Man Linux: Main Page and Category List

NAME

       lsof - list open files

SYNOPSIS

       lsof [ -?abChlnNOPRtUvVX ] [ -A A ] [ -c c ] [ +c c ] [ +|-d d ] [ +|-D
       D ] [ +|-f [cfgGn] ] [ -F [f] ] [ -g [s] ] [ -i [i] ] [ -k k ]  [  +|-L
       [l] ] [ +|-m m ] [ +|-M ] [ -o [o] ] [ -p s ] [ +|-r [t[m<fmt>]] ] [ -s
       [p:s] ] [ -S [t] ] [ -T [t] ] [ -u s ] [ +|-w ] [ -x [fl] ] [ -z [z]  ]
       [ -Z [Z] ] [ -- ] [names]

DESCRIPTION

       Lsof  revision 4.81 lists on its standard output file information about
       files opened by processes for the following UNIX dialects:

            AIX 5.3
            FreeBSD 4.9 for x86-based systems
            FreeBSD 7.0 and 8.0 for AMD64-based systems
            Linux 2.1.72 and above for x86-based systems
            Solaris 9 and 10

       (See the DISTRIBUTION section of this manual page  for  information  on
       how to obtain the latest lsof revision.)

       An  open file may be a regular file, a directory, a block special file,
       a character special file, an executing text  reference,  a  library,  a
       stream  or  a  network  file  (Internet socket, NFS file or UNIX domain
       socket.)  A specific file or all the files in  a  file  system  may  be
       selected by path.

       Instead  of  a  formatted display, lsof will produce output that can be
       parsed by other programs.  See the  -F,  option  description,  and  the
       OUTPUT FOR OTHER PROGRAMS section for more information.

       In  addition to producing a single output list, lsof will run in repeat
       mode.  In repeat mode it will produce output, delay,  then  repeat  the
       output  operation  until stopped with an interrupt or quit signal.  See
       the +|-r [t[m<fmt>]] option description for more information.

OPTIONS

       In the absence of any options, lsof lists all open files  belonging  to
       all active processes.

       If  any  list  request option is specified, other list requests must be
       specifically requested - e.g., if -U is specified for  the  listing  of
       UNIX  socket  files,  NFS  files  won’t  be  listed  unless  -N is also
       specified; or if a user list is specified  with  the  -u  option,  UNIX
       domain  socket  files,  belonging  to  users  not in the list, won’t be
       listed unless the -U option is also specified.

       Normally list options that are specifically stated  are  ORed  -  i.e.,
       specifying  the  -i  option  without  an  address  and the -ufoo option
       produces a listing of all network files OR files belonging to processes
       owned by user ‘‘foo’’.  The exceptions are:

       1)                                                                      the
                                                                               ‘^’
                                                                               (negated)
                                                                               login
                                                                               name
                                                                               or
                                                                               user
                                                                               ID
                                                                               (UID),
                                                                               specified
                                                                               with
                                                                               the
                                                                               -u
                                                                               option;

       2)                                                                      the
                                                                               ‘^’
                                                                               (negated)
                                                                               process
                                                                               ID
                                                                               (PID),
                                                                               specified
                                                                               with
                                                                               the
                                                                               -p
                                                                               option;

       3)                                                                      the
                                                                               ‘^’
                                                                               (negated)
                                                                               process
                                                                               group
                                                                               ID
                                                                               (PGID),
                                                                               specified
                                                                               with
                                                                               the
                                                                               -g
                                                                               option;

       4)                                                                      the
                                                                               ‘^’
                                                                               (negated)
                                                                               command,
                                                                               specified
                                                                               with
                                                                               the
                                                                               -c
                                                                               option;

       5)                                                                      the
                                                                               (’^’)
                                                                               negated
                                                                               TCP
                                                                               or
                                                                               UDP
                                                                               protocol
                                                                               state
                                                                               names,
                                                                               specified
                                                                               with
                                                                               the
                                                                               -s
                                                                               [p:s]
                                                                               option.

       Since they represent exclusions, they  are  applied  without  ORing  or
       ANDing and take effect before any other selection criteria are applied.

       The -a option  may  be  used  to  AND  the  selections.   For  example,
       specifying  -a,  -U,  and  -ufoo produces a listing of only UNIX socket
       files that belong to processes owned by user ‘‘foo’’.

       Caution: the -a option causes all list selection options to  be  ANDed;
       it can’t be used to cause ANDing of selected pairs of selection options
       by placing  it  between  them,  even  though  its  placement  there  is
       acceptable.   Wherever  -a  is  placed,  it  causes  the  ANDing of all
       selection options.

       Items of the same selection set  -  command  names,  file  descriptors,
       network  addresses,  process identifiers, user identifiers, zone names,
       security contexts - are joined in a single ORed set and applied  before
       the  result  participates  in  ANDing.   Thus,  for example, specifying
       -i@aaa.bbb, -i@ccc.ddd, -a, and -ufff,ggg will select  the  listing  of
       files  that  belong to either login ‘‘fff’’ OR ‘‘ggg’’ AND have network
       connections to either host aaa.bbb OR ccc.ddd.

       Options may be grouped together following a single prefix -- e.g.,  the
       option  set  ‘‘-a -b -C’’ may be stated as -abC.  However, since values
       are optional following +|-f, -F, -g, -i, +|-L, -o, +|-r, -s, -S, -T, -x
       and -z.  when you have no values for them be careful that the following
       character isn’t ambiguous.  For example, -Fn might represent the -F and
       -n  options,  or  it  might  represent the n field identifier character
       following the -F option.  When  ambiguity  is  possible,  start  a  new
       option with a ‘-’ character - e.g., ‘‘-F -n’’.  If the next option is a
       file name, follow the possibly ambiguous option  with  ‘‘--’’  -  e.g.,
       ‘‘-F -- name’’.

       Either  the ‘+’ or the ‘-’ prefix may be applied to a group of options.
       Options that don’t take on separate meanings for each prefix - e.g., -i
       - may be grouped under either prefix.  Thus, for example, ‘‘+M -i’’ may
       be stated as ‘‘+Mi’’ and the group  means  the  same  as  the  separate
       options.  Be careful of prefix grouping when one or more options in the
       group does take on separate meanings under different prefixes  -  e.g.,
       +|-M; ‘‘-iM’’ is not the same request as ‘‘-i +M’’.  When in doubt, use
       separate options with appropriate prefixes.

       -? -h    These two equivalent options  select  a  usage  (help)  output
                list.   Lsof  displays a shortened form of this output when it
                detects an error in the options supplied to it, after  it  has
                displayed  messages  explaining  each  error.  (Escape the ‘?’
                character as your shell requires.)

       -a       This option causes list selection  options  to  be  ANDed,  as
                described above.

       -A A     This  option  is available on systems configured for AFS whose
                AFS kernel code is implemented via dynamic modules.  It allows
                the  lsof  user  to  specify  A as an alternate name list file
                where the kernel addresses of the  dynamic  modules  might  be
                found.  See the lsof FAQ (The FAQ section gives its location.)
                for more information about dynamic modules, their symbols, and
                how they affect lsof.

       -b       This  option  causes lsof to avoid kernel functions that might
                block - lstat(2), readlink(2), and stat(2).

                See  the  BLOCKS  AND  TIMEOUTS  and  AVOIDING  KERNEL  BLOCKS
                sections for information on using this option.

       -c c     This  option  selects  the  listing  of  files  for  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     This  option  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       This option 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     This  option  causes  lsof to search for all open instances of
                directory s and the files and directories it contains  at  its
                top  level.   This option 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     This  option  specifies  a  list  of file descriptors (FDs) to
                exclude from or include  in  the  output  listing.   The  file
                descriptors are specified in the comma-separated set s - e.g.,
                ‘‘cwd,1,3’’, ‘‘^6,^2’’.  (There should be  no  spaces  in  the
                set.)

                The  list is an exclusion list if all entries of the set begin
                with ’^’.  It is an inclusion list if  no  entry  begins  with
                ’^’.  Mixed lists are not permitted.

                A  file  descriptor  number range may be in the set as long as
                neither member is empty, both members  are  numbers,  and  the
                ending  member is larger than the starting one - e.g., ‘‘0-7’’
                or ‘‘3-10’’.  Ranges may be specified for  exclusion  if  they
                have  the  ’^’  prefix  -  e.g.,  ‘‘^0-7’’  excludes  all file
                descriptors 0 through 7.

                Multiple file descriptor numbers are joined in a  single  ORed
                set before participating in AND option selection.

                When  there  are  exclusion  and inclusion members in the set,
                lsof reports them as errors and exits with a  non-zero  return
                code.

                See  the  description of File Descriptor (FD) output values in
                the OUTPUT section for more  information  on  file  descriptor
                names.

       +D D     This  option  causes  lsof to search for all open instances of
                directory D and all the files and directories it  contains  to
                its complete depth.

                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     This  option directs lsofs 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.

       +|-f [cfgGn]
                f  by  itself  clarifies  how  path  name  arguments are to be
                interpreted.  When followed by  c,  f,  g,  G,  or  n  in  any
                combination  it  specifies  that  the  listing  of kernel file
                structure information is to  be  enabled  (‘+’)  or  inhibited
                (‘-’).

                Normally  a  path  name  argument is taken to be a file system
                name if it matches a mounted-on  directory  name  reported  by
                mount(8),  or  if  it  represents a block device, named in the
                mount output and associated with  a  mounted  directory  name.
                When +f is specified, all path name arguments will be taken to
                be file system names, and lsof will complain if any  are  not.
                This  can  be  useful,  for example, when the file system name
                (mounted-on device) isn’t a block device.   This  happens  for
                some CD-ROM file systems.

                When  -f  is specified by itself, all path name arguments will
                be taken to be simple files.  Thus, for example,  the  ‘‘-f --
                /’’  arguments direct lsof to search for open files with a ‘/’
                path name, not all open files in the ‘/’ (root) file system.

                Be careful to make sure +f and -f are properly terminated  and
                aren’t  followed  by  a  character  (e.g., of the file or file
                system name) that might be taken as a parameter.  For example,
                use ‘‘--’’ after +f and -f as in these examples.

                     $ lsof +f -- /file/system/name
                     $ lsof -f -- /file/name

                The  listing  of  information  from  kernel  file  structures,
                requested  with  the  +f  [cfgGn]  option  form,  is  normally
                inhibited,  and  is  not  available  in whole or part for some
                dialects - e.g., /proc-based Linux kernels below 2.6.22.  When
                the prefix to f is a plus sign (‘+’), these characters request
                file structure information:

                     c    file structure use count (not Linux)
                     f    file structure address (not Linux)
                     g    file flag abbreviations (Linux 2.6.22 and up)
                     G    file flags in hexadecimal (Linux 2.6.22 and up)
                     n    file structure node address (not Linux)

                When the prefix is minus (‘-’) the same characters disable the
                listing of the indicated values.

                File   structure   addresses,  use  counts,  flags,  and  node
                addresses may be used to detect more readily  identical  files
                inherited  by  child  processes  and identical files in use by
                different processes.  Lsof column  output  can  be  sorted  by
                output  columns  holding  the  values  and  listed to identify
                identical file use, or lsof field output can be parsed  by  an
                AWK or Perl post-filter script, or by a C program.

