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LSOF(8) System Manager's Manual LSOF(8)
lsof - list open files
lsof [ -?abChlnNOPRtUvVX ] [ -A A ] [ -c c ] [ +c c ] [ +|-d d ]
[ +|-D D ] [ +|-e s ] [ +|-E ] [ +|-f [cfgGn] ] [ -F [f] ] [ -g
[s] ] [ -i [i] ] [ -k k ] [ -K k ] [ +|-L [l] ] [ +|-m m ] [ +|-M
] [ -o [o] ] [ -p s ] [ +|-r [t[m<fmt>]] ] [ -s [p:s] ] [ -S [t]
] [ -T [t] ] [ -u s ] [ +|-w ] [ -x [fl] ] [ -z [z] ] [ -Z [Z] ]
[ -- ] [names]
Lsof revision 4.91 lists on its standard output file information
about files opened by processes for the following UNIX dialects:
Apple Darwin 9 and Mac OS X 10.[567]
FreeBSD 8.[234], 9.0 and 1[012].0 for AMD64-based systems
Linux 2.1.72 and above for x86-based systems
Solaris 9, 10 and 11
(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 output, delay, then
repeat the output operation until stopped with an interrupt or
quit signal. See the +|-r [t[m<fmt>]] option description for
more information.
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''. The exceptions are:
1) the `^' (negated) login name or user ID (UID), specified with
the -u option;
2) the `^' (negated) process ID (PID), specified with the -p
option;
3) the `^' (negated) process group ID (PGID), specified with the
-g option;
4) the `^' (negated) command, specified with the -c option;
5) the (`^') negated TCP or UDP protocol state names, specified
with the -s [p:s] option.
Since they represent exclusions, they are applied without ORing
or ANDing and take 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, zone names, security contexts - are joined in a
single ORed set and applied before the result participates in
ANDing. Thus, for example, 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, -S, -T, -x and -z. 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 identifier character following the -F
option. When ambiguity is possible, start a new option with a
`-' character - e.g., ``-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 displayed messages explaining each error. (Escape
the `?' character as your shell requires.)
-a causes list selection options to be ANDed, as described
above.
-A A 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 lsof FAQ (The FAQ section gives its
location.) for more information about dynamic modules,
their symbols, and how they affect lsof.
-b 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 selects the listing of files for processes executing 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 with a `^', then the following characters
specify a command name whose processes are to be ignored
(excluded.)
If c begins and ends with a slash ('/'), the characters
between the slashes are 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 (The FAQ section gives its location.)
for more information on basic and extended regular
expressions.
The simple command specification is tested first. If that
test fails, the command regular expression is applied. If
the simple command test succeeds, the command regular
expression test isn't made. This may result in ``no
command found for regex:'' messages when lsof's -V option
is specified.
+c w defines the maximum number of initial characters of the
name, supplied by the UNIX dialect, of the UNIX command
associated with a process to be printed in the COMMAND
column. (The lsof default is nine.)
Note that many UNIX dialects do not supply all command
name characters to lsof in the files and structures from
which lsof obtains command name. Often dialects limit the
number of characters supplied in those sources. For
example, Linux 2.4.27 and Solaris 9 both limit command
name length to 16 characters.
If w is zero ('0'), all command characters supplied to
lsof by the UNIX dialect will be printed.
If w is less than the length of the column title,
``COMMAND'', it will be raised to that length.
-C disables the reporting of any path name components from
the kernel's name cache. See the KERNEL NAME CACHE
section for more information.
+d s causes lsof to search for all open instances of directory
s and the files and directories it contains at its top
level. +d does NOT descend the directory tree, rooted at
s. The +D D option may be used to request a full-descent
directory tree search, rooted at directory D.
Processing of the +d option does not follow symbolic links
within s unless the -x or -x l option is also specified.
Nor does it search for open files on file system mount
points on subdirectories of s unless the -x or -x f
option is also specified.
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 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 descriptors 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 causes lsof to search for all open instances of directory
D and all the files and directories it contains to its
complete depth.
Processing of the +D option does not follow symbolic links
within D unless the -x or -x l option is also specified.
Nor does it search for open files on file system mount
points on subdirectories of D unless the -x or -x f
option is also specified.
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 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 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 prevents it from
creating a new device cache file when none exists or the
existing one is improperly 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 specified.
+|-e s exempts the file system whose path name is s from being
subjected to kernel function calls that might block. The
+e option exempts stat(2), lstat(2) and most readlink(2)
kernel function calls. The -e option exempts only stat(2)
and lstat(2) kernel function calls. Multiple file systems
may be specified with separate +|-e specifications and
each may have readlink(2) calls exempted or not.
This option is currently implemented only for Linux.
CAUTION: this option can easily be mis-applied to other
than the file system of interest, because it uses path
name rather than the more reliable device and inode
numbers. (Device and inode numbers are acquired via the
potentially blocking stat(2) kernel call and are thus not
available, but see the +|-m m option as a possible
alternative way to supply device numbers.) Use this
option with great care and fully specify the path name of
the file system to be exempted.
When open files on exempted file systems are reported, it
may not be possible to obtain all their information.
Therefore, some information columns will be blank, the
characters ``UNKN'' preface the values in the TYPE column,
and the applicable exemption option is added in
parentheses to the end of the NAME column. (Some device
number information might be made available via the +|-m m
option.)
+|-E +E specifies that Linux pipe, Linux UNIX socket and Linux
pseudoterminal files should be displayed with endpoint
information and the files of the endpoints should also be
displayed. Note: UNIX socket file endpoint information is
only available when the compile flags line of -v output
contains HASUXSOCKEPT, and psudoterminal endpoint
information is only available when the compile flags line
contains HASPTYEPT.
