0t'' to ``0x'' with the -o o option. Consult
its description for more information.
If the -s option is specified, lsof always dis-
plays the file size (or nothing if no size is
available) and labels the column SIZE. The -o
and -s options are mutually exclusive; they
can't both be specified.
For files that don't have a fixed size - e.g.,
don't reside on a disk device - lsof will dis-
play appropriate information about the current
size or position of the file if it is available
in the kernel structures that define the file.
NODE is the node number of a local file;
or the inode number of an NFS file in the
server host;
or the Internet protocol type - e. g, ``TCP'';
or ``STR'' for a stream;
or ``CCITT'' for an HP-UX x.25 socket;
Revision-4.49 27
LSOF(8)LSOF(8)
or the IRQ or inode number of a Linux AX.25
socket device.
NAME is the name of the mount point and file system
on which the file resides;
or the name of a file specified in the names
option (after any symbolic links have been
resolved);
or the name of a character special or block
special device;
or the local and remote Internet addresses of a
network file (as numbers or names, depending on
the -n and -P options); a UDP destination
Internet address may be followed by the amount
of time elapsed since the last packet was sent
to the destination; TCP and UDP destination
Internet addresses may be followed by TCP/TPI
information in parentheses - state (e.g.,
``(ESTABLISHED)'', ``(SS_ISCONNECTED)'',
``(TS_IDLE)'', ``(Unbound)''), queue sizes, and
window sizes (not all dialects) - in a fashion
similar to what netstat(1) reports; see the -T
option description or the description of the
TCP/TPI field in OUTPUT FOR OTHER PROGRAMS for
more information on state, queue size, and win-
dow size;
or the local and remote node and object
addresses of a DECnet file (The node address
appears as an area.node number pair if the -n
option is specified.);
or the address or name of a UNIX domain socket,
possibly including a stream clone device name,
a file system object's path name, local and
foreign kernel addresses, socket pair informa-
tion, and a bound vnode address;
or the local and remote mount point names of an
NFS file;
or ``STR'', followed by the stream name;
or a stream character device name, followed by
``->'' and the stream name;
or ``STR:'' followed by the SCO OpenServer
stream device and module names, separated by
``->'';
or the SunOS current working or root directory
Revision-4.49 28
LSOF(8)LSOF(8)
path name;
or system directory name, `` -- '', and as many
components of the path name as lsof can find in
the kernel's name cache for selected dialects
(See the KERNEL NAME CACHE section for more
information.);
or ``PIPE->'', followed by a Solaris kernel
pipe destination address;
or ``COMMON:'', followed by the vnode device
information structure's device name, for a
Solaris common vnode;
or the address family, followed by a slash
(`/'), followed by fourteen comma-separated
bytes of a non-Internet raw socket address;
or the HP-UX x.25 local address, followed by
the virtual connection number (if any), fol-
lowed by the remote address (if any);
or ``(dead)'' for disassociated DEC OSF/1, Dig-
ital UNIX, or Tru64 UNIX files - typically ter-
minal files that have been flagged with the
TIOCNOTTY ioctl and closed by daemons;
or ``rd=<offset>'' and ``wr=<offset>'' for the
values of the read and write offsets of a FIFO;
or ``clone n:/dev/event'' for SCO OpenServer
file clones of the /dev/event device, where n
is the minor device number of the file;
or ``(socketpair: n)'' for a Solaris 2.6, 7, 8
BETA, or 8 BETA-Refresh UNIX domain socket,
created by the socketpair(3N) network function;
or ``no PCB'' for AIX socket files that do not
have a protocol block associated with them,
optionally followed by ``, CANTSENDMORE'' if
sending on the socket has been disabled, or ``,
CANTRCVMORE'' if receiving on the socket has
been disabled (e.g., by the shutdown(2) func-
tion);
or the local and remote addresses of a Linux
IPX socket file in the form
<net>:[<node>:]<port>, followed in parentheses
by the transmit and receive queue sizes, and
the connection state.
For dialects that support a ``namefs'' file system,
Revision-4.49 29
LSOF(8)LSOF(8)
allowing one file to be attached to another with fat-
tach(3C), lsof will add ``(FA:<address1><direc-
tion><address2>)'' to the NAME column. <address1> and
<address2> are hexadecimal vnode addresses. <direction>
will be ``<-'' if <address2> has been fattach'ed to this
vnode whose address is <address1>; and ``->'' if
<address1>, the vnode address of this vnode, has been fat-
tach'ed to <address2>. <address1> may be omitted if it
already appears in the DEVICE column.
