$ lsof [option] [command]
-i : ポート番号
-c : プロセス名
-p : PID
-u : ユーザーID
$ lsof -i:80,443
$ lsof -c mysqld
$ lsof -p 376
$ lsof -u ユーザ名
$ lsof /var/log/apache2/access.log
lsof - list open files
lsof [ -?abChKlnNOPRtUvVX ] [ -A A ] [ -c c ] [ +c c ] [ +|-d d ] [ +|-D D ] [ +|-e s ] [ +|-f [cfgGn] ] [ -F
[f] ] [ -g [s] ] [ -i [i] ] [ -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 4.86 lists on its standard output file information about files opened by processes for the fol‐
lowing UNIX dialects:
Apple Darwin 9 and Mac OS X 10.
FreeBSD 4.9 and 6.4 for x86-based systems
FreeBSD 8.2, 9.0 and 10.0 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><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 -email@example.com, -firstname.lastname@example.org, -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 reg‐
ular 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
See the lsof FAQ (The FAQ section gives its location.) for more information on basic and extended
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
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 sup‐
plied in those sources. For example, Linux 2.4.27 and Solaris 9 both limit command name length to 16
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
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 con‐
tains 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
-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 func‐
tions are restricted, they will not appear in the description of the -D option that accompanies -h or
-? option output. See the DEVICE CACHE FILE section and the sections that follow it for more infor‐
mation 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
When available, the b, r, and u functions may be followed by the device cache file's path. The stan‐
dard 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 speci‐
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 struc‐
tured. 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 avail‐
able 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 speci‐
fied 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.)
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 associ‐
ated 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
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
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 pro‐
gram, 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
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
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 IDentifica‐
tion (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 indi‐
cated by ``'' and ``IPv'' 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 par‐
ticipating in AND option selection.
An Internet address is specified in the form (Items in square brackets are optional.):
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 ``'' and ``IPv'', 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
@188.8.131.52 - Internet IPv4 host address 184.108.40.206
@[3ffe:1ebc::1]:1234 - Internet IPv6 host address
3ffe:1ebc::1, port 1234
UDP:who - UDP who service port
TCP@lsof.itap:513 - TCP, port 513 and host name lsof.itap
tcp@foo:1-10,smtp,99 - TCP, ports 1 through 10,
service name smtp, port 99, host name foo
tcp@bar:1-smtp - TCP, ports 1 through smtp, host bar
:time - either TCP, UDP or UDPLITE time service port
-K selects the listing of tasks of processes, on dialects where task reporting is supported. (If help
output - i.e., the output of the -h or -? options - shows this option, then task reporting is sup‐
ported by the dialect.)
When -K and -a are both specified 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 descrip‐
tion of the TID column in the OUTPUT section.)
-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 speci‐
fied (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 hexadeci‐
mal "0x" format - e.g.,
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 suported.)
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 dis‐
abled 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''. The registration information may be a name or number, depending on what the reg‐
istering 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 regis‐
tration 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 speci‐
fied, lsof displays whatever value - size or offset - is appropriate and available for the type of
-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 num‐
ber) to do that. -o o only specifies the number of digits after ``0t'' in either mixed size and off‐
set 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
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 sec‐
tions 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 selec‐
tion. 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.
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
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
Lsof marks the end of each listing: if field output is in progress (the -F, option has been speci‐
fied), the default marker is `m'; otherwise the default marker is ``========''. The marker is fol‐
lowed by a NL character.
The optional "m</fmt><fmt>" argument specifies a format for the marker line. The </fmt><fmt> characters follow‐
ing `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) documenta‐
tion for what may appear in its format specification. Note that when field output is requested with
the -F option, </fmt><fmt> cannot contain the NL format, ``%n''. Note also that when </fmt><fmt> contains spaces
or other characters that affect the shell's interpretation of arguments, </fmt><fmt> must be quoted appro‐
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 supervis‐
ing 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.
When 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 `^'.
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:
Or, for example, to list network files with all UDP states except Idle, use:
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 net‐
work 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>
TF=<tcp flags and values>
WR=<window read length>
WW=</window><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
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 char‐
acters 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><sys /socketvar.h> and
<netinet /tcp_var.h>. Consult those header files for the meaning of the flags, options, states and
``SO='' precedes socket options and values; ``SS='', socket states; and ``TF='', TCP flags and val‐
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:
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-sepa‐
rated 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
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 abso‐
lutely 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 situa‐
tion 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
The -x option may not be supplied without also supplying a +d or +D option.
-X This is a dialect-specific option.
This IBM AIX RISC/System 6000 option requests the reporting of executed text file and shared library
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
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 distri‐
bution for a more complete description of the Stale Segment ID bug, its APAR, and methods for defin‐
ing readx() use when compiling lsof.
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 pro‐
cesses 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 con‐
ditions 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 follow‐
ing 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 sys‐
tem 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,
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 charac‐
ters 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 ALTER‐
NATE 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. (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 sym‐
bols, 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 HASNOSOCK‐
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 HAS‐
DCACHE 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 direc‐
tory - e.g., / or /root. When HASDCACHE is not defined, lsof does not write or attempt to read a device cache
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 sec‐
tion 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
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 environ‐
ment 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,
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 charac‐
ters, 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 infor‐
mation. 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 out‐
put 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 IDentification number, if a task reporting is supported by the dialect and a task is
being listed. (If help output - i.e., the output of the -h or -? options - shows this option,
then task reporting is supported by the dialect.)
A blank TID column indicates a process - i.e., a non-task.
ZONE is the Solaris 10 and higher zone name. This column must be selected with the -z option.
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
`-' if mode unknown and lock
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 ``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)
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
CLRD CL read
DFI defer IND
DFLU data flush
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
KIOC kernel-issued ioctl
LCK has lock
LG large file
MBLK stream message block
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
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
RC file and record locking cache
RSH shared read
RSYN read synchronization
RW read and write access
SL shared lock
SNAP cooked snapshot
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
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><sys /fcntlcom.h>, and </sys><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:
BR the file has been read
BHUP activity stopped by SIGHUP
BW the file has been written
CX close-on-exec (see fcntl(F_SETFD))
LCK lock was applied
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 ker‐
nel 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.);
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 infor‐
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
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
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 avail‐
able) and labels the column SIZE. The -o and -s options are mutually exclusive; they can't both be
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 num‐
bers 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 fol‐
lowed 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 mod‐
ule 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 informa‐
or ``PIPE->'', followed by a Solaris kernel pipe destination address;