       -F f     This  option  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]   This option excludes or selects the listing of files  for  the
                processes  whose  optional process group IDentification (PGID)
                numbers are in the comma-separated set s -  e.g.,  ‘‘123’’  or
                ‘‘123,^456’’.  (There should be no spaces in the set.)

                PGID   numbers   that  begin  with  ‘^’  (negation)  represent
                exclusions.

                Multiple PGID numbers are joined in a single ORed  set  before
                participating   in   AND   option  selection.   However,  PGID
                exclusions are applied without ORing or ANDing and take effect
                before other selection criteria are applied.

                The -g option also enables the output display of PGID numbers.
                When specified without a PGID set that’s all it does.

       -i [i]   This option 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  lsofs  -h  or  -?   output.)   Sequentially
                specifying -i4, followed by -i6 is the same as specifying  -i,
                and  vice-versa.   Specifying -i4, or -i6 after -i is the same
                as specifying -i4 or -i6 by itself.

                Multiple addresses (up to a limit of  100)  may  be  specified
                with  multiple  -i  options.   (A  port number or service name
                range is counted as one address.)  They are joined in a single
                ORed set before participating in AND option selection.

                An  Internet address is specified in the form (Items in square
                brackets are optional.):

                [46][protocol][@hostname|hostaddr][:service|port]

                where:
                     46 specifies the IP version, IPv4 or IPv6
                          that applies to the following address.
                          ’6’ may be be specified only if the UNIX
                          dialect supports IPv6.  If neither ’4’ nor
                          ’6’ is specified, the following address
                          applies to all IP versions.
                     protocol is a protocol name - TCP, UDP
                     hostname is an Internet host name.  Unless a
                          specific IP version is specified, open
                          network files associated with host names
                          of all versions will be selected.
                     hostaddr is a numeric Internet IPv4 address in
                          dot form; or an IPv6 numeric address in
                          colon form, enclosed in brackets, if the
                          UNIX dialect supports IPv6.  When an IP
                          version is selected, only its numeric
                          addresses may be specified.
                     service is an /etc/services name - e.g., smtp -
                          or a list of them.
                     port is a port number, or a list of them.

                IPv6 options may be used only if  the  UNIX  dialect  supports
                IPv6.   To  see  if  the  dialect  supports IPv6, run lsof and
                specify the  -h  or  -?   (help)  option.   If  the  displayed
                description   of   the   -i   option   contains  ‘‘[46]’’  and
                ‘‘IPv[46]’’, IPv6 is supported.

                IPv4 host names and addresses may not be specified if  network
                file  selection is limited to IPv6 with -i 6.  IPv6 host names
                and addresses may not be specified if network  file  selection
                is  limited  to  IPv4  with  -i  4.  When an open IPv4 network
                file’s address is mapped in an IPv6 address, the  open  file’s
                type  will be IPv6, not IPv4, and its display will be selected
                by ’6’, not ’4’.

                At least one address component - 4, 6, protocol, ,IR  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     This option specifies a kernel name list file, k, in place  of
                /vmunix,  /mach,  etc.  This option is not available under AIX
                on the IBM RISC/System 6000.

       -l       This option inhibits the conversion  of  user  ID  numbers  to
                login  names.   It  is  also  useful when login name lookup is
                working improperly or slowly.

       +|-L [l] This option enables (‘+’) or disables  (‘-’)  the  listing  of
                file link counts, where they are available - e.g., they aren’t
                available for 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   This option 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  lsofs -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.  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  lsofs  -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.

       -n       This option inhibits the conversion of network numbers to host
                names for network files.  Inhibiting conversion may make  lsof
                run  faster.   It  is also useful when host name lookup is not
                working properly.

       -N       This option selects the listing of NFS files.

       -o       This option directs lsof to display file offset at all  times.
                It  causes  the  SIZE/OFF output 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     This  option  defines  the  number of decimal digits (o) to be
                printed after the ‘‘0t’’ for a file offset before the form  is
                switched to ‘‘0x...’’.  An o value of zero (unlimited) directs
                lsof to use the ‘‘0t’’ form for all offset output.

                This option does NOT direct lsof  to  display  offset  at  all
                times;  specify  -o  (without  a  trailing number) to do that.
                This option only specifies the number of digits  after  ‘‘0t’’
                in  either mixed size and offset or offset-only output.  Thus,
                for example, to direct lsof to display  offset  at  all  times
                with a decimal digit count of 10, use:

                     -o -o 10
                or
                     -oo10

                The  default number of digits allowed after ‘‘0t’’ is normally
                8, but may have been changed by the lsof builder.  Consult the
                description  of  the -o o option in the output of the -h or -?
                option to determine the default that is in effect.

       -O       This option directs lsof to bypass the  strategy  it  uses  to
                avoid  being  blocked  by some kernel operations - i.e., doing
                them in forked child processes.  See the BLOCKS  AND  TIMEOUTS
                and  AVOIDING  KERNEL  BLOCKS sections for more information on
                kernel operations that may block lsof.

                While use of this option will reduce lsof startup overhead, it
                may also cause lsof to hang when the kernel doesn’t respond to
                a function.  Use this option cautiously.

       -p s     This option 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       This  option  inhibits  the conversion of port numbers to port
                names for network files.  Inhibiting the conversion  may  make
                lsof  run  a  little faster.  It is also useful when port name
                lookup is not working properly.

       +|-r [t[m<fmt>]]
                This option puts lsof in repeat mode.  There lsof  lists  open
                files  as selected by other options, delays t seconds (default
                fifteen), then  repeats  the  listing,  delaying  and  listing
                repetitively  until  stopped  by  a  condition  defined by the
                prefix to the option.

                If the prefix is a ‘-’, repeat mode is endless.  Lsof must  be
                terminated with an interrupt or quit signal.

                If  the prefix is ‘+’, repeat mode will end the first cycle no
                open files are listed - and of course  when  lsof  is  stopped
                with  an  interrupt  or  quit  signal.   When repeat mode ends
                because no files are listed, the process  exit  code  will  be
                zero  if  any  open  files were ever listed; one, if none were
                ever listed.

                Lsof marks the end of each listing:  if  field  output  is  in
                progress  (the  -F,  option  has  been specified), the default
                marker is ‘m’; otherwise the default marker  is  ‘‘========’’.
                The marker is followed by a NL character.

                The  optional  "m<fmt>"  argument  specifies  a format for the
                marker  line.   The  <fmt>  characters   following   ‘m’   are
                interpreted  as  a  format  specification  to  the strftime(3)
                function, when both  it  and  the  localtime(3)  function  are
                available in the dialect’s C library.  Consult the strftime(3)
                documentation for what may appear in its format specification.
                Note  that  when field output is requested with the -F option,
                <fmt> cannot contain the NL format, ‘‘%n’’.   Note  also  that
                when <fmt> contains spaces or other characters that affect the
                shell’s interpretation of  arguments,  <fmt>  must  be  quoted
                appropriately.

                Repeat  mode  reduces  lsof  startup  overhead,  so it is more
                efficient to use this mode than to call lsof repetitively from
                a shell script, for example.

                To  use  repeat  mode  most  efficiently,  accompany +|-r with
                specification of other lsof selection options, so  the  amount
                of  kernel  memory access lsof does will be kept to a minimum.
                Options that filter at the process level - e.g., -c,  -g,  -p,
                -u - are the most efficient selectors.

                Repeat  mode is useful when coupled with field output (see the
                -F, option description) and a supervising awk or Perl  script,
                or a C program.

       -R       This   option   directs   lsof  to  list  the  Parent  Process
                IDentification number in the PPID column.

       -s [p:s] s alone directs lsof to display file size at  all  times.   It
                causes the SIZE/OFF output column title to be changed to SIZE.
                If the file does not have a size, nothing is displayed.

                When followed by a protocol name (p), either  TCP  or  UDP,  a
                colon  (‘:’)  and  a comma-separated protocol state name list,
                the option causes open TCP and UDP files  to  be  excluded  if
                their  state name(s) are in the list (s) preceded by a ‘^’; or
                included if their name(s) are not preceded by a ‘^’.

                When an inclusion list is defined,  only  network  files  with
                state  names  in  the list will be present in the lsof output.
                Thus, specifying one state name means that only network  files
                with that lone state name wil 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]   This  option  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]   This   option   controls   the   reporting   of  some  TCP/TPI
                information,  also  reported  by  netstat(1),  following   the
                network  addresses.   In normal output the information appears
                in parentheses,  each  item  except  TCP  or  TPI  state  name
                identified  by  a  keyword,  followed  by  ‘=’, separated from
                others by a single space:

                     <TCP or TPI state name>
                     QR=<read queue length>
                     QS=<send queue length>
                     SO=<socket options and values>
                     SS=<socket states>
                     TF=<TCP flags and values>
                     WR=<window read length>
                     WW=<window write length>

                Not all values are reported  for  all  UNIX  dialects.   Items
                values  (when  available) are reported after the item name and
                ’=’.

                When the field output mode is in effect (See OUTPUT FOR  OTHER
                PROGRAMS.)   each  item  appears as a field with a ‘T’ leading
                character.

                -T  with  no  following  key   characters   disables   TCP/TPI
                information reporting.

                -T with following characters selects the reporting of specific
                TCP/TPI information:

                     f    selects reporting of socket options,
                          states and values, and TCP flags and
                          values.
                     q    selects queue length reporting.
                     s    selects connection state reporting.
                     w    selects window size reporting.

                Not all selections are enabled for some UNIX dialects.   State
                may  be  selected for all dialects and is reported by default.
                The -h or -?  help output for the -T  option  will  show  what
                selections may be used with the UNIX dialect.

                When  -T  is used to select information - i.e., it is followed
                by one or more selection characters - the displaying of  state
                is  disabled  by  default,  and it must be explicitly selected
                again in the characters following -T.  (In effect,  then,  the
                default  is equivalent to -Ts.)  For example, if queue lengths
                and state are desired, use -Tqs.

                Socket options, socket states, some socket values,  TCP  flags
                and  one TCP value may be reported (when available in the UNIX
                dialect) in the form of the names that commonly  appear  after
                SO_,  so_,  SS_, TCP_  and TF_ in the dialect’s header files -
                most    often    <sys/socket.h>,     <sys/socketvar.h>     and
                <netinet/tcp_var.h>.   Consult  those  header  files  for  the
                meaning of the flags, options, states and values.

                ‘‘SO=’’ precedes socket options and  values;  ‘‘SS=’’,  socket
                states; and ‘‘TF=’’, TCP flags and values.

                If  a flag or option has a value, the value will follow an ’=’
                and  the  name  --   e.g.,   ‘‘SO=LINGER=5’’,   ‘‘SO=QLIM=5’’,
                ‘‘TF=MSS=512’’.  The following seven values may be reported:

                     Name
                     Reported  Description (Common Symbol)

                     KEEPALIVE keep alive time (SO_KEEPALIVE)
                     LINGER    linger time (SO_LINGER)
                     MSS       maximum segment size (TCP_MAXSEG)
                     PQLEN     partial listen queue connections
                     QLEN      established listen queue connections
                     QLIM      established listen queue limit
                     RCVBUF    receive buffer length (SO_RCVBUF)
                     SNDBUF    send buffer length (SO_SNDBUF)

                Details  on what socket options and values, socket states, and
                TCP flags and values may  be  displayed  for  particular  UNIX
                dialects  may be found in the answer to the ‘‘Why doesn’t lsof
                report socket options, socket states, and TCP flags and values
                for  my  dialect?’’  and ‘‘Why doesn’t lsof report the partial
                listen queue connection count for my dialect?’’  questions  in
                the lsof FAQ (The FAQ section gives its location.)

