LSOF(8) System Manager's Manual LSOF(8)
NAME
lsof - list open files
SYNOPSIS
lsof [ -?abChHlnNOPQRtUvVX ] [ -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]
DESCRIPTION
Lsof revision 4.99.5 lists on its standard output file information
about files opened by processes for the following UNIX dialects:
Apple Darwin 9, Mac OS X 10, macOS 11 and above
FreeBSD 8.2 and above
Linux 2.1.72 and above
NetBSD 1.2 and above
OpenBSD 7.2 and above
Solaris 9, 10 and 11 and above
OpenIndiana 5.11 and above
(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.
OPTIONS
In the absence of any options, lsof lists all open files belonging to
all active processes.
If any list request option is specified, other list requests must be
specifically requested - e.g., if -U is specified for the listing of
UNIX socket files, NFS files won't be listed unless -N is also
specified; or if a user list is specified with the -u option, UNIX
domain socket files, belonging to users not in the list, won't be
listed unless the -U option is also specified.
Normally, list options that are specifically stated are ORed - i.e.,
specifying the -i option without an address and the -ufoo option
produces a listing of all network files OR files belonging to processes
owned by user ``foo''. 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.
fd is a pseudo file descriptor name for specifying the whole range
of possible file descriptor numbers. fd does not appear in FD
column of output.
+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, Linux INET(6)
socket closed in a local host, Linux pseudoterminal files, POSIX
Message Queueue implementation in Linux, and Linux eventfd should
be displayed with endpoint information and the files of the
endpoints should also be displayed.
Note 1: UNIX socket file endpoint information is only available
when the features enabled line of -v output contains uxsockept,
and psudoterminal endpoint information is only available when the
features enabled line contains ptyept.
Note 2: POSIX Message Queue file endpoint information is only
available when mqueue file system is mounted.
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 features enabled line of -v output contains ptyept. In
addition, this feature works on Linux kernels above 4.13.0.
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 features enabled line of -v output contains uxsockept.
INET socket file endpoint information is inserted to the value at
the NAME column in the form
`` -> PID,cmd,FDmode'', where PID, cmd, FD and mode are the same
as with pipe endpoint information. The endpoint information is
available only if the socket is used for local IPC; both endpoints
bind to the same local IPv4 or IPv6 address.
POSIX Message Queue file endpoint information is displayed in the
NAME column in the same form as that of pipe.
eventfd endpoint information is displayed in the NAME column in
the same form as that of pipe. This feature works on Linux kernels
above 5.2.0.
Multiple occurrences of this information can appear in a file's
NAME column.
-E specifies that endpoint supported 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)
Abbrev. Flag in C code (see open(2))
W O_WRONLY
RW O_RDWR
CR O_CREAT
EXCL O_EXCL
NTTY O_NOCTTY
TR O_TRUNC
AP O_APPEND
ND O_NDELAY
SYN O_SYNC
ASYN O_ASYNC
DIR O_DIRECT
DTY O_DIRECTORY
NFLK O_NOFOLLOW
NATM O_NOATIME
DSYN O_DSYNC
RSYN O_RSYNC
LG O_LARGEFILE
CX O_CLOEXEC
TMPF O_TMPFILE
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.
-H directs lsof to print human readable sizes, e.g. 123.4K 456.7M.
-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 or UDPLITE.
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
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 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 (the mapping is commonly learned from /etc/services).
Inhibiting the conversion may make lsof run a little faster. It
is also useful when port name lookup is not working properly.
-Q ignore failed search terms. When lsof is told to search for users
of a file, or for users of a device, or for a specific PID, or for
certain protocols in use by that PID, and so on, lsof will return
an error if any of the search results are empty. The -Q option
will change this behavior so that lsof will instead return a
successful exit code (0) even if any of the search results are
empty. In addition, missing search terms will not be reported to
stderr.
+|-r [t[c<N>][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. `c<N>' is for
specifying the limits of repeating; if the number of iterations
reaches at `<N>', Lsof stops itself.
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.) On Linux this option also prints the
state of UNIX domain sockets.
-t produce terse output comprising only process identifiers (without
a header), so that it is easy to use programmatically. e.g.
# reload anything using old SSL
lsof -t /lib/*/libssl.so.* | xargs -r kill -HUP
# get list of processes and then iterate over them (Bash only)
mapfile -t pids < <(
lsof -wt /var/log/your.log
)
for pid in "${pids[@]}" ; do
your_command -p "$pid"
done
The -t option implies 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 implies 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.
AFS
Lsof supports the recognition of AFS files for these dialects (and AFS
versions):
AIX 4.1.4 (AFS 3.4a)
HP-UX 9.0.5 (AFS 3.4a)
Linux 1.2.13 (AFS 3.3)
Solaris 2.[56] (AFS 3.4a)
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.