LOCKS
Lsof can't adequately report the wide variety of UNIX
dialect file locks in a single character. What it reports
in a single character is a compromise between the informa-
tion it finds in the kernel and the limitations of the
reporting format.
Moreover, when a process holds several byte level locks on
a file, lsof only reports the status of the first lock it
encounters. If it is a byte level lock, then the lock
character will be reported in lower case - i.e., `r', `w',
or `x' - rather than the upper case equivalent reported
for a full file lock.
Generally lsof can only report on locks held by local pro-
cesses on local files. When a local process sets a lock
on a remotely mounted (e.g., NFS) file, the remote server
host usually records the lock state. One exception is
Solaris - at some patch levels of 2.3, and in all versions
above 2.4, the Solaris kernel records information on
remote locks in local structures.
Lsof has trouble reporting locks for some UNIX dialects.
Consult the BUGS section of this file or the 00FAQ file of
the lsof distribution for more information.
OUTPUT FOR OTHER PROGRAMS
When the -F option is specified, lsof produces output that
is suitable for processing by another program - e.g, an
awk or Perl script.
Each unit of information is output in a field that is
identified with a leading character and terminated by a NL
(012) (or a NUL (000) if the 0 (zero) field identifier
character is specified.) The data of the field follows
immediately after the field identification character and
extends to the field terminator.
It is possible to think of field output as process and
file sets. A process set begins with a field whose iden-
tifier is `p' (for process IDentifier (PID)). It extends
to the beginning of the next PID field or the beginning of
the first file set of the process, whichever comes first.
Included in the process set are fields that identify the
Revision-4.49 30
LSOF(8)LSOF(8)
command, the process group IDentification (PGRP) number,
and the user ID (UID) number or login name.
A file set begins with a field whose identifier is `f'
(for file descriptor). It is followed by lines that
describe the file's access mode, lock state, type, device,
size, offset, inode, protocol, name and stream module
names. It extends to the beginning of the next file or
process set, whichever comes first.
When the NUL (000) field terminator has been selected with
the 0 (zero) field identifier character, lsof ends each
process and file set with a NL (012) character.
Lsof always produces one field, the PID (`p') field. All
other fields may be declared optionally in the field iden-
tifier character list that follows the -F option. 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.
It is entirely possible to select a set of fields that
cannot easily be parsed - e.g., if the field descriptor
field is not selected, it may be difficult to identify
file sets. To help you avoid this difficulty, lsof sup-
ports the -F option; it selects the output of all fields
with NL terminators (the -F0 option pair selects the out-
put of all fields with NUL terminators).
These are the fields that lsof will produce. The single
character listed first is the field identifier.
a file access mode
c process command name (all characters from proc or
user structure)
C file structure share count
d file's device character code
D file's major/minor device number (0x<hexadecimal>)
f file descriptor
F file structure address (0x<hexadecimal>)
G file flaGs (0x<hexadecimal>; names if +fg follows)
i file's inode number
l file's lock status
L process login name
m marker between repeated output
n file name, comment, Internet address
N node identifier (ox<hexadecimal>
o file's offset (decimal)
p process ID (always selected)
g process group ID
P protocol name
R parent process ID
s file's size (decimal)
Revision-4.49 31
LSOF(8)LSOF(8)
S file's stream identification
t file's type
T TCP/TPI information, identified by prefixes (the
`=' is part of the prefix):
ST=<state>
QR=<read queue size>
QS=<write queue size>
WR=<window read size> (not all dialects)
WW=<window write size> (not all dialects)
(TPI state information and window sizes aren't
reported for all supported UNIX dialects. The
-h or -? help output for the -T option will
show whether window size reporting can be
requested.)
u process user ID
0 use NUL field terminator character in place of NL
1-9 dialect-specific field identifiers (The output
of -F? identifies the information to be found
in dialect-specific fields.)
You can get on-line help information on these characters
and their descriptions by specifying the -F? option pair.
(Escape the `?' character as your shell requires.) Addi-
tional information on field content can be found in the
OUTPUT section.
As an example, ``-F pcfn'' will select the process ID
(`p'), command name (`c'), file descriptor (`f') and file
name (`n') fields with an NL field terminator character;
``-F pcfn0'' selects the same output with a NUL (000)
field terminator character.
Lsof doesn't produce all fields for every process or file
set, only those that are available. Some fields are mutu-
ally exclusive: file device characters and file
major/minor device numbers; file inode number and protocol
name; file name and stream identification; file size and
offset. One or the other member of these mutually exclu-
sive sets will appear in field output, but not both.