Pipe endpoint information is displayed in the NAME column
in the form ``PID,cmd,FDmode'', where PID is the endpoint
process ID; cmd is the endpoint process command; FD is the
endpoint file's descriptor; and mode is the endpoint
file's access mode.
Pseudoterminal endpoint information is displayed in the
NAME column as ``->/dev/ptsmin PID,cmd,FDmode'' or
``PID,cmd,FDmode''. The first form is for a master
device; the second, for a slave device. min is a slave
device's minor device number; and PID, cmd, FD and mode
are the same as with pipe endpoint information. Note:
psudoterminal endpoint information is only available when
the compile flags line of -V output contains HASPTYEPT.
UNIX socket file endpoint information is displayed in the
NAME column in the form
``type=TYPE ->INO=INODE PID,cmd,FDmode'', where TYPE is
the socket type; INODE is the i-node number of the
connected socket; and PID, cmd, FD and mode are the same
as with pipe endpoint information. Note: UNIX socket file
endpoint information is available only when the compile
flags line of -v output contains HASUXSOCKEPT.
Multiple occurrences of this information can appear in a
file's NAME column.
-E specfies that Linux pipe and Linux UNIX socket files
should be displayed with endpoint information, but not the
files of the endpoints.
+|-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 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 by itself, 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 and -f are properly terminated
and aren'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 and -f as in these examples.
$ lsof +f -- /file/system/name
$ lsof -f -- /file/name
The listing of information from kernel file structures,
requested with the +f [cfgGn] option form, is normally
inhibited, and is not available in whole or part for some
dialects - e.g., /proc-based Linux kernels below 2.6.22.
When the prefix to f is a plus sign (`+'), these
characters request file structure information:
c file structure use count (not Linux)
f file structure address (not Linux)
g file flag abbreviations (Linux 2.6.22 and up)
G file flags in hexadecimal (Linux 2.6.22 and up)
n file structure node address (not Linux)
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 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, or by a C
program.
-F f 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 process.
When the field selection character list is empty, all
standard fields are selected (except the raw device field,
security context and zone 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
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 help list of the
field identification characters. (Escape the `?'
character as your shell requires.)
-g [s] excludes or 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.)
PGID numbers that begin with `^' (negation) represent
exclusions.
Multiple PGID numbers are joined in a single ORed set
before participating in AND option selection. However,
PGID exclusions are applied without ORing or ANDing and
take effect before other selection criteria are applied.
The -g option also enables the output display of PGID
numbers. When specified without a PGID set that's all it
does.
-i [i] 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
displayed. (An IPv6 specification may be used only if the
dialects supports IPv6, as indicated by ``[46]'' and
``IPv[46]'' in lsof's -h or -? output.) Sequentially
specifying -i4, followed by -i6 is the same as specifying
-i, and vice-versa. Specifying -i4, or -i6 after -i is
the same as specifying -i4 or -i6 by itself.
Multiple addresses (up to a limit of 100) may be specified
with multiple -i options. (A port number 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 (Items in
square brackets are optional.):
[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, 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.
IPv6 options may be used only if the UNIX dialect supports
IPv6. To see if the dialect supports IPv6, run lsof and
specify the -h or -? (help) option. If the displayed
description of the -i option contains ``[46]'' and
``IPv[46]'', IPv6 is supported.
IPv4 host names and addresses may not be specified if
network file selection is limited to IPv6 with -i 6. IPv6
host names and addresses may not be specified if network
file selection is limited to IPv4 with -i 4. When an open
IPv4 network file's address is mapped in an IPv6 address,
the open file's type will be IPv6, not IPv4, and its
display will be selected by '6', not '4'.
At least one address component - 4, 6, protocol, hostname,
hostaddr, or service - must be supplied. The `@'
character, leading the host specification, is always
required; as is the `:', leading the port specification.
Specify either hostname or hostaddr. Specify either
service name list or port number list. If a service name
list is specified, the protocol may also need to be
specified if the TCP, UDP and UDPLITE port numbers 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 specified protocol. Since service names may contain
embedded minus signs, the starting entry of a range can't
be a service name; it can be a port number, however.
Here are 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:1ebc::1]:1234 - Internet IPv6 host address
3ffe:1ebc::1, port 1234
UDP:who - UDP who service port
[email protected]: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:1-smtp - TCP, ports 1 through smtp, host bar
:time - either TCP, UDP or UDPLITE time service port
-K k selects the listing of tasks (threads) of processes, on
dialects where task (thread) reporting is supported. (If
help output - i.e., the output of the -h or -? options -
shows this option, then task (thread) reporting is
supported by the dialect.)
If -K is followed by a value, k, it must be ``i''. That
causes lsof to ignore tasks, particularly in the default,
list-everything case when no other options are specified.
When -K and -a are both specified on Linux, and the tasks
of a main process are selected by other options, the main
process will also be listed as though it were a task, but
without a task ID. (See the description of the TID column
in the OUTPUT section.)
Where the FreeBSD version supports threads, all threads
will be listed with their IDs.
In general threads and tasks inherit the files of the
caller, but may close some and open others, so lsof always
reports all the open files of threads and tasks.
-k k specifies a kernel name list file, k, in place of /vmunix,
/mach, etc. -k is not available under AIX on the IBM
RISC/System 6000.
-l 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]
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 <file_system>'' 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 specifies an alternate kernel memory file or activates
mount table supplement processing.