       -t       This  option  specifies  that lsof should produce terse output
                with process identifiers only and no header -  e.g.,  so  that
                the  output  may be piped to kill(1).  This option selects the
                -w option.

       -u s     This option selects the listing of files for  the  user  whose
                login  names or user ID numbers are in the comma-separated set
                s - e.g., ‘‘abe’’,  or  ‘‘548,root’’.   (There  should  be  no
                spaces in the set.)

                Multiple login names or user ID numbers are joined in a single
                ORed set before participating in AND option selection.

                If a login name or user ID is preceded by a ‘^’, it becomes  a
                negation - i.e., files of processes owned by the login name or
                user ID will never be listed.  A negated login name or user ID
                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       This option selects the listing of UNIX domain socket files.

       -v       This  option  selects the listing of lsof version information,
                including:  revision  number;  when  the   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       This option directs lsof to indicate the items it was asked to
                list and failed to find - command names, file names,  Internet
                addresses  or  files, login names, NFS files, PIDs, PGIDs, and
                UIDs.

                When  other  options  are  ANDed   to   search   options,   or
                compile-time  options restrict the listing of some files, lsof
                may not report that it failed to find a search  item  when  an
                ANDed  option  or  compile-time option prevents the listing of
                the open file containing the located search item.

                For example, ‘‘lsof -V -iTCP@foobar -a -d 999’’ may not report
                a  failure  to locate open files at ‘‘TCP@foobar’’ and may not
                list any, if none have a file descriptor  number  of  999.   A
                similar     situation     arises    when    HASSECURITY    and
                HASNOSOCKSECURITY are defined at compile time and they prevent
                the listing of open files.

       +|-w     Enables  (+)  or  disables  (-)  the  suppression  of  warning
                messages.

                The lsof builder may choose to have warning messages  disabled
                or  enabled  by default.  The default warning message state is
                indicated in the output of the -h or  -?   option.   Disabling
                warning  messages  when  they are already disabled or enabling
                them when already enabled is acceptable.

                The -t option selects the -w option.

       -x  [fl] This option 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.
                This  option  and  ’Z’  field  output  character  support  are
                inhibited when  SELinux  is  disabled  in  the  running  Linux
                kernel.  See OUTPUT FOR OTHER PROGRAMS for more information on
                the ’Z’ field output character.

                Without a following  argument  -  e.g.,  NO  Z  -  the  option
                specifies  that  security  contexts  are  to  be listed in the
                SECURITY-CONTEXT output column.

                The -Z option may be followed by a wildcard  security  context
                name,  Z.   That  causes  lsof  to  list  only  open files for
                processes in that security context.  Multiple -Z Z option  and
                argument  pairs  may  be  specified to form a list of security
                contexts.  Any open file of any process in any of the security
                contexts will be listed, subject to other conditions specified
                by other options and arguments.  Note that Z can be  A:B:C  or
                *:B:C or A:B:* or *:*:C to match against the A:B:C context.

       --       The  double minus sign option is a marker that signals the end
                of the keyed options.  It may be used, for example,  when  the
                first file name begins with a minus sign.  It may also be used
                when the absence of a value for the last keyed option must  be
                signified  by  the  presence  of a minus sign in the following
                option and before the start of the file names.

       names    These are path names of  specific  files  to  list.   Symbolic
                links  are  resolved  before  use.   The  first  name  may  be
                separated from the preceding options with the ‘‘--’’ option.

                If a name is the mounted-on directory of a file system or  the
                device  of  the file system, lsof will list all the files open
                on the file system.  To be considered a file system, the  name
                must  match a mounted-on directory name in mount(8) output, or
                match the name of a block device associated with a  mounted-on
                directory  name.  The +|-f option may be used to force lsof to
                consider a name a file system identifier (+f) or a simple file
                (-f).

                If  name  is  a path to a directory that is not the mounted-on
                directory name of a file system,  it  is  treated  just  as  a
                regular  file  is treated - i.e., its listing is restricted to
                processes that have it open as a file or as a process-specific
                directory,  such as the root or current working directory.  To
                request that lsof look for open files inside a directory name,
                use the +d s and +D D options.

                If  a name is the base name of a family of multiplexed files -
                e. g, AIX’s /dev/pt[cs] - lsof will list  all  the  associated
                multiplexed  files  on  the  device  that  are  open  -  e.g.,
                /dev/pt[cs]/1, /dev/pt[cs]/2, etc.

                If a name is a UNIX domain  socket  name,  lsof  will  usually
                search for it by the characters of the name alone - exactly as
                it  is  specified  and  is  recorded  in  the  kernel   socket
                structure.   (See  the next paragraph for an exception to that
                rule for Linux.)  Specifying a relative path - e.g., ./file  -
                in place of the file’s absolute path - e.g., /tmp/file - won’t
                work because lsof must match the characters you  specify  with
                what it finds in the kernel UNIX domain socket structures.

                If a name is a Linux UNIX domain socket name, in one case lsof
                is able to search for it  by  its  device  and  inode  number,
                allowing  name  to be a relative path.  The case requires that
                the absolute path -- i.e., one beginning with a slash (’/’) be
                used  by  the  process  that  created the socket, and hence be
                stored in the /proc/net/unix file; and it requires  that  lsof
                be  able  to  obtain  the  device and node numbers of both the
                absolute  path  in  /proc/net/unix  and  name  via  successful
                stat(2)  system  calls.   When  those conditions are met, lsof
                will be able to search for the UNIX domain  socket  when  some
                path to it is is specified in name.  Thus, for example, if the
                path is /dev/log, and an lsof search  is  initiated  when  the
                working directory is /dev, then name could be ./log.

                If  a name is none of the above, lsof will list any open files
                whose device and inode match that of the specified path  name.

                If  you  have also specified the -b option, the only names you
                may safely specify are file systems for which your mount table
                supplies  alternate  device  numbers.  See the AVOIDING KERNEL
                BLOCKS  and  ALTERNATE  DEVICE  NUMBERS  sections   for   more
                information.

                Multiple  file  names  are  joined in a single ORed set before
                participating in AND option selection.

AFS

       Lsof supports the recognition of AFS files for these dialects (and  AFS
       versions):

            AIX 4.1.4 (AFS 3.4a)
            HP-UX 9.0.5 (AFS 3.4a)
            Linux 1.2.13 (AFS 3.3)
            Solaris 2.[56] (AFS 3.4a)

       It may recognize AFS files on other versions of these dialects, but has
       not been tested there.  Depending on how AFS is implemented,  lsof  may
       recognize  AFS  files  in  other  dialects,  or  may  have difficulties
       recognizing AFS files in the supported dialects.

       Lsof may have trouble identifying all aspects of AFS files in supported
       dialects  when  AFS  kernel  support is implemented via dynamic modules
       whose addresses do not appear in the kernel’s variable name  list.   In
       that  case,  lsof  may  have to guess at the identity of AFS files, and
       might not be able to obtain volume information from the kernel that  is
       needed  for  calculating  AFS  volume  node  numbers.   When lsof can’t
       compute volume node numbers, it reports blank in the NODE column.

       The -A A option is available in some dialect  implementations  of  lsof
       for specifying the name list file where dynamic module kernel addresses
       may be found.  When this option is available, it will be listed in  the
       lsof help output, presented in response to the -h or -?

       See  the  lsof  FAQ  (The  FAQ  section  gives its location.)  for more
       information about dynamic modules, their symbols, and how  they  affect
       lsof options.

       Because AFS path lookups don’t seem to participate in the kernel’s name
       cache operations, lsof can’t identify  path  name  components  for  AFS
       files.

SECURITY

       Lsof  has  three features that may cause security concerns.  First, its
       default compilation mode allows anyone to list all open files with  it.
       Second,  by default it creates a user-readable and user-writable device
       cache file in the home directory of the  real  user  ID  that  executes
       lsof.   (The  list-all-open-files  and  device  cache  features  may be
       disabled when lsof is compiled.)  Third, its -k  and  -m  options  name
       alternate kernel name list or memory files.

       Restricting  the  listing  of  all  open  files  is  controlled  by the
       compile-time   HASSECURITY   and   HASNOSOCKSECURITY   options.    When
       HASSECURITY  is defined, lsof will allow only the root user to list all
       open files.  The non-root user may list only open  files  of  processes
       with  the same user IDentification number as the real user ID number of
       the lsof process (the one that its user logged on with).

       However, if HASSECURITY and HASNOSOCKSECURITY are both defined,  anyone
       may  list  open  socket  files,  provided they are selected with the -i
       option.

       When HASSECURITY is not defined, anyone may list all open files.

       Help output, presented in response to the -h or -?  option,  gives  the
       status of the HASSECURITY and HASNOSOCKSECURITY definitions.

       See  the Security section of the 00README file of the lsof distribution
       for  information  on   building   lsof   with   the   HASSECURITY   and
       HASNOSOCKSECURITY options enabled.

       Creation and use of a user-readable and user-writable device cache file
       is controlled by the compile-time HASDCACHE  option.   See  the  DEVICE
       CACHE  FILE  section and the sections that follow it for details on how
       its path is formed.  For security considerations  it  is  important  to
       note  that  in the default lsof distribution, if the real user ID under
       which lsof is executed is root, the device cache file will  be  written
       in  root’s  home  directory  - e.g., / or /root.  When HASDCACHE is not
       defined, lsof does not write or attempt to read a device cache file.

       When HASDCACHE is defined, the lsof help output, presented in  response
       to the -h, -D?, or -?  options, will provide device cache file handling
       information.  When HASDCACHE is not defined, the -h or -?  output  will
       have no -D option description.

       Before  you  decide to disable the device cache file feature - enabling
       it improves the performance of lsof by reducing the startup overhead of
       examining  all the nodes in /dev (or /devices) - read the discussion of
       it in the 00DCACHE file of the lsof distribution and the lsof FAQ  (The
       FAQ section gives its location.)

       WHEN  IN DOUBT, YOU CAN TEMPORARILY DISABLE THE USE OF THE DEVICE CACHE
       FILE WITH THE -Di OPTION.

       When lsof user declares alternate kernel name list or memory files with
       the  -k  and  -m options, lsof checks the user’s authority to read them
       with access(2).  This is intended to  prevent  whatever  special  power
       lsofs modes might confer on it from letting it read files not normally
       accessible via the authority of the real user ID.

OUTPUT

       This section describes the information lsof lists for each  open  file.
       See the OUTPUT FOR OTHER PROGRAMS section for additional information on
       output that can be processed by another program.

       Lsof  only  outputs  printable  (declared  so  by  isprint(3))  8   bit
       characters.   Non-printable  characters  are  printed  in  one of three
       forms: the C ‘‘\[bfrnt]’’ form; the control character ‘^’  form  (e.g.,
       ‘‘^@’’); or hexadecimal leading ‘‘\x’’ form (e.g., ‘‘\xab’’).  Space is
       non-printable in the COMMAND column (‘‘\x20’’) and printable elsewhere.