Normally lsof ends each field with a NL (012) character.
The 0 (zero) field identifier character may be specified
to change the field terminator character to a NUL (000).
A NUL terminator may be easier to process with xargs (1),
for example, or with programs whose quoting mechanisms may
not easily cope with the range of characters in the field
output. When the NUL field terminator is in use, lsof
ends each process and file set with a NL (012).
Two aids to producing programs that can process lsof field
output are included in the lsof distribution. The first
is a C header file, lsof_fields.h, that contains symbols
for the field identification characters, indexes for stor-
ing them in a table, and explanation strings that may be
Revision-4.49 32
LSOF(8)LSOF(8)
compiled into programs. Lsof uses this header file.
The second aid is a set of sample scripts that process
field output, written in awk, Perl 4, and Perl 5. They're
located in the scripts subdirectory of the lsof distribu-
tion.
BLOCKS AND TIMEOUTS
Lsof can be blocked by some kernel functions that it uses
- lstat(2), readlink(2), and stat(2). These functions are
stalled in the kernel, for example, when the hosts where
mounted NFS file systems reside become inaccessible.
Lsof attempts to break these blocks with timers and child
processes, but the techniques are not wholly reliable.
When lsof does manage to break a block, it will report the
break with an error message. The messages may be sup-
pressed with the -t and -w options.
The default timeout value may be displayed with the -h or
-? option, and it may be changed with the -S [t] option.
The minimum for t is two seconds, but you should avoid
small values, since slow system responsiveness can cause
short timeouts to expire unexpectedly and perhaps stop
lsof before it can produce any output.
When lsof has to break a block during its access of
mounted file system information, it normally continues,
although with less information available to display about
open files.
Lsof can also be directed to avoid the protection of
timers and child processes when using the kernel functions
that might block by specifying the -O option. While this
will allow lsof to start up with less overhead, it exposes
lsof completely to the kernel situations that might block
it. Use this option cautiously.
AVOIDING KERNEL BLOCKS
You can use the -b option to tell lsof to avoid using ker-
nel functions that would block. Some cautions apply.
First, using this option usually requires that your system
supply alternate device numbers in place of the device
numbers that lsof would normally obtain with the lstat(2)
and stat(2) kernel functions. See the ALTERNATE DEVICE
NUMBERS section for more information on alternate device
numbers.
Second, you can't specify names for lsof to locate unless
they're file system names. This is because lsof needs to
know the device and inode numbers of files listed with
names in the lsof options, and the -b option prevents lsof
from obtaining them. Moreover, since lsof only has device
Revision-4.49 33
LSOF(8)LSOF(8)
numbers for the file systems that have alternates, its
ability to locate files on file systems depends completely
on the availability and accuracy of the alternates. If no
alternates are available, or if they're incorrect, lsof
won't be able to locate files on the named file systems.
Third, if the names of your file system directories that
lsof obtains from your system's mount table are symbolic
links, lsof won't be able to resolve the links. This is
because the -b option causes lsof to avoid the kernel
readlink(2) function it uses to resolve symbolic links.
Finally, using the -b option causes lsof to issue warning
messages when it needs to use the kernel functions that
the -b option directs it to avoid. You can suppress these
messages by specifying the -w option, but if you do, you
won't see the alternate device numbers reported in the
warning messages.
ALTERNATE DEVICE NUMBERS
On some dialects, when lsof has to break a block because
it can't get information about a mounted file system via
the lstat(2) and stat(2) kernel functions, or because you
specified the -b option, lsof can obtain some of the
information it needs - the device number and possibly the
file system type - from the system mount table. When that
is possible, lsof will report the device number it
obtained. (You can suppress the report by specifying the
-w option.)
You can assist this process if your mount table is sup-
ported with an /etc/mtab or /etc/mnttab file that contains
an options field by adding a ``dev=xxxx'' field for mount
points that do not have one in their options strings.
The ``xxxx'' portion of the field is the hexadecimal value
of the file system's device number. (Consult the st_dev
field of the output of the lstat(2) and stat(2) functions
for the appropriate values for your file systems.) Here's
an example from a Sun Solaris 2.6 /etc/mnttab for a file
system remotely mounted via NFS:
nfs ignore,noquota,dev=2a40001
There's an advantage to having ``dev=xxxx'' entries in
your mount table file, especially for file systems that
are mounted from remote NFS servers. When a remote server
crashes and you want to identify its users by running lsof
on one of its clients, lsof probably won't be able to get
output from the lstat(2) and stat(2) functions for the
file system. If it can obtain the file system's device
number from the mount table, it will be able to display
the files open on the crashed NFS server.