The option form -m m specifies a kernel memory file, m, in
place of /dev/kmem or /dev/mem - e.g., a crash dump file.
The option form +m requests that a mount supplement file
be written to the standard output file. All other options
are silently ignored.
There will be a line in the mount supplement file for each
mounted file system, containing the mounted file system
directory, followed by a single space, followed by the
device number in hexadecimal "0x" format - e.g.,
/ 0x801
Lsof can use the mount supplement file to get device
numbers for file systems when it can't get them via
stat(2) or lstat(2).
The option form +m m identifies m as a mount supplement
file.
Note: the +m and +m m options are not available for all
supported dialects. Check the output of lsof's -h or -?
options to see if the +m and +m m options are available.
+|-M Enables (+) or disables (-) the reporting of portmapper
registrations for local TCP, UDP and UDPLITE ports, where
port mapping is supported. (See the last paragraph of
this option description for information about where
portmapper registration reporting is supported.)
The default reporting mode is set by the lsof builder with
the HASPMAPENABLED #define in the dialect's machine.h
header file; lsof is distributed with the HASPMAPENABLED
#define deactivated, so portmapper reporting is disabled
by default and must be requested with +M. Specifying
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. When portmapper registration reporting is
enabled, lsof displays the portmapper registration (if
any) for local TCP, UDP or UDPLITE ports in square
brackets immediately following the port numbers or service
names - e.g., ``:1234[name]'' or ``:name[100083]''. The
registration information may be a name or number,
depending on what the registering program supplied to the
portmapper 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
registration reporting is slowing or blocking lsof.
For purposes of portmapper registration reporting lsof
considers a TCP, UDP or UDPLITE 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 foreign Internet address
is on a different interface from the local one.
See the lsof FAQ (The FAQ section gives its location.)
for further discussion of portmapper registration
reporting issues.
Portmapper registration reporting is supported only on
dialects that have RPC header files. (Some Linux
distributions with GlibC 2.14 do not have them.) When
portmapper registration reporting is supported, the -h or
-? help output will show the +|-M option.
-n 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 selects the listing of NFS files.
-o directs lsof to display file offset at all times. It
causes the SIZE/OFF output column title to be changed to
OFFSET. Note: on some UNIX dialects lsof can't obtain
accurate or consistent file offset information from its
kernel data sources, sometimes just for particular kinds
of files (e.g., socket files.) Consult the lsof FAQ (The
FAQ section gives its location.) for more information.
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 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 offset at all
times; specify -o (without a trailing number) to do that.
-o o 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 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 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 excludes or selects the listing of files for the processes
whose optional process IDentification (PID) numbers are in
the comma-separated set s - e.g., ``123'' or ``123,^456''.
(There should be no spaces in the set.)
PID numbers that begin with `^' (negation) represent
exclusions.
Multiple process ID numbers are joined in a single ORed
set before participating in AND option selection.
However, PID exclusions are applied without ORing or
ANDing and take effect before other selection criteria are
applied.
-P 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 port name
lookup is not working properly.
+|-r [t[m<fmt>]]
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
prefix 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 default
marker is `m'; otherwise the default marker is
``========''. The marker is followed by a NL character.
The optional "m<fmt>" argument specifies a format for the
marker line. The <fmt> characters following `m' are
interpreted as a format specification to the strftime(3)
function, when both it and the localtime(3) function are
available in the dialect's C library. Consult the
strftime(3) documentation for what may appear in its
format specification. Note that when field output is
requested with the -F option, <fmt> cannot contain the NL
format, ``%n''. Note also that when <fmt> contains spaces
or other characters that affect the shell's interpretation
of arguments, <fmt> must be quoted appropriately.
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 example.
To use repeat mode most efficiently, accompany +|-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, or a C program.
-R directs lsof to list the Parent Process IDentification
number in the PPID column.
-s [p:s]
s alone 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 optional -s p:s form is available only for selected
dialects, and only when the -h or -? help output lists
it.
When the optional form is available, the s may be followed
by a protocol name (p), either TCP or UDP, a colon (`:')
and a comma-separated protocol state name list, the option
causes open TCP and UDP files to be excluded if their
state name(s) are in the list (s) preceded by a `^'; or
included if their name(s) are not preceded by a `^'.
Dialects that support this option may support only one
protocol. When an unsupported protocol is specified, a
message will be displayed indicating state names for the
protocol are unavailable.
When an inclusion list is defined, only network files with
state names in the list will be present in the lsof
output. Thus, specifying one state name means that only
network files with that lone state name will be listed.
Case is unimportant in the protocol or state names, but
there may be no spaces and the colon (`:') separating the
protocol name (p) and the state name list (s) is required.
If only TCP and UDP files are to be listed, as controlled
by the specified exclusions and inclusions, the -i option
must be specified, too. If only a single protocol's files
are to be listed, add its name as an argument to the -i
option.
For example, to list only network files with TCP state
LISTEN, use:
-iTCP -sTCP:LISTEN
Or, for example, to list network files with all UDP states
except Idle, use:
-iUDP -sUDP:Idle
State names vary with UNIX dialects, so it's not possible
to provide a complete list. Some common TCP state names
are: CLOSED, IDLE, BOUND, LISTEN, ESTABLISHED, SYN_SENT,
SYN_RCDV, ESTABLISHED, CLOSE_WAIT, FIN_WAIT1, CLOSING,
LAST_ACK, FIN_WAIT_2, and TIME_WAIT. Two common UDP state
names are Unbound and Idle.