       For  some  dialects  -  if  HASSETLOCALE  is  defined  in the dialect’s
       machine.h header file - lsof will print the extended 8  bit  characters
       of  a  language  locale.   The lsof process must be supplied a language
       locale environment variable (e.g., LANG) whose value represents a known
       language  locale  in  which  the  extended  characters  are  considered
       printable  by  isprint(3).   Otherwise  lsof  considers  the   extended
       characters  non-printable  and  prints  them according to its rules for
       non-printable  characters,  stated  above.   Consult   your   dialect’s
       setlocale(3) man page for the names of other environment variables that
       may be used in place of LANG - e.g., LC_ALL, LC_CTYPE, etc.

       Lsofs  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.

       ZONE       is the Solaris 10 and higher zone name.  This column must be
                  selected with the -z option.

       SECURITY-CONTEXT
                  is  the  SELinux  security  context.   This  column  must be
                  selected with the -Z option.  Note that  the  -Z  option  is
                  inhibited  when  SELinux  is  disabled  in the running Linux
                  kernel.

       PPID       is the Parent Process IDentification number of the  process.
                  It  is only displayed when the -R option has been specified.

       PGID       is the process group IDentification number  associated  with
                  the  process.   It  is only displayed when the -g option has
                  been specified.

       USER       is the user ID number or login name of the user to whom  the
                  process  belongs,  usually  the  same  as reported by ps(1).
                  However, on Linux USER is the user ID number or  login  that
                  owns  the  directory  in  /proc where lsof finds information
                  about the process.  Usually that is the same value  reported
                  by  ps(1),  but  may differ when the process has changed its
                  effective user ID.   (See  the  -l  option  description  for
                  information  on  when  a  user  ID  number  or login name is
                  displayed.)

       FD         is the File Descriptor number of the file or:

                       cwd  current working directory;
                       Lnn  library references (AIX);
                       err  FD information error (see NAME column);
                       jld  jail directory (FreeBSD);
                       ltx  shared library text (code and data);
                       Mxx  hex memory-mapped type number xx.
                       m86  DOS Merge mapped file;
                       mem  memory-mapped file;
                       mmap memory-mapped device;
                       pd   parent directory;
                       rtd  root directory;
                       tr   kernel trace file (OpenBSD);
                       txt  program text (code and data);
                       v86  VP/ix mapped file;

                  FD is followed by one of these  characters,  describing  the
                  mode under which the file is open:

                       r for read access;
                       w for write access;
                       u for read and write access;
                       space if mode unknown and no lock
                            character follows;
                       ‘-’ if mode unknown and lock
                            character follows.

                  The  mode  character  is  followed  by  one  of  these  lock
                  characters, describing the type of lock applied to the file:

                       N for a Solaris NFS lock of unknown type;
                       r for read lock on part of the file;
                       R for a read lock on the entire file;
                       w for a write lock on part of the file;
                       W for a write lock on the entire file;
                       u for a read and write lock of any length;
                       U for a lock of unknown type;
                       x  for an SCO OpenServer Xenix lock on part      of the
                  file;
                       X for an SCO OpenServer Xenix lock on  the       entire
                  file;
                       space if there is no lock.

                  See  the  LOCKS  section  for  more  information on the lock
                  information character.

                  The FD  column  contents  constitutes  a  single  field  for
                  parsing in post-processing scripts.

       TYPE       is  the  type  of  the node associated with the file - e.g.,
                  GDIR, GREG, VDIR, VREG, etc.

                  or ‘‘IPv4’’ for an IPv4 socket;

                  or ‘‘IPv6’’ for an open IPv6 network  file  -  even  if  its
                  address is IPv4, mapped in an IPv6 address;

                  or ‘‘ax25’’ for a Linux AX.25 socket;

                  or ‘‘inet’’ for an Internet domain socket;

                  or ‘‘lla’’ for a HP-UX link level access file;

                  or ‘‘rte’’ for an AF_ROUTE socket;

                  or ‘‘sock’’ for a socket of unknown domain;

                  or ‘‘unix’’ for a UNIX domain socket;

                  or ‘‘x.25’’ for an HP-UX x.25 socket;

                  or ‘‘BLK’’ for a block special file;

                  or ‘‘CHR’’ for a character special file;

                  or ‘‘DEL’’ for a Linux map file that has been deleted;

                  or ‘‘DIR’’ for a directory;

                  or ‘‘DOOR’’ for a VDOOR file;

                  or ‘‘FIFO’’ for a FIFO special file;

                  or ‘‘KQUEUE’’ for a BSD style kernel event queue file;

                  or ‘‘LINK’’ for a symbolic link file;

                  or ‘‘MPB’’ for a multiplexed block file;

                  or ‘‘MPC’’ for a multiplexed character file;

                  or  ‘‘NOFD’’ for a Linux /proc/<PID>/fd directory that can’t
                  be opened -- the directory path appears in the NAME  column,
                  followed by an error message;

                  or ‘‘PAS’’ for a /proc/as file;

                  or ‘‘PAXV’’ for a /proc/auxv file;

                  or ‘‘PCRE’’ for a /proc/cred file;

                  or ‘‘PCTL’’ for a /proc control file;

                  or ‘‘PCUR’’ for the current /proc process;

                  or ‘‘PCWD’’ for a /proc current working directory;

                  or ‘‘PDIR’’ for a /proc directory;

                  or ‘‘PETY’’ for a /proc executable type (etype);

                  or ‘‘PFD’’ for a /proc file descriptor;

                  or ‘‘PFDR’’ for a /proc file descriptor directory;

                  or ‘‘PFIL’’ for an executable /proc file;

                  or ‘‘PFPR’’ for a /proc FP register set;

                  or ‘‘PGD’’ for a /proc/pagedata file;

                  or ‘‘PGID’’ for a /proc group notifier file;

                  or ‘‘PIPE’’ for pipes;

                  or ‘‘PLC’’ for a /proc/lwpctl file;

                  or ‘‘PLDR’’ for a /proc/lpw directory;

                  or ‘‘PLDT’’ for a /proc/ldt file;

                  or ‘‘PLPI’’ for a /proc/lpsinfo file;

                  or ‘‘PLST’’ for a /proc/lstatus file;

                  or ‘‘PLU’’ for a /proc/lusage file;

                  or ‘‘PLWG’’ for a /proc/gwindows file;

                  or ‘‘PLWI’’ for a /proc/lwpsinfo file;

                  or ‘‘PLWS’’ for a /proc/lwpstatus file;

                  or ‘‘PLWU’’ for a /proc/lwpusage file;

                  or ‘‘PLWX’’ for a /proc/xregs file’

                  or ‘‘PMAP’’ for a /proc map file (map);

                  or ‘‘PMEM’’ for a /proc memory image file;

                  or ‘‘PNTF’’ for a /proc process notifier file;

                  or ‘‘POBJ’’ for a /proc/object file;

                  or ‘‘PODR’’ for a /proc/object directory;

                  or  ‘‘POLP’’  for  an  old format /proc light weight process
                  file;

                  or ‘‘POPF’’ for an old format /proc PID file;

                  or ‘‘POPG’’ for an old format /proc page data file;

                  or ‘‘PORT’’ for a SYSV named pipe;

                  or ‘‘PREG’’ for a /proc register file;

                  or ‘‘PRMP’’ for a /proc/rmap file;

                  or ‘‘PRTD’’ for a /proc root directory;

                  or ‘‘PSGA’’ for a /proc/sigact file;

                  or ‘‘PSIN’’ for a /proc/psinfo file;

                  or ‘‘PSTA’’ for a /proc status file;

                  or ‘‘PSXSEM’’ for a POSIX semaphore file;

                  or ‘‘PSXSHM’’ for a POSIX shared memory file;

                  or ‘‘PUSG’’ for a /proc/usage file;

                  or ‘‘PW’’ for a /proc/watch file;

                  or ‘‘PXMP’’ for a /proc/xmap file;

                  or ‘‘REG’’ for a regular file;

                  or ‘‘SMT’’ for a shared memory transport file;

                  or ‘‘STSO’’ for a stream socket;

                  or ‘‘UNNM’’ for an unnamed type file;

                  or ‘‘XNAM’’ for an OpenServer Xenix special file of  unknown
                  type;

                  or ‘‘XSEM’’ for an OpenServer Xenix semaphore file;

                  or ‘‘XSD’’ for an OpenServer Xenix shared data file;

                  or  the  four  type  number octets if the corresponding name
                  isn’t known.

       FILE-ADDR  contains the kernel file structure address when f  has  been
                  specified to +f;

       FCT        contains  the  file  reference  count  from  the kernel file
                  structure when c has been specified to +f;

       FILE-FLAG  when g or G has been specified to +f,  this  field  contains
                  the  contents  of  the  f_flag[s]  member of the kernel file
                  structure and the kernel’s per-process open file  flags  (if
                  available);  ‘G’ causes them to be displayed in hexadecimal;
                  ‘g’, as short-hand names; two lists may  be  displayed  with
                  entries  separated  by  commas,  the  lists  separated  by a
                  semicolon (‘;’); the first list may contain short-hand names
                  for f_flag[s] values from the following table:

                       AIO       asynchronous I/O (e.g., FAIO)
                       AP        append
                       ASYN      asynchronous I/O (e.g., FASYNC)
                       BAS       block, test, and set in use
                       BKIU      block if in use
                       BL        use block offsets
                       BSK       block seek
                       CA        copy avoid
                       CIO       concurrent I/O
                       CLON      clone
                       CLRD      CL read
                       CR        create
                       DF        defer
                       DFI       defer IND
                       DFLU      data flush
                       DIR       direct
                       DLY       delay
                       DOCL      do clone
                       DSYN      data-only integrity
                       DTY       must be a directory
                       EVO       event only
                       EX        open for exec
                       EXCL      exclusive open
                       FSYN      synchronous writes
                       GCDF      defer during unp_gc() (AIX)
                       GCMK      mark during unp_gc() (AIX)
                       GTTY      accessed via /dev/tty
                       HUP       HUP in progress
                       KERN      kernel
                       KIOC      kernel-issued ioctl
                       LCK       has lock
                       LG        large file
                       MBLK      stream message block
                       MK        mark
                       MNT       mount
                       MSYN      multiplex synchronization
                       NATM      don’t update atime
                       NB        non-blocking I/O
                       NBDR      no BDRM check
                       NBIO      SYSV non-blocking I/O
                       NBF       n-buffering in effect
                       NC        no cache
                       ND        no delay
                       NDSY      no data synchronization
                       NET       network
                       NFLK      don’t follow links
                       NMFS      NM file system
                       NOTO      disable background stop
                       NSH       no share
                       NTTY      no controlling TTY
                       OLRM      OLR mirror
                       PAIO      POSIX asynchronous I/O
                       PP        POSIX pipe
                       R         read
                       RC        file and record locking cache
                       REV       revoked
                       RSH       shared read
                       RSYN      read synchronization
                       RW        read and write access
                       SL        shared lock
                       SNAP      cooked snapshot
                       SOCK      socket
                       SQSH      Sequent shared set on open
                       SQSV      Sequent SVM set on open
                       SQR       Sequent set repair on open
                       SQS1      Sequent full shared open
                       SQS2      Sequent partial shared open
                       STPI      stop I/O
                       SWR       synchronous read
                       SYN       file integrity while writing
                       TCPM      avoid TCP collision
                       TR        truncate
                       W         write
                       WKUP      parallel I/O synchronization
                       WTG       parallel I/O synchronization
                       VH        vhangup pending
                       VTXT      virtual text
                       XL        exclusive lock

                  this  list of names was derived from F* #define’s in dialect
                  header  files   <fcntl.h>,   <linux</fs.h>,   <sys/fcntl.c>,
                  <sys/fcntlcom.h>,  and  <sys/file.h>;  see the lsof.h header
                  file for a list showing the correspondence between the above
                  short-hand names and the header file definitions;

                  the second list (after the semicolon) may contain short-hand
                  names for kernel  per-process  open  file  flags  from  this
                  table:

                       ALLC      allocated
                       BR        the file has been read
                       BHUP      activity stopped by SIGHUP
                       BW        the file has been written
                       CLSG      closing
                       CX        close-on-exec (see fcntl(F_SETFD))
                       LCK       lock was applied
                       MP        memory-mapped
                       OPIP      open pending - in progress
                       RSVW      reserved wait
                       SHMT      UF_FSHMAT set (AIX)
                       USE       in use (multi-threaded)

       NODE-ID    (or   INODE-ADDR   for  some  dialects)  contains  a  unique
                  identifier for the file node (usually the  kernel  vnode  or
                  inode  address,  but  also  occasionally  a concatenation of
                  device and node number) when n has been specified to +f;

       DEVICE     contains the device numbers,  separated  by  commas,  for  a
                  character  special, block special, regular, directory or NFS
                  file;

                  or ‘‘memory’’ for a memory  file  system  node  under  Tru64
                  UNIX;

                  or  the address of the private data area of a Solaris socket
                  stream;

                  or a kernel reference address that identifies the file  (The
                  kernel  reference  address  may  be  used  for  FIFO’s,  for
                  example.);

                  or the base address or device name of a Linux  AX.25  socket
                  device.

                  Usually  only the lower thirty two bits of Tru64 UNIX kernel
                  addresses are displayed.

       SIZE, SIZE/OFF, or OFFSET
                  is the size of the file or the  file  offset  in  bytes.   A
                  value  is  displayed in this column only if it is available.
                  Lsof  displays  whatever  value  -  size  or  offset  -   is
                  appropriate  for  the  type  of  the file and the version of
                  lsof.

                  On  some  UNIX  dialects  lsof  can’t  obtain  accurate   or
                  consistent  file  offset  information  from  its kernel data
                  sources, sometimes just for particular kinds of files (e.g.,
                  socket  files.)  In other cases, files don’t have true sizes
                  - e.g., sockets, FIFOs, pipes - so lsof displays  for  their
                  sizes  the  content  amounts it finds in their kernel buffer
                  descriptors (e.g.,  socket  buffer  size  counts  or  TCP/IP
                  window  sizes.)  Consult the lsof FAQ (The FAQ section gives
                  its location.)  for more information.

                  The file  size  is  displayed  in  decimal;  the  offset  is
                  normally  displayed  in  decimal with a leading ‘‘0t’’ if it
                  contains 8 digits or less; in  hexadecimal  with  a  leading
                  ‘‘0x’’  if  it  is  longer than 8 digits.  (Consult the -o o
                  option description for information on when 8  might  default
                  to some other value.)

                  Thus  the  leading ‘‘0t’’ and ‘‘0x’’ identify an offset when
                  the column may contain both a size and an offset (i.e.,  its
                  title is SIZE/OFF).

                  If the -o option is specified, lsof always displays the file
                  offset (or nothing if no offset is available) and labels the
                  column  OFFSET.   The  offset  always  begins with ‘‘0t’’ or
                  ‘‘0x’’ as described above.

                  The lsof user can control the switch from ‘‘0t’’  to  ‘‘0x’’
                  with  the  -o  o  option.   Consult its description for more
                  information.

                  If the -s option is specified, lsof always displays the file
                  size  (or  nothing  if  no size is available) and labels the
                  column SIZE.  The -o and -s options are mutually  exclusive;
                  they can’t both be specified.

                  For  files that don’t have a fixed size - e.g., don’t reside
                  on a disk device - lsof will display appropriate information
                  about  the  current  size  or  position of the file if it is
                  available in the kernel structures that define the file.

       NLINK      contains the file link count when +L has been specified;

       NODE       is the node number of a local file;

                  or the inode number of an NFS file in the server host;

                  or the Internet protocol type - e. g, ‘‘TCP’’;

                  or ‘‘STR’’ for a stream;

                  or ‘‘CCITT’’ for an HP-UX x.25 socket;

                  or the IRQ or inode number of a Linux AX.25 socket device.

       NAME       is the name of the mount point and file system on which  the
                  file resides;

                  or  the  name of a file specified in the names option (after
                  any symbolic links have been resolved);

                  or the name of a character special or block special device;

                  or the local and remote  Internet  addresses  of  a  network
                  file;  the  local  host  name  or IP number is followed by a
                  colon (’:’), the  port,  ‘‘->’’,  and  the  two-part  remote
                  address;  IP  addresses may be reported as numbers or names,
                  depending on the +|-M, -n, and -P  options;  colon-separated
                  IPv6   numbers   are   enclosed  in  square  brackets;  IPv4
                  INADDR_ANY and IPv6 IN6_IS_ADDR_UNSPECIFIED  addresses,  and
                  zero  port  numbers  are represented by an asterisk (’*’); a
                  UDP destination address may be followed  by  the  amount  of
                  time   elapsed  since  the  last  packet  was  sent  to  the
                  destination; TCP, UDP and UDPLITE remote  addresses  may  be
                  followed  by  TCP/TPI  information  in  parentheses  - state
                  (e.g., ‘‘(ESTABLISHED)’’, ‘‘(Unbound)’’), queue  sizes,  and
                  window  sizes  (not  all dialects) - in a fashion similar to
                  what netstat(1) reports; see the -T  option  description  or
                  the  description  of  the  TCP/TPI field in OUTPUT FOR OTHER
                  PROGRAMS for more information  on  state,  queue  size,  and
                  window size;

                  or  the  address  or  name of a UNIX domain socket, possibly
                  including a stream clone device name, a file system object’s
                  path  name,  local and foreign kernel addresses, socket pair
                  information, and a bound vnode address;

                  or the local and remote mount point names of an NFS file;

                  or ‘‘STR’’, followed by the stream name;

                  or a stream character device name, followed  by  ‘‘->’’  and
                  the  stream name or a list of stream module names, separated
                  by ‘‘->’’;

                  or ‘‘STR:’’ followed by the SCO OpenServer stream device and
                  module names, separated by ‘‘->’’;

                  or  system  directory name, ‘‘ -- ’’, and as many components
                  of the path name as lsof can find in the kernel’s name cache
                  for selected dialects (See the KERNEL NAME CACHE section for
                  more information.);

                  or ‘‘PIPE->’’, followed by a Solaris kernel pipe destination
                  address;

                  or  ‘‘COMMON:’’,  followed  by  the vnode device information
                  structure’s device name, for a Solaris common vnode;

                  or the address family, followed by a slash  (‘/’),  followed
                  by  fourteen  comma-separated  bytes  of  a non-Internet raw
                  socket address;

                  or the HP-UX x.25 local address,  followed  by  the  virtual
                  connection  number  (if any), followed by the remote address
                  (if any);

                  or ‘‘(dead)’’ for disassociated Tru64 UNIX files - typically
                  terminal  files  that  have  been flagged with the TIOCNOTTY
                  ioctl and closed by daemons;

                  or ‘‘rd=<offset>’’ and ‘‘wr=<offset>’’ for the values of the
                  read and write offsets of a FIFO;

                  or  ‘‘clone n:/dev/event’’ for SCO OpenServer file clones of
                  the /dev/event device, where n is the minor device number of
                  the file;

                  or  ‘‘(socketpair:  n)’’ for a Solaris 2.6, 8, 9  or 10 UNIX
                  domain  socket,  created  by  the   socketpair(3N)   network
                  function;

                  or  ‘‘no  PCB’’ for socket files that do not have a protocol
                  block associated  with  them,  optionally  followed  by  ‘‘,
                  CANTSENDMORE’’  if  sending on the socket has been disabled,
                  or ‘‘, CANTRCVMORE’’ if receiving on  the  socket  has  been
                  disabled (e.g., by the shutdown(2) function);

                  or the local and remote addresses of a Linux IPX socket file
                  in the form <net>:[<node>:]<port>, followed  in  parentheses
                  by  the transmit and receive queue sizes, and the connection
                  state;

                  or ‘‘dgram’’ or ‘‘stream’’ for the type UnixWare  7.1.1  and
                  above  in-kernel  UNIX  domain  sockets, followed by a colon
                  (’:’) and the local path name when  available,  followed  by
                  ‘‘->’’  and the remote path name or kernel socket address in
                  hexadecimal when available.

       For dialects that support a ‘‘namefs’’ file system, allowing  one  file
       to   be   attached   to   another   with  fattach(3C),  lsof  will  add
       ‘‘(FA:<address1><direction><address2>)’’   to    the    NAME    column.
       <address1> and <address2> are hexadecimal vnode addresses.  <direction>
       will be ‘‘<-’’ if <address2> has been fattach’ed to  this  vnode  whose
       address  is  <address1>; and ‘‘->’’ if <address1>, the vnode address of
       this vnode, has been  fattach’ed  to  <address2>.   <address1>  may  be
       omitted if it already appears in the DEVICE column.

       Lsof  may  add  two  parenthetical  notes  to  the NAME column for open
       Solaris  10  files:  ‘‘(?)’’  if  lsof  considers  the  path  name   of
       questionable  accuracy;  and  ‘‘(deleted)’’  if  the -X option has been
       specified and lsof detects the open file’s path name has been  deleted.
       Consult  the  lsof  FAQ (The FAQ section gives its location.)  for more
       information on these NAME column additions.

LOCKS

       Lsof can’t adequately report the wide  variety  of  UNIX  dialect  file
       locks  in a single character.  What it reports in a single character is
       a compromise between the information it finds in  the  kernel  and  the
       limitations of the reporting format.

       Moreover, when a process holds several byte level locks on a file, lsof
       only reports the status of the first lock it encounters.  If  it  is  a
       byte level lock, then the lock character will be reported in lower case
       - i.e., ‘r’, ‘w’, or ‘x’  -  rather  than  the  upper  case  equivalent
       reported for a full file lock.

       Generally  lsof  can  only  report  on locks held by local processes on
       local files.  When a local process sets a lock on  a  remotely  mounted
       (e.g.,  NFS)  file,  the  remote  server  host usually records the lock
       state.  One exception is Solaris - at some patch levels of 2.3, and  in
       all  versions  above  2.4,  the  Solaris  kernel records information on
       remote locks in local structures.

       Lsof has trouble reporting locks for some UNIX dialects.   Consult  the
       BUGS section of this manual page or the lsof FAQ (The FAQ section gives
       its location.)  for more information.

OUTPUT FOR OTHER PROGRAMS

       When the -F option is specified, lsof produces output that is  suitable
       for  processing by another program - e.g, an awk or Perl script, or a C
       program.

       Each unit of information is output in a field that is identified with a
       leading character and terminated by a NL (012) (or a NUL (000) if the 0
       (zero) field identifier character is specified.)  The data of the field
       follows  immediately  after  the  field  identification  character  and
       extends to the field terminator.