Revision-4.49 34
LSOF(8)LSOF(8)
Some dialects that do not use an ASCII /etc/mtab or
/etc/mnttab file for the mount table may still provide an
alternative device number in their internal mount tables.
This includes AIX, DEC OSF/1, Digital UNIX, FreeBSD,
NetBSD, OpenBSD, Tru64 UNIX, and Ultrix. Lsof knows how
to obtain the alternative device number for these dialects
and uses it when its attempt to lstat(2) or stat(2) the
file system is blocked.
If you're not sure your dialect supplies alternate device
numbers for file systems from its mount table, use this
lsof incantation to see if it reports any alternate device
numbers:
lsof-b
Look for standard error file warning messages that begin
``assuming "dev=xxxx" from ...''.
KERNEL NAME CACHE
Lsof is able to examine the kernel's name cache or use
other kernel facilities (e.g., the ADVFS 4.x or higher
tag_to_path() function under Digital UNIX or Tru64 UNIX)
on some dialects for most file system types, excluding
AFS, and extract recently used path name components from
it. (AFS file system path lookups don't use the kernel's
name cache.)
Lsof reports the complete paths it finds in the NAME col-
umn. If lsof can't report all components in a path, it
reports in the NAME column the file system name, followed
by a space, two `-' characters, another space, and the
name components it has located, separated by the `/' char-
acter.
When lsof is run in repeat mode - i.e., with the -r option
specified - the extent to which it can report path name
components for the same file may vary from cycle to cycle.
That's because other running processes can cause the ker-
nel to remove entries from its name cache and replace them
with others.
Lsof's use of the kernel name cache to identify the paths
of files can lead it to report incorrect components under
some circumstances. This can happen when the kernel name
cache uses device and node number as a key (e.g., Linux
and SCO OpenServer) and a key on a rapidly changing file
system is reused. If the UNIX dialect's kernel doesn't
purge the name cache entry for a file when it is unlinked,
lsof may find a reference to the wrong entry in the cache.
The 00FAQ file of the lsof distribution has more informa-
tion on this situation.
Revision-4.49 35
LSOF(8)LSOF(8)
Lsof can report path name components for these dialects:
BSDI BSD/OS
DC/OSx
DEC OSF/1, Digital UNIX, Tru64 UNIX
FreeBSD
HP-UX
Linux
NetBSD
NEXTSTEP
OpenBSD
PTX
Reliant UNIX
SCO OpenServer
SCO UnixWare
Solaris
SunOS
Ultrix
Lsof can't report path name components for these dialects:
AIX
If you want to know why lsof can't report path name compo-
nents for some dialects, see the 00FAQ file of the lsof
distribution.
DEVICE CACHE FILE
Examining all members of the /dev (or /devices) node tree
with stat(2) functions can be time consuming. What's
more, the information that lsof needs - device number,
inode number, and path - rarely changes.
Consequently, lsof normally maintains an ASCII text file
of cached /dev (or /devices) information (exception: the
/proc-based Linux lsof where it's not needed.) The local
system administrator who builds lsof can control the way
the device cache file path is formed, selecting from these
options:
Path from the -D option;
Path from an environment variable;
System-wide path;
Personal path (the default);
Personal path, modified by an environment variable.
Consult the output of the -h, -D? , or -? help options
for the current state of device cache support. The help
output lists the default read-mode device cache file path
that is in effect for the current invocation of lsof. The
-D? option output lists the read-only and write device
cache file paths, the names of any applicable environment
variables, and the personal device cache path format.
Revision-4.49 36
LSOF(8)LSOF(8)
Lsof can detect that the current device cache file has
been accidentally or maliciously modified by integrity
checks, including the computation and verification of a
sixteen bit Cyclic Redundancy Check (CRC) sum on the
file's contents. When lsof senses something wrong with
the file, it issues a warning and attempts to remove the
current cache file and create a new copy, but only to a
path that the process can legitimately write.
The path from which a lsof process may attempt to read a
device cache file may not be the same as the path to which
it can legitimately write. Thus when lsof senses that it
needs to update the device cache file, it may choose a
different path for writing it from the path from which it
read an incorrect or outdated version.
If available, the -Dr option will inhibit the writing of a
new device cache file. (It's always available when speci-
fied without a path name argument.)