SECURITY
Lsof has three features that may cause security concerns. First, its
default compilation mode allows anyone to list all open files with it.
Second, by default it creates a user-readable and user-writable device
cache file in the home directory of the real user ID that executes
lsof. (The list-all-open-files and device cache features may be
disabled when lsof is compiled.) Third, its -k and -m options name
alternate kernel name list or memory files.
Restricting the listing of all open files is controlled by the
compile-time HASSECURITY 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.
OUTPUT
This section describes the information lsof lists for each open file.
See the OUTPUT FOR OTHER PROGRAMS section for additional information on
output that can be processed by another program.
Lsof only outputs printable (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);
ctty character tty;
DEL deleted file;
err FD information error (see NAME column);
fp. Fileport (Darwin);
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;
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;
pd parent directory;
Rnn unknown pregion number (HP-UX);
rtd root directory;
twd per task current working directory;
txt program text (code and data);
v86 VP/ix mapped file;
FD is followed by one of these characters, describing the mode
under which the file is open:
r for read access;
w for write access;
u for read and write access;
space if 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. FD numbers larger than 9999 are
abbreviated to a ``*'' followed by the last three digits. E.g.,
10001 appears as ``*001''
TYPE is the type of the node associated with the file - e.g., VDIR,
VREG, etc.
or ``ax25'' for a Linux AX.25 socket;
or ``a_inode'' for anonymous inode;
or ``icmp'' for an ICMP socket;
or ``inet'' for an Internet domain socket;
or ``ipx'' for an IPX socket;
or ``key'' for an internal key management socket;
or ``lla'' for a HP-UX link level access file;
or ``ndrv'' for a net driver socket;
or ``netlink'' for a netlink socket;
or ``pack'' for a packet socket;
or ``ppp'' for a PPP socket;
or ``raw'' for a raw socket;
or ``raw6'' for a raw IPv6 socket;
or ``rte'' for an AF_ROUTE socket;
or ``sock'' for a socket of unknown domain;
or ``systm'' for a system socket;
or ``unix'' for a UNIX domain socket;
or ``x.25'' for an HP-UX x.25 socket;
or ``ATALK'' for an AppleTalk 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 ``EVENTFD'' for an eventfd;
or ``FIFO'' for a FIFO special file;
or ``FSEVENTS'' for fsevents;
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 ``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 ``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 ``PMPS'' for a /proc/maps file;
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 ``PROCDSC'' for a processor descriptor;
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 ``PSXMQ'' for a POSIX message queue 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 ``SHM'' for a shared memory file;
or ``SMT'' for a shared memory transport file;
or ``STR'' for streams;
or ``STSO'' for a stream socket;
or ``UNKN'' for an unknown file;
or ``UNKNcwd'' for unknown current working directory;
or ``UNKNdel'' for unknown deleted file;
or ``UNKNfd'' for unknown file descriptor;
or ``UNKNmem'' for unknown memory-mapped file;
or ``UNKNrtd'' for unknown root directory;
or ``UNKNtxt'' for unknown program text;
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 ``UNSP'' for an unsupported 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
PATH path
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
TMPF temporary file
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 common.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.
If the -H option is specified, lsof displays file size in human
readable form.
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.
LOCKS
Lsof can't adequately report the wide variety of UNIX dialect file
locks in a single character. What it reports in a single character is
a compromise between the 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.
OUTPUT FOR OTHER PROGRAMS
When the -F option is specified, lsof produces output that is suitable
for processing by another program - e.g, an awk or Perl script, 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. In repeat mode,
the marker (`m') is also produced. 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.
Lsof version from 4.88 to 4.93.2 always produced one more field, the
file descriptor (`f') field. However, lsof in this version doesn't
produce it. This change is for supporting the use case that a user
needs only the PID field, and doesn't need the file descriptor field.
Specify `f' explicitly if you need the field.
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
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 (always selected in repeat mode)
M the task comMand name
n file name, comment, Internet address
N node identifier (ox<hexadecimal>
o file's offset (0t<decimal> or 0x<hexadecimal>, see -o o)
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.
BLOCKS AND TIMEOUTS
Lsof can be blocked by some kernel functions that it uses - lstat(2),
readlink(2), and stat(2). These functions are stalled in the kernel,
for example, when the hosts where mounted NFS file systems reside
become inaccessible.
Lsof attempts to break these blocks with timers and child processes,
but the techniques are not wholly reliable. When lsof does manage to
break a block, it will report the break with an error message. The
messages may be 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.
AVOIDING KERNEL BLOCKS
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.
ALTERNATE DEVICE NUMBERS
On some dialects, when lsof has to break a block because it can't get
information about a mounted file system via the lstat(2) and stat(2)
kernel functions, or because you specified the -b option, lsof can
obtain some of the information it needs - the device number and
possibly the file system type - from the system mount table. When that
is possible, lsof will report the device number it obtained. (You can
suppress the report by specifying the -w option.)