       It is possible to think of field output as process and  file  sets.   A
       process  set  begins  with a field whose identifier is ‘p’ (for process
       IDentifier (PID)).  It extends to the beginning of the next  PID  field
       or  the beginning of the first file set of the process, whichever comes
       first.  Included in the  process  set  are  fields  that  identify  the
       command,  the  process group IDentification (PGID) number, and the user
       ID (UID) number or login name.

       A file set begins with a  field  whose  identifier  is  ‘f’  (for  file
       descriptor).   It  is followed by lines that describe the file’s access
       mode, lock state, type, device, size, offset, inode, protocol, name and
       stream  module  names.  It extends to the beginning of the next file or
       process set, whichever comes first.

       When the NUL (000) field terminator has been selected with the 0 (zero)
       field  identifier character, lsof ends each process and file set with a
       NL (012) character.

       Lsof always produces one field, the PID (‘p’) field.  All other  fields
       may  be declared optionally in the field identifier character list that
       follows the -F option.  When a field selection character identifies  an
       item  lsof  does  not  normally  list  - e.g., PPID, selected with -R -
       specification of the field character - e.g., ‘‘-FR’’ - also selects the
       listing of the item.

       It is entirely possible to select a set of fields that cannot easily be
       parsed - e.g., if the field descriptor field is not selected, it may be
       difficult  to  identify  file sets.  To help you avoid this difficulty,
       lsof supports the -F option; it selects the output of all  fields  with
       NL  terminators  (the  -F0 option pair selects the output of all fields
       with NUL terminators).  For compatibility reasons neither  -F  nor  -F0
       select the raw device field.

       These  are  the  fields  that  lsof will produce.  The single character
       listed first is the field identifier.

            a    file access mode
            c    process command name (all characters from proc or
                 user structure)
            C    file structure share count
            d    file’s device character code
            D    file’s major/minor device number (0x<hexadecimal>)
            f    file descriptor
            F    file structure address (0x<hexadecimal>)
            G    file flaGs (0x<hexadecimal>; names if +fg follows)
            i    file’s inode number
            k    link count
            l    file’s lock status
            L    process login name
            m    marker between repeated output
            n    file name, comment, Internet address
            N    node identifier (ox<hexadecimal>
            o    file’s offset (decimal)
            p    process ID (always selected)
            g    process group ID
            P    protocol name
            r    raw device number (0x<hexadecimal>)
            R    parent process ID
            s    file’s size (decimal)
            S    file’s stream identification
            t    file’s type
            T    TCP/TPI information, identified by prefixes (the
                 ‘=’ is part of the prefix):
                     QR=<read queue size>
                     QS=<send queue size>
                     SO=<socket options and values> (not all dialects)
                     SS=<socket states> (not all dialects)
                     ST=<connection state>
                     TF=<TCP flags and values> (not all dialects)
                     WR=<window read size>  (not all dialects)
                     WW=<window write size>  (not all dialects)
                 (TCP/TPI information isn’t reported for all supported
                   UNIX dialects. The -h or -? help output for the
                   -T option will show what TCP/TPI reporting can be
                   requested.)
            u    process user ID
            z    Solaris 10 and higher zone name
            Z    SELinux security context (inhibited when SELinux is disabled)
            0    use NUL field terminator character in place of NL
            1-9  dialect-specific field identifiers (The output
                 of -F? identifies the information to be found
                 in dialect-specific fields.)

       You can get on-line help information  on  these  characters  and  their
       descriptions  by  specifying  the  -F?   option  pair.  (Escape the ‘?’
       character as your shell requires.)   Additional  information  on  field
       content can be found in the OUTPUT section.

       As  an  example,  ‘‘-F pcfn’’ will select the process ID (‘p’), command
       name (‘c’), file descriptor (‘f’) and file name (‘n’) fields with an NL
       field terminator character; ‘‘-F pcfn0’’ selects the same output with a
       NUL (000) field terminator character.

       Lsof doesn’t produce all fields for every process  or  file  set,  only
       those  that  are  available.   Some fields are mutually exclusive: file
       device characters and  file  major/minor  device  numbers;  file  inode
       number  and  protocol  name;  file name and stream identification; file
       size and offset.  One or the other member of these  mutually  exclusive
       sets will appear in field output, but not both.

       Normally  lsof ends each field with a NL (012) character.  The 0 (zero)
       field identifier  character  may  be  specified  to  change  the  field
       terminator character to a NUL (000).  A NUL terminator may be easier to
       process with xargs (1), for example, or  with  programs  whose  quoting
       mechanisms  may  not  easily  cope  with the range of characters in the
       field output.  When the NUL field terminator is in use, lsof ends  each
       process and file set with a NL (012).

       Three aids to producing programs that can process lsof field output are
       included in the lsof distribution.  The  first  is  a  C  header  file,
       lsof_fields.h,  that  contains  symbols  for  the  field identification
       characters, indexes for  storing  them  in  a  table,  and  explanation
       strings  that  may  be  compiled  into programs.  Lsof uses this header
       file.

       The second aid is a set of sample scripts that  process  field  output,
       written  in  awk,  Perl  4, and Perl 5.  They’re located in the scripts
       subdirectory of the lsof distribution.

       The third aid is the C library used for the lsof test suite.  The  test
       suite  is  written  in  C and uses field output to validate the correct
       operation of lsof.  The library can be found in the tests/LTlib.c  file
       of  the  lsof  distribution.   The  library  uses  the  first  aid, the
       lsof_fields.h header file.

BLOCKS AND TIMEOUTS

       Lsof can be blocked by some kernel functions that it uses  -  lstat(2),
       readlink(2),  and  stat(2).  These functions are stalled in the kernel,
       for example, when the hosts  where  mounted  NFS  file  systems  reside
       become inaccessible.

       Lsof  attempts  to  break these blocks with timers and child processes,
       but the techniques are not wholly reliable.  When lsof does  manage  to
       break  a  block,  it  will report the break with an error message.  The
       messages may be suppressed with the -t and -w options.

       The default timeout value may be displayed with the -h or  -?   option,
       and it may be changed with the -S [t] option.  The minimum for t is two
       seconds,  but  you  should  avoid  small  values,  since  slow   system
       responsiveness  can  cause  short  timeouts  to expire unexpectedly and
       perhaps stop lsof before it can produce any output.

       When lsof has to break a block during its access of mounted file system
       information,  it  normally  continues,  although  with less information
       available to display about open files.

       Lsof can also be directed to avoid the protection of timers  and  child
       processes   when  using  the  kernel  functions  that  might  block  by
       specifying the -O option.  While this will allow lsof to start up  with
       less overhead, it exposes lsof completely to the kernel situations that
       might block it.  Use this option cautiously.

AVOIDING KERNEL BLOCKS

       You can use the -b option to tell lsof to avoid using kernel  functions
       that would block.  Some cautions apply.

       First,  using  this  option  usually  requires  that your system supply
       alternate device numbers in place of the device numbers that lsof would
       normally  obtain  with  the lstat(2) and stat(2) kernel functions.  See
       the ALTERNATE DEVICE NUMBERS section for more information on  alternate
       device numbers.

       Second,  you can’t specify names for lsof to locate unless they’re file
       system names.  This is because lsof needs to know the device and  inode
       numbers  of  files  listed  with  names in the lsof options, and the -b
       option prevents lsof from obtaining them.  Moreover,  since  lsof  only
       has  device  numbers  for  the  file  systems that have alternates, its
       ability to locate files on  file  systems  depends  completely  on  the
       availability  and  accuracy  of  the  alternates.  If no alternates are
       available, or if they’re incorrect, lsof won’t be able to locate  files
       on the named file systems.

       Third,  if  the names of your file system directories that lsof obtains
       from your system’s mount table are symbolic links, lsof won’t  be  able
       to  resolve  the  links.   This is because the -b option causes lsof to
       avoid the kernel readlink(2)  function  it  uses  to  resolve  symbolic
       links.

       Finally, using the -b option causes lsof to issue warning messages when
       it needs to use the kernel functions that the -b option directs  it  to
       avoid.   You  can  suppress these messages by specifying the -w option,
       but if you do, you won’t see the alternate device numbers  reported  in
       the warning messages.

ALTERNATE DEVICE NUMBERS

       On  some  dialects, when lsof has to break a block because it can’t get
       information about a mounted file system via the  lstat(2)  and  stat(2)
       kernel  functions,  or  because  you  specified the -b option, lsof can
       obtain some of the  information  it  needs  -  the  device  number  and
       possibly the file system type - from the system mount table.  When that
       is possible, lsof will report the device number it obtained.  (You  can
       suppress the report by specifying the -w option.)

       You  can  assist  this process if your mount table is supported with an
       /etc/mtab or /etc/mnttab file that contains an options field by  adding
       a  ‘‘dev=xxxx’’  field  for  mount points that do not have one in their
       options strings.  Note: you must be able to edit the file - i.e.,  some
       mount  tables like recent Solaris /etc/mnttab or Linux /proc/mounts are
       read-only and can’t be modified.

       You may also be able to supply device numbers using the  +m  and  +m  m
       options, provided they are supported by your dialect.  Check the output
       of lsofs -h or -?  options to see if the  +m  and  +m  m  options  are
       available.

       The  ‘‘xxxx’’ portion of the field is the hexadecimal value of the file
       system’s device number.  (Consult the st_dev field of the output of the
       lstat(2) and stat(2) functions for the appropriate values for your file
       systems.)  Here’s an example from a Sun Solaris 2.6 /etc/mnttab  for  a
       file system remotely mounted via NFS:

            nfs  ignore,noquota,dev=2a40001

       There’s an advantage to having ‘‘dev=xxxx’’ entries in your mount table
       file, especially for file systems that  are  mounted  from  remote  NFS
       servers.   When  a  remote  server crashes and you want to identify its
       users by running lsof on one of its clients,  lsof  probably  won’t  be
       able to get output from the lstat(2) and stat(2) functions for the file
       system.  If it can obtain the file  system’s  device  number  from  the
       mount  table,  it will be able to display the files open on the crashed
       NFS server.

       Some dialects that do not use an ASCII /etc/mtab  or  /etc/mnttab  file
       for  the  mount table may still provide an alternative device number in
       their internal mount tables.  This includes AIX, Apple Darwin, FreeBSD,
       NetBSD,  OpenBSD,  and  Tru64  UNIX.   Lsof  knows  how  to  obtain the
       alternative device number for these  dialects  and  uses  it  when  its
       attempt to lstat(2) or stat(2) the file system is blocked.

       If  you’re  not sure your dialect supplies alternate device numbers for
       file systems from its mount table, use this lsof incantation to see  if
       it reports any alternate device numbers:

              lsof -b

       Look  for  standard  error  file warning messages that begin ‘‘assuming
       "dev=xxxx" from ...’’.

KERNEL NAME CACHE

       Lsof is able to examine the kernel’s name cache  or  use  other  kernel
       facilities  (e.g.,  the  ADVFS  4.x  tag_to_path() function under Tru64
       UNIX) on some dialects for most file system types, excluding  AFS,  and
       extract  recently  used path name components from it.  (AFS file system
       path lookups don’t use the kernel’s name cache; some Solaris VxFS  file
       system operations apparently don’t use it, either.)

       Lsof  reports  the complete paths it finds in the NAME column.  If lsof
       can’t report all components in a path, it reports in  the  NAME  column
       the  file system name, followed by a space, two ‘-’ characters, another
       space, and the name components it has located,  separated  by  the  ‘/’
       character.