When a new device is added to the system, the device cache
file may need to be recreated. Since lsof compares the
mtime of the device cache file with the mtime and ctime of
the /dev (or /devices) directory, it usually detects that
a new device has been added; in that case lsof issues a
warning message and attempts to rebuild the device cache
file.
Whenever lsof writes a device cache file, it sets its own-
ership to the real UID of the executing process, and its
permission modes to 0600, this restricting its reading and
writing to the file's owner.
LSOF PERMISSIONS THAT AFFECT DEVICE CACHE FILE ACCESS
Two permissions of the lsof executable affect its ability
to access device cache files. The permissions are set by
the local system administrator when lsof is installed.
The first and rarer permission is setuid-root. It comes
into effect when lsof is executed; its effective UID is
then root, while its real (i.e., that of the logged-on
user) UID is not. The lsof distribution recommends that
versions for these dialects run setuid-root.
DC/OSx 1.1 for Pyramid systems
Reliant UNIX 5.4[34] for Pyramid systems
The second and more common permission is setgid. It comes
into effect when the effective group IDentification number
(GID) of the lsof process is set to one that can access
kernel memory devices - e.g., ``kmem'', ``sys'', or ``sys-
tem''.
An lsof process that has setgid permission usually
Revision-4.49 37
LSOF(8)LSOF(8)
surrenders the permission after it has accessed the kernel
memory devices. When it does that, lsof can allow more
liberal device cache path formations. The lsof distribu-
tion recommends that versions for these dialects run set-
gid and be allowed to surrender setgid permission.
AIX 4.1.[45], 4.2[.1], and 4.3[.123]
BSDI BSD/OS 2.1, 3.[01], and 4.[01] for Intel-based systems
DEC OSF/1, Digital UNIX, Tru64 UNIX 2.0, 3.2, 4.0, and 5.0
FreeBSD 2.1.[67], 2.2[.x], 3.[012], 4.0, and 5.0 for Intel-
based systems
HP-UX 9.01, 10.20, and 11.00
Linux 2.0.3[2346] for Intel-based systems
NetBSD 1.[234] for Intel and SPARC-based systems
NEXTSTEP 3.[13] for NEXTSTEP architectures
OpenBSD 2.[0123456] for Intel-based systems
RISC/os 4.52 for MIPS R2000-based systems
SCO OpenServer Release 3.0 and 5.0.[0245] for Intel-based
systems
SCO UnixWare 2.1.[123] and 7[[.0].1] for Intel-based systems
Sequent PTX 2.1.9, 4.2.[13], 4.[34], and 4.4.[12]
Solaris 2.5, 2.5.1, and 2.[67]
SunOS 4.1.x
Ultrix 4.2
Lsof for these dialects does not support a device cache,
so the permissions given to the executable don't apply to
the device cache file.
Linux 2.1.72 and above (/proc-based lsof)
DEVICE CACHE FILE PATH FROM THE -D OPTION
The -D option provides limited means for specifying the
device cache file path. Its ? function will report the
read-only and write device cache file paths that lsof will
use.
When the -D b, r, and u functions are available, you can
use them to request that the cache file be built in a spe-
cific location (b[path]); read but not rebuilt (r[path]);
or read and rebuilt (u[path]). The b, r, and u functions
are restricted under some conditions. They are restricted
when the lsof process is setuid-root. The path specified
with the r function is always read-only, even when it is
available.
The b, r, and u functions are also restricted when the
lsof process runs setgid and lsof doesn't surrender the
setgid permission. (See the LSOF PERMISSIONS THAT AFFECT
DEVICE CACHE FILE ACCESS section for a list of implementa-
tions that normally don't surrender their setgid permis-
sion.)
A further -D function, i (for ignore), is always
Revision-4.49 38
LSOF(8)LSOF(8)
available.
When available, the b function tells lsof to read device
information from the kernel with the stat(2) function and
build a device cache file at the indicated path.
When available, the r function tells lsof to read the
device cache file, but not update it. When a path argu-
ment accompanies -Dr, it names the device cache file path.
The r function is always available when it is specified
without a path name argument. If lsof is not running
setuid-root and surrenders its setgid permission, a path
name argument may accompany the r function.
When available, the u function tells lsof to attempt to
read and use the device cache file. If it can't read the
file, or if it finds the contents of the file incorrect or
outdated, it will read information from the kernel, and
attempt to write an updated version of the device cache
file, but only to a path it considers legitimate for the
lsof process effective and real UIDs.