See the lsof FAQ (The FAQ section gives its location.)
for more information on how to use protocol state
exclusion and inclusion, including examples.
The -o (without a following decimal digit count) and -s
option (without a following protocol and state name list)
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.
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] 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, fifteen; when no value is specified, the default
is used.
See the BLOCKS AND TIMEOUTS section for more information.
-T [t] controls the reporting of some TCP/TPI information, also
reported by netstat(1), following the network addresses.
In normal output the information appears in parentheses,
each item except TCP or TPI state name identified by a
keyword, followed by `=', separated from others by a
single space:
<TCP or TPI state name>
QR=<read queue length>
QS=<send queue length>
SO=<socket options and values>
SS=<socket states>
TF=<TCP flags and values>
WR=<window read length>
WW=<window write length>
Not all values are reported for all UNIX dialects. Items
values (when available) are reported after the item name
and '='.
When the field output mode is in effect (See OUTPUT FOR
OTHER PROGRAMS.) each item appears as a field with a `T'
leading character.
-T with no following key characters disables TCP/TPI
information reporting.
-T with following characters selects the reporting of
specific TCP/TPI information:
f selects reporting of socket options,
states and values, and TCP flags and
values.
q selects queue length reporting.
s selects connection state reporting.
w selects window size reporting.
Not all selections are enabled for some UNIX dialects.
State may be selected for all dialects and is reported by
default. The -h or -? help output for the -T option will
show what selections may be used with the UNIX dialect.
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.
Socket options, socket states, some socket values, TCP
flags and one TCP value may be reported (when available in
the UNIX dialect) in the form of the names that commonly
appear after SO_, so_, SS_, TCP_ and TF_ in the dialect's
header files - most often <sys/socket.h>,
<sys/socketvar.h> and <netinet/tcp_var.h>. Consult those
header files for the meaning of the flags, options, states
and values.
``SO='' precedes socket options and values; ``SS='',
socket states; and ``TF='', TCP flags and values.
If a flag or option has a value, the value will follow an
'=' and the name -- e.g., ``SO=LINGER=5'', ``SO=QLIM=5'',
``TF=MSS=512''. The following seven values may be
reported:
Name
Reported Description (Common Symbol)
KEEPALIVE keep alive time (SO_KEEPALIVE)
LINGER linger time (SO_LINGER)
MSS maximum segment size (TCP_MAXSEG)
PQLEN partial listen queue connections
QLEN established listen queue connections
QLIM established listen queue limit
RCVBUF receive buffer length (SO_RCVBUF)
SNDBUF send buffer length (SO_SNDBUF)
Details on what socket options and values, socket states,
and TCP flags and values may be displayed for particular
UNIX dialects may be found in the answer to the ``Why
doesn't lsof report socket options, socket states, and TCP
flags and values for my dialect?'' and ``Why doesn't lsof
report the partial listen queue connection count for my
dialect?'' questions in the lsof FAQ (The FAQ section
gives its location.)
-t 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). -t selects the -w option.
-u s 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 selection is neither ANDed nor ORed
with other selections; 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 selects the listing of UNIX domain socket files.
-v selects the listing of lsof version information,
including: revision number; when the 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 compiler and loader flags used to construct the lsof
binary; and system information, typically the output of
uname's -a option.
-V 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
compile-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.
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. A similar situation arises when
HASSECURITY and HASNOSOCKSECURITY are defined at compile
time and they prevent the listing of open files.
+|-w Enables (+) or disables (-) the suppression of warning
messages.
The lsof builder may choose to have warning messages
disabled or enabled by default. The default warning
message state is indicated in the output of the -h or -?
option. Disabling warning messages when they are already
disabled or enabling them when already enabled is
acceptable.
The -t option selects the -w option.
-x [fl]
may accompany the +d and +D options to direct their
processing to cross over symbolic links and|or file system
mount points encountered when scanning the directory (+d)
or directory tree (+D).
If -x is specified by itself without a following
parameter, cross-over processing of both symbolic links
and file system mount points is enabled. Note that when
-x is specified without a parameter, the next argument
must begin with '-' or '+'.
The optional 'f' parameter enables file system mount point
cross-over processing; 'l', symbolic link cross-over
processing.
The -x option may not be supplied without also supplying a
+d or +D option.
-X This is a dialect-specific option.
AIX:
This IBM AIX RISC/System 6000 option requests the
reporting of executed text file and shared library
references.
WARNING: because this option uses the kernel readx()
function, its use 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 its happening, but I think
there is a remote possibility it could happen.
By default use of readx() is disabled. On AIX 5L and
above lsof may need setuid-root permission to perform
the actions this option requests.
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 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 kernel error, known as the Stale
Segment ID bug.
The readx() function, used by lsof or any other program
to access some sections of kernel virtual memory, can
trigger the Stale Segment ID bug. It can cause the
kernel's dir_search() function to believe erroneously
that part of an in-memory copy of a file system
directory has been zeroed. Another application process,
distinct 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 lsof FAQ (The FAQ section gives its
location.) and the 00README file 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.
Linux:
This Linux option requests that lsof skip the reporting
of information on all open TCP, UDP and UDPLITE IPv4 and
IPv6 files.
This Linux option is most useful when the system has an
extremely large number of open TCP, UDP and UDPLITE
files, the processing of whose information in the
/proc/net/tcp* and /proc/net/udp* files would take lsof
a long time, and whose reporting is not of interest.
Use this option with care and only when you are sure
that the information you want lsof to display isn't
associated with open TCP, UDP or UDPLITE socket files.