You can assist this process if your mount table is 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 ...''.
KERNEL NAME CACHE
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
SCO OpenServer
SCO|Caldera UnixWare
Solaris
Tru64 UNIX
Lsof can't report path name components for these dialects:
AIX
OpenBSD
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.)
DEVICE CACHE FILE
Examining all members of the /dev (or /devices) node tree with stat(2)
functions can be time consuming. What's more, the information that
lsof needs - device number, inode number, and path - rarely changes.
Consequently, lsof normally maintains an ASCII text file of cached /dev
(or /devices) information (exception: the /proc-based Linux lsof where
it's not needed.) The local system administrator who builds lsof can
control the way the device cache file path is formed, selecting from
these options:
Path from the -D option;
Path from an environment variable;
System-wide path;
Personal path (the default);
Personal path, modified by an environment variable.
Consult the output of the -h, -D? , or -? help options for the current
state of device cache support. The help output lists the default
read-mode device cache file path that is in effect for the current
invocation of lsof. The -D? option output lists the read-only and
write device cache file paths, the names of any applicable environment
variables, and the personal device cache path format.
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.
LSOF PERMISSIONS THAT AFFECT DEVICE CACHE FILE ACCESS
Two permissions of the lsof executable affect its ability to access
device cache files. The permissions are set by the local system
administrator when lsof is installed.
The first and rarer permission is setuid-root. It comes into effect
when lsof is executed; its effective UID is then root, while its real
(i.e., that of the logged-on user) UID is not. The lsof distribution
recommends that versions for these dialects run setuid-root.
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
OpenBSD 2.[89] and 3.[0-9] for x86-based systems
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
DEVICE CACHE FILE PATH FROM THE -D OPTION
The -D option provides limited means for specifying the device cache
file path. Its ? function will report the read-only and write device
cache file paths that lsof will use.
When the -D b, r, and u functions are available, you can use them to
request that the cache file be built in a 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.
DEVICE CACHE PATH FROM AN ENVIRONMENT VARIABLE
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.
SYSTEM-WIDE DEVICE CACHE PATH
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).
PERSONAL DEVICE CACHE PATH (DEFAULT)
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.
MODIFIED PERSONAL DEVICE CACHE PATH
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.
DIAGNOSTICS
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. If the -Q option is specified, lsof will ignore any search item
failures and only return an error if something unusual and
unrecoverable happened.
It returns a zero (0) if no errors were detected and if either the -Q
option was specified or 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.
EXAMPLES
For a more extensive set of examples, documented more fully, see the
00QUICKSTART file of the lsof distribution.
To list all open files, use:
lsof
To list all open Internet, x.25 (HP-UX), and UNIX domain files, use:
lsof -i -U
To list all open IPv4 network files in use by the process whose PID is
1234, use:
lsof -i 4 -a -p 1234
If it's okay for PID 1234 to not exist, or for PID 1234 to not have any
open IPv4 network files, add -Q :
lsof -Q -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 without worrying if there
are none, use:
lsof -Q /u/abe/foo
To take action only if a process has /u/abe/foo open, use:
lsof /u/abe/foo echo "still in use"
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 -i@128.210.15.17
To find an IP version 6 socket file (when the UNIX dialect supports
IPv6) by its associated numeric colon-form address, use:
lsof -i@[0:1:2:3:4:5:6:7]
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 ===="
BUGS
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[cfn] option is not supported under /proc-based Linux lsof,
because it doesn't read kernel structures from kernel memory.
ENVIRONMENT
Lsof may access these environment variables.
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.
FAQ
Frequently-asked questions and their answers (an FAQ) are available in
the 00FAQ file of the lsof distribution.
That latest version of the file is found at:
https://github.com/lsof-org/lsof/blob/master/00FAQ
FILES
/dev/kmem kernel virtual memory device
/dev/mem physical memory device
/dev/swap system paging device
.lsof_hostname
lsof's device cache file (The suffix, hostname, is the
first component of the host's name returned by
gethostname(2).)
AUTHORS
Lsof was written by Victor A.Abell <abe@purdue.edu> of Purdue
University. Since version 4.93.0, the lsof-org team at GitHub
maintains lsof. Many others have contributed to lsof. They're listed
in the 00CREDITS file of the lsof distribution.
DISTRIBUTION
The latest distribution of lsof is available at
https://github.com/lsof-org/lsof/releases
SEE ALSO
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), open(2), perl(1), ps(1),
readlink(2), setlocale(3), stat(2), strftime(3), time(2), uname(1).
Revision-4.99.5 LSOF(8)
lsof \- list open files