DEVICE CACHE PATH FROM AN ENVIRONMENT VARIABLE
Lsof's second choice for the device cache file is the con-
tents of the LSOFDEVCACHE environment variable. It avoids
this choice if the lsof process is setuid-root, or the
real UID of the process is root.
A further restriction applies to a device cache file path
taken from the LSOFDEVCACHE environment variable: lsof
will not write a device cache file to the path if the lsof
process doesn't surrender its setgid permission. (See the
LSOF PERMISSIONS THAT AFFECT DEVICE CACHE FILE ACCESS sec-
tion for information on implementations that don't surren-
der their setgid permission.)
The local system administrator can disable the use of the
LSOFDEVCACHE environment variable or change its name when
building lsof. Consult the output of -D? for the envi-
ronment variable's name.
SYSTEM-WIDE DEVICE CACHE PATH
The local system administrator may choose to have a sys-
tem-wide device cache file when building lsof. That file
will generally be constructed by a special system adminis-
tration procedure when the system is booted or when the
contents of /dev or /devices) changes. If defined, it is
lsof's third device cache file path choice.
You can tell that a system-wide device cache file is in
effect for your local installation by examining the lsof
help option output - i.e., the output from the -h or -?
option.
Revision-4.49 39
LSOF(8)LSOF(8)
Lsof will never write to the system-wide device cache file
path by default. It must be explicitly named with a -D
function in a root-owned procedure. Once the file has
been written, the procedure must change its permission
modes to 0644 (owner-read and owner-write, group-read, and
other-read).
PERSONAL DEVICE CACHE PATH (DEFAULT)
The default device cache file path of the lsof distribu-
tion is one recorded in the home directory of the real UID
that executes lsof. Added to the home directory is a sec-
ond path component of the form .lsof_hostname.
This is lsof's fourth device cache file path choice, and
is usually the default. If a system-wide device cache
file path was defined when lsof was built, this fourth
choice will be applied when lsof can't find the sys-
tem-wide device cache file. This is the only time lsof
uses two paths when reading the device cache file.
The hostname part of the second component is the base name
of the executing host, as returned by gethostname(2). The
base name is defined to be the characters preceding the
first `.' in the gethostname(2) output, or all the geth-
ostname(2) output if it contains no `.'.
The device cache file belongs to the user ID and is read-
able and writable by the user ID alone - i.e., its modes
are 0600. Each distinct real user ID on a given host that
executes lsof has a distinct device cache file. The host-
name part of the path distinguishes device cache files in
an NFS-mounted home directory into which device cache
files are written from several different hosts.
The personal device cache file path formed by this method
represents a device cache file that lsof will attempt to
read, and will attempt to write should it not exist or
should its contents be incorrect or outdated.
The -Dr option without a path name argument will inhibit
the writing of a new device cache file.
The -D? option will list the format specification for
constructing the personal device cache file. The conver-
sions used in the format specification are described in
the 00DCACHE file of the lsof distribution.
MODIFIED PERSONAL DEVICE CACHE PATH
If this option is defined by the local system administra-
tor when lsof is built, the LSOFPERSDCPATH environment
variable contents may be used to add a component of the
personal device cache file path.
The LSOFPERSDCPATH variable contents are inserted in the
Revision-4.49 40
LSOF(8)LSOF(8)
path at the place marked by the local system administrator
with the ``%p'' conversion in the HASPERSDC format speci-
fication of the dialect's machine.h header file. (It's
placed right after the home directory in the default lsof
distribution.)
Thus, for example, if LSOFPERSDCPATH contains ``LSOF'',
the home directory is ``/Homes/abe'', the host name is
``vic.cc.purdue.edu'', and the HASPERSDC format is the
default (``%h/%p.lsof_%L''), the modified personal device
cache file path is:
/Homes/abe/LSOF/.lsof_vic
The LSOFPERSDCPATH environment variable is ignored when
the lsof process is setuid-root or when the real UID of
the process is root.
Lsof will not write to a modified personal device cache
file path if the lsof process doesn't surrender setgid
permission. (See the LSOF PERMISSIONS THAT AFFECT DEVICE
CACHE FILE ACCESS section for a list of implementations
that normally don't surrender their setgid permission.)
If, for example, you want to create a sub-directory of
personal device cache file paths by using the LSOFPERSDC-
PATH environment variable to name it, and lsof doesn't
surrender its setgid permission, you will have to allow
lsof to create device cache files at the standard personal
path and move them to your subdirectory with shell com-
mands.