       When  lsof is run in repeat mode - i.e., with the -r option specified -
       the extent to which it can report path name  components  for  the  same
       file  may  vary  from  cycle  to  cycle.   That’s because other running
       processes can cause the kernel to remove entries from  its  name  cache
       and replace them with others.

       Lsofs  use of the kernel name cache to identify the paths of files can
       lead it to report incorrect components under some circumstances.   This
       can  happen when the kernel name cache uses device and node number as a
       key (e.g., SCO OpenServer) and a key on a rapidly changing file  system
       is  reused.   If the UNIX dialect’s kernel doesn’t purge the name cache
       entry for a file when it is unlinked, lsof may find a reference to  the
       wrong  entry  in  the  cache.   The lsof FAQ (The FAQ section gives its
       location.)  has more information on this situation.

       Lsof can report path name components for these dialects:

            FreeBSD
            HP-UX
            Linux
            NetBSD
            NEXTSTEP
            OpenBSD
            OPENSTEP
            SCO OpenServer
            SCO|Caldera UnixWare
            Solaris
            Tru64 UNIX

       Lsof can’t report path name components for these dialects:

            AIX

       If you want to know why lsof can’t report path name components for some
       dialects, see the lsof FAQ (The FAQ section gives its location.)

DEVICE CACHE FILE

       Examining  all members of the /dev (or /devices) node tree with stat(2)
       functions can be time consuming.  What’s  more,  the  information  that
       lsof needs - device number, inode number, and path - rarely changes.

       Consequently, lsof normally maintains an ASCII text file of cached /dev
       (or /devices) information (exception: the /proc-based Linux lsof  where
       it’s  not  needed.)  The local system administrator who builds lsof can
       control the way the device cache file path is  formed,  selecting  from
       these options:

            Path from the -D option;
            Path from an environment variable;
            System-wide path;
            Personal path (the default);
            Personal path, modified by an environment variable.

       Consult the output of the -h, -D? , or -?  help options for the current
       state of device cache support.   The  help  output  lists  the  default
       read-mode  device  cache  file  path  that is in effect for the current
       invocation of lsof.  The -D?  option output  lists  the  read-only  and
       write  device cache file paths, the names of any applicable environment
       variables, and the personal device cache path format.

       Lsof  can  detect  that  the  current  device  cache  file   has   been
       accidentally or maliciously modified by integrity checks, including the
       computation and verification of a sixteen bit Cyclic  Redundancy  Check
       (CRC)  sum  on  the  file’s contents.  When lsof senses something wrong
       with the file, it issues a warning and attempts to remove  the  current
       cache  file  and create a new copy, but only to a path that the process
       can legitimately write.

       The path from which a lsof process may attempt to read a  device  cache
       file  may  not  be  the  same  as the path to which it can legitimately
       write.  Thus when lsof senses that it needs to update the device  cache
       file,  it may choose a different path for writing it from the path from
       which it read an incorrect or outdated version.

       If available, the -Dr option will inhibit the writing of a  new  device
       cache  file.  (It’s always available when specified without a path name
       argument.)

       When a new device is added to the system, the  device  cache  file  may
       need  to  be  recreated.   Since  lsof compares the mtime of the device
       cache file  with  the  mtime  and  ctime  of  the  /dev  (or  /devices)
       directory, it usually detects that a new device has been added; in that
       case lsof issues a warning message and attempts to rebuild  the  device
       cache file.

       Whenever  lsof writes a device cache file, it sets its ownership to the
       real UID of the executing process, and its permission  modes  to  0600,
       this restricting its reading and writing to the file’s owner.

LSOF PERMISSIONS THAT AFFECT DEVICE CACHE FILE ACCESS

       Two  permissions  of  the  lsof executable affect its ability to access
       device cache files.  The  permissions  are  set  by  the  local  system
       administrator when lsof is installed.

       The  first  and  rarer permission is setuid-root.  It comes into effect
       when lsof is executed; its effective UID is then root, while  its  real
       (i.e.,  that  of the logged-on user) UID is not.  The lsof distribution
       recommends that versions for these dialects run setuid-root.

            HP-UX 11.11 and 11.23
            Linux

       The second and more common permission is setgid.  It comes into  effect
       when  the  effective  group  IDentification  number  (GID)  of the lsof
       process is set to one that can access kernel  memory  devices  -  e.g.,
       ‘‘kmem’’, ‘‘sys’’, or ‘‘system’’.

       An  lsof  process  that  has  setgid  permission usually surrenders the
       permission after it has accessed the kernel memory  devices.   When  it
       does  that,  lsof  can allow more liberal device cache path formations.
       The lsof distribution recommends that versions for these  dialects  run
       setgid and be allowed to surrender setgid permission.

            AIX 5.[12] and 5.3-ML1
            Apple Darwin 7.x Power Macintosh systems
            FreeBSD 4.x, 4.1x, 5.x and [67].x for x86-based systems
            FreeBSD 5.x and [67].x for Alpha, AMD64 and Sparc64-based
                systems
            HP-UX 11.00
            NetBSD 1.[456], 2.x and 3.x for Alpha, x86, and SPARC-based
                systems
            NEXTSTEP 3.[13] for NEXTSTEP architectures
            OpenBSD 2.[89] and 3.[0-9] for x86-based systems
            OPENSTEP 4.x
            SCO OpenServer Release 5.0.6 for x86-based systems
            SCO|Caldera UnixWare 7.1.4 for x86-based systems
            Solaris 2.6, 8, 9 and 10
            Tru64 UNIX 5.1

       (Note: lsof for AIX 5L and above needs setuid-root permission if its -X
       option is used.)

       Lsof for these dialects  does  not  support  a  device  cache,  so  the
       permissions  given  to  the  executable don’t apply to the device cache
       file.

            Linux

DEVICE CACHE FILE PATH FROM THE -D OPTION

       The -D option provides limited means for specifying  the  device  cache
       file  path.  Its ?  function will report the read-only and write device
       cache file paths that lsof will use.

       When the -D b, r, and u functions are available, you can  use  them  to
       request  that the cache file be built in a specific location (b[path]);
       read but not rebuilt (r[path]); or read and rebuilt (u[path]).  The  b,
       r,  and  u  functions  are  restricted under some conditions.  They are
       restricted when the lsof process is setuid-root.   The  path  specified
       with the r function is always read-only, even when it is available.

       The  b,  r,  and  u functions are also restricted when the lsof process
       runs setgid and lsof doesn’t surrender the setgid permission.  (See the
       LSOF  PERMISSIONS  THAT  AFFECT  DEVICE CACHE FILE ACCESS section for a
       list of implementations that  normally  don’t  surrender  their  setgid
       permission.)

       A further -D function, i (for ignore), is always available.

       When  available,  the  b function tells lsof to read device information
       from the kernel with the stat(2) function and build a device cache file
       at the indicated path.

       When  available,  the  r  function  tells lsof to read the device cache
       file, but not update it.  When a  path  argument  accompanies  -Dr,  it
       names  the  device cache file path.  The r function is always available
       when it is specified without a path name  argument.   If  lsof  is  not
       running  setuid-root  and surrenders its setgid permission, a path name
       argument may accompany the r function.

       When available, the u function tells lsof to attempt to  read  and  use
       the  device  cache file.  If it can’t read the file, or if it finds the
       contents of the file incorrect or outdated, it  will  read  information
       from  the kernel, and attempt to write an updated version of the device
       cache file, but only to a path it considers  legitimate  for  the  lsof
       process effective and real UIDs.

DEVICE CACHE PATH FROM AN ENVIRONMENT VARIABLE

       Lsofs  second  choice for the device cache file is the contents of the
       LSOFDEVCACHE environment variable.  It avoids this choice if  the  lsof
       process is setuid-root, or the real UID of the process is root.

       A  further  restriction  applies to a device cache file path taken from
       the LSOFDEVCACHE environment variable: lsof will  not  write  a  device
       cache file to the path if the lsof process doesn’t surrender its setgid
       permission.  (See the LSOF PERMISSIONS THAT AFFECT  DEVICE  CACHE  FILE
       ACCESS  section for information on implementations that don’t surrender
       their setgid permission.)

       The local system administrator can disable the use of the  LSOFDEVCACHE
       environment  variable  or  change its name when building lsof.  Consult
       the output of -D?  for the environment variable’s name.

SYSTEM-WIDE DEVICE CACHE PATH

       The local system administrator may choose to have a system-wide  device
       cache file when building lsof.  That file will generally be constructed
       by a special system administration procedure when the system is  booted
       or  when  the contents of /dev or /devices) changes.  If defined, it is
       lsofs third device cache file path choice.

       You can tell that a system-wide device cache file is in effect for your
       local installation by examining the lsof help option output - i.e., the
       output from the -h or -?  option.

       Lsof will never write to the system-wide  device  cache  file  path  by
       default.   It  must  be  explicitly  named  with  a  -D  function  in a
       root-owned procedure.  Once the file has been  written,  the  procedure
       must  change  its permission modes to 0644 (owner-read and owner-write,
       group-read, and other-read).

PERSONAL DEVICE CACHE PATH (DEFAULT)

       The default device cache file path of  the  lsof  distribution  is  one
       recorded  in  the  home  directory  of the real UID that executes lsof.
       Added to the home directory is a second  path  component  of  the  form
       .lsof_hostname.

       This is lsofs fourth device cache file path choice, and is usually the
       default.  If a system-wide device cache file path was defined when lsof
       was  built, this fourth choice will be applied when lsof can’t find the
       system-wide device cache file.  This is the only  time  lsof  uses  two
       paths when reading the device cache file.

       The  hostname  part  of  the  second  component is the base name of the
       executing host, as  returned  by  gethostname(2).   The  base  name  is
       defined   to  be  the  characters  preceding  the  first  ‘.’   in  the
       gethostname(2) output, or all the gethostname(2) output if it  contains
       no ‘.’.

       The  device  cache  file  belongs  to  the  user ID and is readable and
       writable by the user ID  alone  -  i.e.,  its  modes  are  0600.   Each
       distinct real user ID on a given host that executes lsof has a distinct
       device cache file.  The hostname part of the path distinguishes  device
       cache  files  in  an NFS-mounted home directory into which device cache
       files are written from several different hosts.

       The personal device cache file path formed by this method represents  a
       device  cache  file that lsof will attempt to read, and will attempt to
       write should it not exist  or  should  its  contents  be  incorrect  or
       outdated.

       The -Dr option without a path name argument will inhibit the writing of
       a new device cache file.

       The -D?  option will list the format specification for constructing the
       personal  device  cache  file.   The  conversions  used  in  the format
       specification  are  described  in  the  00DCACHE  file  of   the   lsof
       distribution.

MODIFIED PERSONAL DEVICE CACHE PATH

       If  this  option is defined by the local system administrator when lsof
       is built, the LSOFPERSDCPATH environment variable contents may be  used
       to add a component of the personal device cache file path.

       The  LSOFPERSDCPATH  variable  contents are inserted in the path at the
       place  marked  by  the  local  system  administrator  with  the  ‘‘%p’’
       conversion  in  the  HASPERSDC  format  specification  of the dialect’s
       machine.h header file.  (It’s placed right after the home directory  in
       the default lsof distribution.)

