lsof(8) — Linux manual page

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LSOF(8)                  System Manager's Manual                  LSOF(8)

NAME         top

       lsof - list open files

SYNOPSIS         top

       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         top

       Lsof revision  lists on its standard output file information about
       files opened by processes for the following UNIX dialects:

       (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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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)         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       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         top

       /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         top

       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         top

       The latest distribution of lsof is available at

              https://github.com/lsof-org/lsof/releases

SEE ALSO         top

       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).

COLOPHON         top

       This page is part of the lsof (LiSt Open Files) project.
       Information about the project can be found at 
       ⟨http://people.freebsd.org/~abe/⟩.  If you have a bug report for
       this manual page, send it to abe@purdue.edu.  This page was
       obtained from the tarball lsof-4.99.4.tar.gz fetched from
       ⟨https://github.com/lsof-org/lsof/releases/⟩ on 2025-02-02.  If
       you discover any rendering problems in this HTML version of the
       page, or you believe there is a better or more up-to-date source
       for the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

                                Revision-                         LSOF(8)

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