Solaris 10 and above:
This Solaris 10 and above option requests the reporting
of cached paths for files that have been deleted - i.e.,
removed with rm(1) or unlink(2).
The cached path is followed by the string `` (deleted)''
to indicate that the path by which the file was opened
has been deleted.
Because intervening changes made to the path - i.e.,
renames with mv(1) or rename(2) - are not recorded in
the cached path, what lsof reports is only the path by
which the file was opened, not its possibly different
final path.
-z [z] specifies how Solaris 10 and higher zone information is
to be handled.
Without a following argument - e.g., NO z - the option
specifies that zone names are to be listed in the ZONE
output column.
The -z option may be followed by a zone name, z. That
causes lsof to list only open files for processes in
that zone. Multiple -z z option and argument pairs may
be specified to form a list of named zones. Any open
file of any process in any of the zones will be listed,
subject to other conditions specified by other options
and arguments.
-Z [Z] specifies how SELinux security contexts are to be
handled. It and 'Z' field output character support are
inhibited when SELinux is disabled in the running Linux
kernel. See OUTPUT FOR OTHER PROGRAMS for more
information on the 'Z' field output character.
Without a following argument - e.g., NO Z - the option
specifies that security contexts are to be listed in the
SECURITY-CONTEXT output column.
The -Z option may be followed by a wildcard security
context name, Z. That causes lsof to list only open
files for processes in that security context. Multiple
-Z Z option and argument pairs may be specified to form
a list of security contexts. Any open file of any
process in any of the security contexts will be listed,
subject to other conditions specified by other options
and arguments. Note that Z can be A:B:C or *:B:C or
A:B:* or *:*:C to match against the A:B:C context.
-- 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 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
associated 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 directory, such as the
root or current working directory. 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 multiplexed
files - e.g, AIX's /dev/pt[cs] - lsof will list all the
associated multiplexed 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
usually search for it by the characters of the name
alone - exactly as it is specified and is recorded in
the kernel socket structure. (See the next paragraph
for an exception to that rule for Linux.) 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 UNIX domain socket structures.
If a name is a Linux UNIX domain socket name, in one
case lsof is able to search for it by its device and
inode number, allowing name to be a relative path. The
case requires that the absolute path -- i.e., one
beginning with a slash ('/') be used by the process that
created the socket, and hence be stored in the
/proc/net/unix file; and it requires that lsof be able
to obtain the device and node numbers of both the
absolute path in /proc/net/unix and name via successful
stat(2) system calls. When those conditions are met,
lsof will be able to search for the UNIX domain socket
when some path to it is is specified in name. Thus, for
example, if the path is /dev/log, and an lsof search is
initiated when the working directory is /dev, then name
could be ./log.
If a name is none of the above, lsof will list 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 systems for which your
mount table supplies alternate 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.
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)
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 implemented 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 implementations 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 lsof FAQ (The FAQ section gives its location.) 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.
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 and HASNOSOCKSECURITY options. 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).
However, if HASSECURITY and HASNOSOCKSECURITY are both defined,
anyone may list open socket files, provided they are selected
with the -i option.
When HASSECURITY is not defined, anyone may list all open files.
Help output, presented in response to the -h or -? option, gives
the status of the HASSECURITY and HASNOSOCKSECURITY definitions.
See the Security section of the 00README file of the lsof
distribution for information on building lsof with the
HASSECURITY and HASNOSOCKSECURITY options enabled.
Creation and use of a user-readable and user-writable device
cache file is controlled by the compile-time HASDCACHE 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 file of the lsof
distribution and the lsof FAQ (The FAQ section gives its
location.)
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 memory
files with the -k and -m options, lsof checks the 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.
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 (declared so by isprint(3)) 8 bit
characters. Non-printable 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.
For some dialects - if HASSETLOCALE is defined in the dialect's
machine.h header file - lsof will print the extended 8 bit
characters of a language locale. The lsof process must be
supplied a language locale environment variable (e.g., LANG)
whose value represents a known language locale in which the
extended characters are considered printable by isprint(3).
Otherwise lsof considers the extended characters non-printable
and prints them according to its rules for non-printable
characters, stated above. Consult your dialect's setlocale(3)
man page for the names of other environment variables that may be
used in place of LANG - e.g., LC_ALL, LC_CTYPE, etc.
Lsof's language locale support for a dialect also covers wide
characters - e.g., UTF-8 - when HASSETLOCALE and HASWIDECHAR are
defined in the dialect's machine.h header file, and when a
suitable language locale has been defined in the appropriate
environment variable for the lsof process. Wide characters are
printable under those conditions if iswprint(3) reports them to
be. If HASSETLOCALE, HASWIDECHAR and a suitable language locale
aren't defined, or if iswprint(3) reports wide characters that
aren't printable, lsof considers the wide characters
non-printable and prints each of their 8 bits according to its
rules for non-printable characters, stated above.
Consult the answers to the "Language locale support" questions in
the lsof FAQ (The FAQ section gives its location.) for more
information.
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 process. If a non-zero w
value is specified to the +c w option, the column contains
the first w characters of the name of the UNIX command
associated with the process up to the limit of characters
supplied to lsof by the UNIX dialect. (See the
description of the +c w command or the lsof FAQ for more
information. The FAQ section gives its location.)
If w is less than the length of the column title,
``COMMAND'', it will be raised to that length.
If a zero w value is specified to the +c w option, the
column contains all the characters of the name of the UNIX
command associated with the process.
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 COMMANDS section for information on
selecting field output and the associated command name
descriptor.
PID is the Process IDentification number of the process.