       Thus,  for  example,  if  LSOFPERSDCPATH  contains  ‘‘LSOF’’,  the home
       directory is ‘‘/Homes/abe’’, the host name is ‘‘lsof.itap.purdue.edu’’,
       and  the  HASPERSDC  format  is  the  default  (‘‘%h/%p.lsof_%L’’), the
       modified personal device cache file path is:

            /Homes/abe/LSOF/.lsof_vic

       The LSOFPERSDCPATH  environment  variable  is  ignored  when  the  lsof
       process is setuid-root or when the real UID of the process is root.

       Lsof  will  not  write to a modified personal device cache file path if
       the lsof process doesn’t surrender setgid permission.   (See  the  LSOF
       PERMISSIONS  THAT AFFECT DEVICE CACHE FILE ACCESS section for a list of
       implementations that normally don’t surrender their setgid permission.)

       If,  for example, you want to create a sub-directory of personal device
       cache file paths by using the LSOFPERSDCPATH  environment  variable  to
       name  it,  and  lsof  doesn’t surrender its setgid permission, you will
       have to allow lsof  to  create  device  cache  files  at  the  standard
       personal path and move them to your subdirectory with shell commands.

       The  local  system  administrator may: disable this option when lsof is
       built; change the name of the environment variable from  LSOFPERSDCPATH
       to  something else; change the HASPERSDC format to include the personal
       path component in another place; or exclude the personal path component
       entirely.   Consult  the  output of the -D?  option for the environment
       variable’s name and the HASPERSDC format specification.

DIAGNOSTICS

       Errors are identified with messages on the standard error file.

       Lsof returns a one (1) if any error was detected, including the failure
       to locate command names, file names, Internet addresses or files, login
       names, NFS files, PIDs, PGIDs, or UIDs it was asked to list.  If the -V
       option  is  specified, lsof will indicate the search items it failed to
       list.

       It returns a zero (0) if no errors were detected and if it was able  to
       list some information about all the specified search arguments.

       When  lsof  cannot  open  access  to  /dev  (or /devices) or one of its
       subdirectories, or get information on a file in them with  stat(2),  it
       issues  a  warning message and continues.  That lsof will issue warning
       messages about inaccessible files in /dev (or /devices) is indicated in
       its  help  output - requested with the -h or >B -?  options -  with the
       message:

            Inaccessible /dev warnings are enabled.

       The warning message may be suppressed with the -w option.  It may  also
       have been suppressed by the system administrator when lsof was compiled
       by the setting of the WARNDEVACCESS  definition.   In  this  case,  the
       output from the help options will include the message:

            Inaccessible /dev warnings are disabled.

       Inaccessible  device  warning messages usually disappear after lsof has
       created a working device cache file.

EXAMPLES

       For a more extensive set of examples, documented more  fully,  see  the
       00QUICKSTART file of the lsof distribution.

       To list all open files, use:

              lsof

       To list all open Internet, x.25 (HP-UX), and UNIX domain files, use:

              lsof -i -U

       To  list all open IPv4 network files in use by the process whose PID is
       1234, use:

              lsof -i 4 -a -p 1234

       Presuming the UNIX dialect  supports  IPv6,  to  list  only  open  IPv6
       network files, use:

              lsof -i 6

       To  list all files using any protocol on ports 513, 514, or 515 of host
       wonderland.cc.purdue.edu, use:

              lsof -i @wonderland.cc.purdue.edu:513-515

       To list all files using any protocol on any port of  mace.cc.purdue.edu
       (cc.purdue.edu is the default domain), use:

              lsof -i @mace

       To  list  all  open  files  for login name ‘‘abe’’, or user ID 1234, or
       process 456, or process 123, or process 789, use:

              lsof -p 456,123,789 -u 1234,abe

       To list all open files on device /dev/hd4, use:

              lsof /dev/hd4

       To find the process that has /u/abe/foo open, use:

              lsof /u/abe/foo

       To send a SIGHUP to the processes that have /u/abe/bar open, use:

              kill -HUP ‘lsof -t /u/abe/bar‘

       To find any open file, including an open UNIX domain socket file,  with
       the name /dev/log, use:

              lsof /dev/log

       To  find  processes  with  open  files  on  the  NFS  file system named
       /nfs/mount/point whose server is inaccessible, and presuming your mount
       table supplies the device number for /nfs/mount/point, use:

              lsof -b /nfs/mount/point

       To do the preceding search with warning messages suppressed, use:

              lsof -bw /nfs/mount/point

       To ignore the device cache file, use:

              lsof -Di

       To  obtain  PID  and  command  name field output for each process, file
       descriptor, file device number, and file inode number for each file  of
       each process, use:

              lsof -FpcfDi

       To  list  the files at descriptors 1 and 3 of every process running the
       lsof command for login ID ‘‘abe’’ every 10 seconds, use:

              lsof -c lsof -a -d 1 -d 3 -u abe -r10

       To list the current working directory of processes  running  a  command
       that is exactly four characters long and has an ’o’ or ’O’ in character
       three, use this regular expression form of the -c c option:

              lsof -c /^..o.$/i -a -d cwd

       To find an IP version 4 socket file by its associated numeric  dot-form
       address, use:

              lsof -i@128.210.15.17

       To  find  an  IP  version 6 socket file (when the UNIX dialect supports
       IPv6) by its associated numeric colon-form address, use:

              lsof -i@[0:1:2:3:4:5:6:7]

       To find an IP version 6 socket file (when  the  UNIX  dialect  supports
       IPv6)  by  an  associated  numeric colon-form address that has a run of
       zeroes in it - e.g., the loop-back address - use:

              lsof -i@[::1]

       To obtain a repeat mode marker line that  contains  the  current  time,
       use:

              lsof -rm====%T====

       To add spaces to the previous marker line, use:

              lsof -r "m==== %T ===="

BUGS

       Since  lsof  reads  kernel  memory  in its search for open files, rapid
       changes in kernel memory may produce unpredictable results.

       When a file has  multiple  record  locks,  the  lock  status  character
       (following  the  file  descriptor)  is derived from a test of the first
       lock structure, not from any combination of the individual record locks
       that might be described by multiple lock structures.

       Lsof can’t search for files with restrictive access permissions by name
       unless it is installed with root set-UID permission.  Otherwise  it  is
       limited  to  searching for files to which its user or its set-GID group
       (if any) has access permission.

       The display of the destination address of a raw socket (e.g., for ping)
       depends  on  the  UNIX  operating  system.   Some  dialects  store  the
       destination address in the raw socket’s protocol control block, some do
       not.

       Lsof can’t always represent Solaris device numbers in the same way that
       ls(1) does.  For example, the major and minor device numbers  that  the
       lstat(2) and stat(2) functions report for the directory on which CD-ROM
       files are mounted (typically /cdrom) are not the same as the ones  that
       it  reports for the device on which CD-ROM files are mounted (typically
       /dev/sr0).  (Lsof reports the directory numbers.)

       The support for /proc file systems is available only for BSD and  Tru64
       UNIX  dialects,  Linux,  and  dialects  derived  from  SYSV  R4 - e.g.,
       FreeBSD, NetBSD, OpenBSD, Solaris, UnixWare.

       Some /proc file items - device number, inode number, and  file  size  -
       are  unavailable in some dialects.  Searching for files in a /proc file
       system may require that the full path name be specified.

       No text (txt) file descriptors are displayed for Linux processes.   All
       entries  for  files  other than the current working directory, the root
       directory, and numerical file descriptors are labeled mem  descriptors.

       Lsof  can’t  search  for  Tru64 UNIX named pipes by name, because their
       kernel implementation of lstat(2) returns an improper device number for
       a named pipe.

       Lsof  can’t  report  fully or correctly on HP-UX 9.01, 10.20, and 11.00
       locks because of insufficient access to kernel data or  errors  in  the
       kernel  data.   See  the lsof FAQ (The FAQ section gives its location.)
       for details.

       The AIX SMT file  type  is  a  fabrication.   It’s  made  up  for  file
       structures    whose    type    (15)    isn’t   defined   in   the   AIX
       /usr/include/sys/file.h header file.   One  way  to  create  such  file
       structures  is  to  run  X  clients  with  the  DISPLAY variable set to
       ‘‘:0.0’’.

       The +|-f[cfgGn] option is not supported under /proc-based  Linux  lsof,
       because it doesn’t read kernel structures from kernel memory.

ENVIRONMENT

       Lsof may access these environment variables.

       LANG              defines  a language locale.  See setlocale(3) for the
                         names of other variables that can be used in place of
                         LANG - e.g., LC_ALL, LC_TYPE, etc.

       LSOFDEVCACHE      defines  the  path  to  a device cache file.  See the
                         DEVICE  CACHE  PATH  FROM  AN  ENVIRONMENT   VARIABLE
                         section for more information.

       LSOFPERSDCPATH    defines  the  middle component of a modified personal
                         device cache file path.  See  the  MODIFIED  PERSONAL
                         DEVICE CACHE PATH section for more information.

FAQ

       Frequently-asked  questions and their answers (an FAQ) are available in
       the 00FAQ file of the lsof distribution.

       That file is also available via anonymous ftp from lsof.itap.purdue.edu
       at pub/tools/unix/lsofFAQ.  The URL is:

              ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/FAQ

FILES

       /dev/kmem         kernel virtual memory device

       /dev/mem          physical memory device

       /dev/swap         system paging device

       .lsof_hostname    lsofs  device  cache  file (The suffix, hostname, is
                         the first component of the host’s  name  returned  by
                         gethostname(2).)

AUTHORS

       Lsof  was  written  by  Victor  A.  Abell  <abe@purdue.edu>  of  Purdue
       University.  Many others have contributed to lsof.  They’re  listed  in
       the 00CREDITS file of the lsof distribution.

DISTRIBUTION

       The latest distribution of lsof is available via anonymous ftp from the
       host lsof.itap.purdue.edu.  You’ll find the lsof  distribution  in  the
       pub/tools/unix/lsof directory.

       You can also use this URL:

              ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof

       Lsof  is also mirrored elsewhere.  When you access lsof.itap.purdue.edu
       and change to its pub/tools/unix/lsof directory, you’ll be given a list
       of  some mirror sites.  The pub/tools/unix/lsof directory also contains
       a more complete list in its mirrors file.  Use mirrors with  caution  -
       not all mirrors always have the latest lsof revision.

       Some     pre-compiled     Lsof    executables    are    available    on
       lsof.itap.purdue.edu, but their use is discouraged - it’s  better  that
       you  build  your  own  from  the  sources.   If you feel you must use a
       pre-compiled executable, please read the cautions that  appear  in  the
       README  files of the pub/tools/unix/lsof/binaries subdirectories and in
       the 00* files of the distribution.

       More  information  on  the  lsof  distribution  can  be  found  in  its
       README.lsof_<version> file.  If you intend to get the lsof distribution
       and build it, please read README.lsof_<version> and the other 00* files
       of the distribution before sending questions to the author.

SEE ALSO

       Not  all  the following manual pages may exist in every UNIX dialect to
       which lsof has been ported.

       access(2), awk(1), crash(1), fattach(3C),  ff(1),  fstat(8),  fuser(1),
       gethostname(2),    isprint(3),    kill(1),    localtime(3),   lstat(2),
       modload(8),   mount(8),   netstat(1),   ofiles(8L),   perl(1),   ps(1),
       readlink(2), setlocale(3), stat(2), strftime(3), time(2), uname(1).

                                 Revision-4.81