The local system administrator may: disable this option
when lsof is built; change the name of the environment
variable from LSOFPERSDCPATH to something else; change the
HASPERSDC format to include the personal path component in
another place; or exclude the personal path component
entirely. Consult the output of the -D? option for the
environment variable's name and the HASPERSDC format spec-
ification.
DIAGNOSTICS
Errors are identified with messages on the standard error
file.
Lsof returns a one (1) if any error was detected, includ-
ing the failure to locate command names, file names,
Internet addresses or files, login names, NFS files, PIDs,
PGRPs, or UIDs it was asked to list. If the -V option is
specified, lsof will indicate the search items it failed
to list.
It returns a zero (0) if no errors were detected and if it
was able to list some information about all the specified
Revision-4.49 41
LSOF(8)LSOF(8)
search arguments.
When lsof cannot open access to /dev (or /devices) or one
of its subdirectories, or get information on a file in
them with stat(2), it issues a warning message and contin-
ues. That lsof will issue warning messages about inacces-
sible files in /dev (or /devices) is indicated in its help
output - requested with the -h or >B -? options - with
the message:
Inaccessible /dev warnings are enabled.
The warning message may be suppressed with the -w option.
It may also have been suppressed by the system administra-
tor when lsof was compiled by the setting of the WARNDE-
VACCESS definition. In this case, the output from the
help options will include the message:
Inaccessible /dev warnings are disabled.
Inaccessible device warning messages usually disappear
after lsof has created a working device cache file.
EXAMPLES
For a more extensive set of examples, documented more
fully, see the 00QUICKSTART file of the lsof distribution.
To list all open files, use:
lsof
To list all open Internet, x.25 (HP-UX), and UNIX domain
files, use:
lsof-i -U
To list all files using any protocol on ports 513, 514, or
515 of host wonderland.cc.purdue.edu, use:
lsof-i @wonderland.cc.purdue.edu:513-515
To list all files using any protocol on any port of
mace.cc.purdue.edu (cc.purdue.edu is the default domain),
use:
lsof-i @mace
To list all open files for login name ``abe'', or user ID
1234, or process 456, or process 123, or process 789, use:
lsof-p 456,123,789 -u 1234,abe
To list all open files on device /dev/hd4, use:
Revision-4.49 42
LSOF(8)LSOF(8)lsof /dev/hd4
To find the process that has /u/abe/foo open, use:
lsof /u/abe/foo
To send a SIGHUP to the processes that have /u/abe/bar
open, use:
kill -HUP `lsof -t /u/abe/bar`
To find any open file, including an open UNIX domain
socket file, with the name /dev/log, use:
lsof /dev/log
To find processes with open files on the NFS file system
named /nfs/mount/point whose server is inaccessible, and
presuming your mount table supplies the device number for
/nfs/mount/point, use:
lsof-b /nfs/mount/point
To do the preceding search with warning messages sup-
pressed, use:
lsof-bw /nfs/mount/point
To ignore the device cache file, use:
lsof-Di
To obtain PID and command name field output for each pro-
cess, file descriptor, file device number, and file inode
number for each file of each process, use:
lsof-FpcfDi
To list the files at descriptors 1 and 3 of every process
running the lsof command for login ID ``abe'' every 10
seconds, use:
lsof-clsof-a -d 1 -d 3 -u abe -r10
To find an IP version 4 socket file by its associated
numeric dot-form address, use:
lsof -i@128.210.15.17
To find an IP version 6 socket file (when the UNIX dialect
supports IPv6) by its associated numeric colon-form
address, use:
lsof -i@[0:1:2:3:4:5:6:7]
Revision-4.49 43
LSOF(8)LSOF(8)
To find an IP version 6 socket file (when the UNIX dialect
supports IPv6) by an associated numeric colon-form address
that has a run of zeroes in it - e.g., the loop-back
address - use:
lsof -i@[::1]
BUGS
Since lsof reads kernel memory in its search for open
files, rapid changes in kernel memory may produce unpre-
dictable results.
When a file has multiple record locks, the lock status
character (following the file descriptor) is derived from
a test of the first lock structure, not from any combina-
tion of the individual record locks that might be
described by multiple lock structures.
Lsof can't search for files with restrictive access per-
missions by name unless it is installed with root set-UID
permission. Otherwise it is limited to searching for
files to which its user or its set-GID group (if any) has
access permission.
The display of the destination address of a raw socket
(e.g., for ping) depends on the UNIX operating system.
Some dialects store the destination address in the raw
socket's protocol control block, some do not.