TID is the task (thread) IDentification number, if task
(thread) reporting is supported by the dialect and a task
(thread) is being listed. (If help output - i.e., the
output of the -h or -? options - shows this option, then
task (thread) reporting is supported by the dialect.)
A blank TID column in Linux indicates a process - i.e., a
non-task.
TASKCMD
is the task command name. Generally this will be the same
as the process named in the COMMAND column, but some task
implementations (e.g., Linux) permit a task to change its
command name.
The TASKCMD column width is subject to the same size
limitation as the COMMAND column.
ZONE is the Solaris 10 and higher zone name. This column must
be selected with the -z option.
SECURITY-CONTEXT
is the SELinux security context. This column must be
selected with the -Z option. Note that the -Z option is
inhibited when SELinux is disabled in the running Linux
kernel.
PPID is the Parent Process IDentification number of the
process. It is only displayed when the -R option has been
specified.
PGID is the process group IDentification number associated with
the process. It is only displayed when the -g option has
been specified.
USER is the user ID number or login name of the user to whom
the process belongs, usually the same as reported by
ps(1). However, on Linux USER is the user ID number or
login that owns the directory in /proc where lsof finds
information about the process. Usually that is the same
value reported by ps(1), but may differ when the process
has changed its effective user ID. (See the -l option
description for information on when a user ID number or
login name is displayed.)
FD is the File Descriptor number of the file or:
cwd current working directory;
Lnn library references (AIX);
err FD information error (see NAME column);
jld jail directory (FreeBSD);
ltx shared library text (code and data);
Mxx hex memory-mapped type number xx.
m86 DOS Merge mapped file;
mem memory-mapped file;
mmap memory-mapped device;
pd parent directory;
rtd root directory;
tr kernel trace file (OpenBSD);
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 mode unknown and no lock
character follows;
`-' if mode unknown and lock
character follows.
The mode character is followed by one of these lock
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 contents constitutes a single field for
parsing in post-processing scripts.
TYPE is the type of the node associated with the file - e.g.,
GDIR, GREG, VDIR, VREG, etc.
or ``IPv4'' for an IPv4 socket;
or ``IPv6'' for an open IPv6 network file - even if its
address is IPv4, mapped in an IPv6 address;
or ``ax25'' for a Linux AX.25 socket;
or ``inet'' for an Internet domain socket;
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 ``DEL'' for a Linux map file that has been deleted;
or ``DIR'' for a directory;
or ``DOOR'' for a VDOOR file;
or ``FIFO'' for a FIFO special file;
or ``KQUEUE'' for a BSD style kernel event queue file;
or ``LINK'' for a symbolic link file;
or ``MPB'' for a multiplexed block file;
or ``MPC'' for a multiplexed character file;
or ``NOFD'' for a Linux /proc/<PID>/fd directory that
can't be opened -- the directory path appears in the NAME
column, followed by an error message;
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 directory;
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 directory;
or ``PFIL'' for an executable /proc file;
or ``PFPR'' for a /proc FP register set;
or ``PGD'' for a /proc/pagedata file;
or ``PGID'' 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 a 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;
or ``PSIN'' for a /proc/psinfo file;
or ``PSTA'' for a /proc status file;
or ``PSXSEM'' for a POSIX semaphore file;
or ``PSXSHM'' for a POSIX shared memory file;
or ``PTS'' for a /dev/pts 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;
or ``XNAM'' for an OpenServer Xenix special file of
unknown type;
or ``XSEM'' for an OpenServer Xenix semaphore file;
or ``XSD'' for an OpenServer Xenix shared data file;
or the four type number octets if the corresponding name
isn't known.
FILE-ADDR
contains the kernel file structure address when f has been
specified to +f;
FCT contains the file reference 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
available); `G' causes them to be displayed in
hexadecimal; `g', as short-hand names; two lists may be
displayed with entries separated by commas, 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
CIO concurrent I/O
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
DTY must be a directory
EVO event only
EX open for exec
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
NATM don't update atime
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
NFLK don't follow links
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
RC file and record locking cache
REV revoked
RSH shared read
RSYN read synchronization
RW read and write access
SL shared lock
SNAP cooked snapshot
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
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 contain
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))
LCK lock was applied
MP memory-mapped
OPIP open pending - in progress
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 commas, for a
character special, block special, regular, directory or
NFS file;
or ``memory'' for a memory file system node under 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 Tru64 UNIX
kernel 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 whatever value - size or offset - is
appropriate for the type of the file and the version of
lsof.
On some UNIX dialects lsof can't obtain accurate or
consistent file offset information from its kernel data
sources, sometimes just for particular kinds of files
(e.g., socket files.) In other cases, files don't have
true sizes - e.g., sockets, FIFOs, pipes - so lsof
displays for their sizes the content amounts it finds in
their kernel buffer descriptors (e.g., socket buffer size
counts or TCP/IP window sizes.) Consult the lsof FAQ (The
FAQ section gives its location.) for more information.
The file size is displayed in decimal; the offset 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 displays 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 displays 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 display appropriate
information about the current size or position of the file
if it is available in the kernel structures that define
the file.