Lsof can't always represent Solaris and SunOS device num-
bers in the same way that ls(1) does. For example, the
major and minor device numbers that the lstat(2) and
stat(2) functions report for the directory on which CD-ROM
files are mounted (typically /cdrom) are not the same as
the ones that it reports for the device on which CD-ROM
files are mounted (typically /dev/sr0). (Lsof reports the
directory numbers.)
The support for /proc file systems is available only for
BSD, DEC OSF/1, Digital UNIX, and Tru64 UNIX dialects,
Linux, and dialects derived from SYSV R4 - e.g., FreeBSD,
NetBSD, OpenBSD, Solaris, UnixWare.
Some /proc file items - device number, inode number, and
file size - are unavailable in some dialects. Searching
for files in a /proc file system may require that the full
path name be specified.
No text (txt) file descriptors are displayed for Linux
processes. All entries for files other than the current
working directory, the root directory, and numerical file
descriptors are labeled mem descriptors.
Door file system support under Solaris 2.5 and above is
Revision-4.49 44
LSOF(8)LSOF(8)
minimal, since the file system type is new and experimen-
tal. Sun advises that the door file system and its inter-
face are subject to change in future releases.
Lsof can't search for DEC OSF/1, Digital UNIX, and Tru64
UNIX named pipes by name, because their kernel implementa-
tion of lstat(2) returns an improper device number for a
named pipe.
Lsof can't report fully or correctly on HP-UX 9.01, 10.20,
and 11.00 locks because of insufficient access to kernel
data or errors in the kernel data. See the 00FAQ file of
the lsof distribution for details.
The AIX SMT file type is a fabrication. It's made up for
file structures whose type (15) isn't defined in the AIX
/usr/include/sys/file.h header file. One way to create
such file structures is to run X clients with the DISPLAY
variable set to ``:0.0''.
The +|-f[cfgGn] option is not supported under /proc-based
Linux lsof, because it doesn't read kernel structures from
kernel memory.
ENVIRONMENT
Lsof may access these environment variables.
LSOFDEVCACHE defines the path to a device cache file.
See the DEVICE CACHE PATH FROM AN ENVI-
RONMENT VARIABLE section for more infor-
mation.
LSOFPERSDCPATH defines the middle component of a modi-
fied personal device cache file path.
See the MODIFIED PERSONAL DEVICE CACHE
PATH section for more information.
FILES
/dev/kmem kernel virtual memory device
/dev/mem physical memory device
/dev/swap system paging device
.lsof_hostname lsof's device cache file (The suffix,
hostname, is the first component of the
host's name returned by gethostname(2).)
AUTHORS
Lsof was written by Victor A. Abell <abe@purdue.edu> of
the Purdue University Computing Center (PUCC). Many oth-
ers have contributed to lsof. They're listed in the
00CREDITS file of the lsof distribution.
Revision-4.49 45
LSOF(8)LSOF(8)DISTRIBUTION
The latest distribution of lsof is available via anonymous
ftp from the host vic.cc.purdue.edu. You'll find the lsof
distribution in the pub/tools/unix/lsof directory.
Lsof is also mirrored elsewhere. When you access
vic.cc.purdue.edu and change to its pub/tools/unix/lsof
directory, you'll be given a list of some mirror sites.
The pub/tools/unix/lsof directory also contains a more
complete list in its mirrors file. Use mirrors with cau-
tion - not all mirrors always have the latest lsof revi-
sion.
Some pre-compiled Lsof executables are available on
vic.cc.purdue.edu, but their use is discouraged - it's
better that you build your own from the sources. If you
feel you must use a pre-compiled executable, please read
the cautions that appear in the README files of the
pub/tools/unix/lsof/binaries subdirectories and in the 00*
files of the distribution.
More information on the lsof distribution can be found in
its README.lsof_<version> file. If you intend to get the
lsof distribution and build it, please read
README.lsof_<version> and the other 00* files of the dis-
tribution before sending questions to the author.
SEE ALSO
Lsof versions 2 and 3 have been tested under older UNIX
dialects. They are available via anonymous ftp from
vic.cc.purdue.edu in the pub/tools/unix/lsof/OLD direc-
tory.
access(2), awk(1), crash(1), fattach(3C), ff(1), fstat(8),
fuser(1), gethostname(2), kill(1), lstat(2), modload(8),
mount(8), netstat(1), ofiles(8L), perl(1), ps(1), read-
link(2), stat(2), uname(1).
Revision-4.49 46