NLINK contains the file link count when +L has been specified;
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;
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; the local host name or IP number is followed by a
colon (':'), the port, ``->'', and the two-part remote
address; IP addresses may be reported as numbers or names,
depending on the +|-M, -n, and -P options; colon-separated
IPv6 numbers are enclosed in square brackets; IPv4
INADDR_ANY and IPv6 IN6_IS_ADDR_UNSPECIFIED addresses, and
zero port numbers are represented by an asterisk ('*'); a
UDP destination address may be followed by the amount of
time elapsed since the last packet was sent to the
destination; TCP, UDP and UDPLITE remote addresses may be
followed by TCP/TPI information in parentheses - state
(e.g., ``(ESTABLISHED)'', ``(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
window size;
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 information, 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 a list of stream module names,
separated by ``->'';
or ``STR:'' followed by the SCO OpenServer stream device
and module names, separated by ``->'';
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), followed by the remote address
(if any);
or ``(dead)'' for disassociated Tru64 UNIX files -
typically terminal 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, 8, 9 or 10 UNIX
domain socket, created by the socketpair(3N) network
function;
or ``no PCB'' for 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) function);
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;
or ``dgram'' or ``stream'' for the type UnixWare 7.1.1 and
above in-kernel UNIX domain sockets, followed by a colon
(':') and the local path name when available, followed by
``->'' and the remote path name or kernel socket address
in hexadecimal when available;
or the association value, association index, endpoint
value, local address, local port, remote address and
remote port for Linux SCTP sockets;
or ``protocol: '' followed by the Linux socket's protocol
attribute.
For dialects that support a ``namefs'' file system, allowing one
file to be attached to another with fattach(3C), lsof will add
``(FA:<address1><direction><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 fattach'ed to
<address2>. <address1> may be omitted if it already appears in
the DEVICE column.
Lsof may add two parenthetical notes to the NAME column for open
Solaris 10 files: ``(?)'' if lsof considers the path name of
questionable accuracy; and ``(deleted)'' if the -X option has
been specified and lsof detects the open file's path name has
been deleted. Consult the lsof FAQ (The FAQ section gives its
location.) for more information on these NAME column additions.
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 information 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 processes
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 manual page or the lsof FAQ (The FAQ
section gives its location.) for more information.
When the -F option is specified, lsof produces output that is
suitable for processing by another program - e.g, an awk or Perl
script, or a C program.
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 identifier 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 command, the process group
IDentification (PGID) number, the task (thread) ID (TID), 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 identifier
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 - specification 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 supports the -F option; it selects
the output of all fields with NL terminators (the -F0 option pair
selects the output of all fields with NUL terminators). For
compatibility reasons neither -F nor -F0 select the raw device
field.
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 (always selected)
F file structure address (0x<hexadecimal>)
G file flaGs (0x<hexadecimal>; names if +fg follows)
g process group ID
i file's inode number
K tasK ID
k link count
l file's lock status
L process login name
m marker between repeated output
M the task comMand name
n file name, comment, Internet address
N node identifier (ox<hexadecimal>
o file's offset (decimal)
p process ID (always selected)
P protocol name
r raw device number (0x<hexadecimal>)
R parent process ID
s file's size (decimal)
S file's stream identification
t file's type
T TCP/TPI information, identified by prefixes (the
`=' is part of the prefix):
QR=<read queue size>
QS=<send queue size>
SO=<socket options and values> (not all dialects)
SS=<socket states> (not all dialects)
ST=<connection state>
TF=<TCP flags and values> (not all dialects)
WR=<window read size> (not all dialects)
WW=<window write size> (not all dialects)
(TCP/TPI information isn't reported for all supported
UNIX dialects. The -h or -? help output for the
-T option will show what TCP/TPI reporting can be
requested.)
u process user ID
z Solaris 10 and higher zone name
Z SELinux security context (inhibited when SELinux is disabled)
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.) Additional
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 mutually
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 exclusive 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).
Three 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 storing them in a table,
and explanation strings that may be 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 distribution.
The third aid is the C library used for the lsof test suite. The
test suite is written in C and uses field output to validate the
correct operation of lsof. The library can be found in the
tests/LTlib.c file of the lsof distribution. The library uses
the first aid, the lsof_fields.h header file.
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 suppressed 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.
You can use the -b option to tell lsof to avoid using kernel
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 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.
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 supported 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. Note: you must be able to edit the
file - i.e., some mount tables like recent Solaris /etc/mnttab or
Linux /proc/mounts are read-only and can't be modified.
You may also be able to supply device numbers using the +m and +m
m options, provided they are supported by your dialect. Check
the output of lsof's -h or -? options to see if the +m and +m m
options are available.
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.
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, Apple
Darwin, FreeBSD, NetBSD, OpenBSD, and Tru64 UNIX. 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 ...''.
Lsof is able to examine the kernel's name cache or use other
kernel facilities (e.g., the ADVFS 4.x tag_to_path() function
under 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; some Solaris VxFS file system operations apparently
don't use it, either.)
Lsof reports the complete paths it finds in the NAME column. 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 `/' character.
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 kernel 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., 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 lsof FAQ (The FAQ section gives its location.)
has more information on this situation.
Lsof can report path name components for these dialects:
FreeBSD
HP-UX
Linux
NetBSD
NEXTSTEP
OpenBSD
OPENSTEP
SCO OpenServer
SCO|Caldera UnixWare
Solaris
Tru64 UNIX
Lsof can't report path name components for these dialects:
AIX
If you want to know why lsof can't report path name components
for some dialects, see the lsof FAQ (The FAQ section gives its
location.)
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.
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 specified 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 ownership
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.
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.
HP-UX 11.11 and 11.23
Linux
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 ``system''.
An lsof process that has setgid permission usually 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 distribution recommends that versions for
these dialects run setgid and be allowed to surrender setgid
permission.
AIX 5.[12] and 5.3-ML1
Apple Darwin 7.x Power Macintosh systems
FreeBSD 4.x, 4.1x, 5.x and [6789].x for x86-based systems
FreeBSD 5.x, [6789].x and 1[012].8for Alpha, AMD64 and Sparc64
based systems
HP-UX 11.00
NetBSD 1.[456], 2.x and 3.x for Alpha, x86, and SPARC-based
systems
NEXTSTEP 3.[13] for NEXTSTEP architectures
OpenBSD 2.[89] and 3.[0-9] for x86-based systems
OPENSTEP 4.x
SCO OpenServer Release 5.0.6 for x86-based systems
SCO|Caldera UnixWare 7.1.4 for x86-based systems
Solaris 2.6, 8, 9 and 10
Tru64 UNIX 5.1
(Note: lsof for AIX 5L and above needs setuid-root permission if
its -X option is used.)
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
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 specific 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 implementations that normally
don't surrender their setgid permission.)
A further -D function, i (for ignore), is always 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 argument 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.
Lsof's second choice for the device cache file is the contents 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 section for information on
implementations that don't surrender 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 environment
variable's name.
The local system administrator may choose to have a system-wide
device cache file when building lsof. That file will generally
be constructed by a special system administration 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.
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).
The default device cache file path of the lsof distribution is
one recorded in the home directory of the real UID that executes
lsof. Added to the home directory is a second 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 system-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 gethostname(2) output if it
contains no `.'.
The device cache file belongs to the user ID and is readable 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 hostname 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 conversions
used in the format specification are described in the 00DCACHE
file of the lsof distribution.
If this option is defined by the local system administrator 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 path at
the place marked by the local system administrator with the
``%p'' conversion in the HASPERSDC format specification 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
``lsof.itap.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 LSOFPERSDCPATH 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 commands.
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 specification.
Errors are identified with messages on the standard error file.
Lsof returns a one (1) if any error was detected, including the
failure to locate command names, file names, Internet addresses
or files, login names, NFS files, PIDs, PGIDs, 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 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 continues. That lsof
will issue warning messages about inaccessible 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 administrator when lsof
was compiled by the setting of the WARNDEVACCESS 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.
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 open IPv4 network files in use by the process whose
PID is 1234, use:
lsof -i 4 -a -p 1234
Presuming the UNIX dialect supports IPv6, to list only open IPv6
network files, use:
lsof -i 6
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:
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 suppressed, 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 process,
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 -c lsof -a -d 1 -d 3 -u abe -r10
To list the current working directory of processes running a
command that is exactly four characters long and has an 'o' or
'O' in character three, use this regular expression form of the
-c c option:
lsof -c /^..o.$/i -a -d cwd
To find an IP version 4 socket file by its associated numeric
dot-form address, use:
lsof [email protected]
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]
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]
To obtain a repeat mode marker line that contains the current
time, use:
lsof -rm====%T====
To add spaces to the previous marker line, use:
lsof -r "m==== %T ===="
Since lsof reads kernel memory in its search for open files,
rapid changes in kernel memory may produce unpredictable 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 combination of the individual
record locks that might be described by multiple lock structures.
Lsof can't search for files with restrictive access permissions
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 device numbers 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 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.
Lsof can't search for Tru64 UNIX named pipes by name, because
their kernel implementation 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 lsof FAQ (The FAQ section
gives its location.) 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.
Lsof may access these environment variables.
LANG defines a language locale. See setlocale(3) for the names
of other variables that can be used in place of LANG -
e.g., LC_ALL, LC_TYPE, etc.
LSOFDEVCACHE
defines the path to a device cache file. See the DEVICE
CACHE PATH FROM AN ENVIRONMENT VARIABLE section for more
information.
LSOFPERSDCPATH
defines the middle component of a modified personal device
cache file path. See the MODIFIED PERSONAL DEVICE CACHE
PATH section for more information.
Frequently-asked questions and their answers (an FAQ) are
available in the 00FAQ file of the lsof distribution.
That file is also available via anonymous ftp from
lsof.itap.purdue.edu at pub/tools/unix/lsofFAQ. The URL is:
ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/FAQ
/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).)
Lsof was written by Victor A.Abell <[email protected]> of Purdue
University. Many others have contributed to lsof. They're
listed in the 00CREDITS file of the lsof distribution.
The latest distribution of lsof is available via anonymous ftp
from the host lsof.itap.purdue.edu. You'll find the lsof
distribution in the pub/tools/unix/lsof directory.
You can also use this URL:
ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof
Lsof is also mirrored elsewhere. When you access
lsof.itap.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 caution - not all mirrors
always have the latest lsof revision.
Some pre-compiled Lsof executables are available on
lsof.itap.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 distribution before sending questions
to the author.
Not all the following manual pages may exist in every UNIX
dialect to which lsof has been ported.
access(2), awk(1), crash(1), fattach(3C), ff(1), fstat(8),
fuser(1), gethostname(2), isprint(3), kill(1), localtime(3),
lstat(2), modload(8), mount(8), netstat(1), ofiles(8L), perl(1),
ps(1), readlink(2), setlocale(3), stat(2), strftime(3), time(2),
uname(1).
This page is part of the lsof (LiSt Open Files) project.
Information about the project can be found at
⟨http://people.freebsd.org/~abe/⟩. If you have a bug report for
this manual page, send it to [email protected]. This page was
obtained from the tarball lsof_4.91_src.tar fetched from
⟨ftp://ftp.fu-berlin.de/pub/unix/tools/lsof/lsof.tar.gz⟩ on
2024-06-14. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
[email protected]
Revision-4.91 LSOF(8)
Pages that refer to this page: fuser(1), lsfd(1), csysdig(8), sysdig(8)
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