lsof

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



NAME
       lsof - list open files

SYNOPSIS
       lsof [ -?abChlnNOPRstUvVX ] [ -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] ] [ -S [t]
       ] [ -T [t] ] [ -u s ] [ +|-w ] [ -- ] [names]

DESCRIPTION
       Lsof revision 4.67 lists information about files opened by processes
       for the following UNIX dialects:

            AIX 4.3.[23], 5L, and 5.[12]
            Apple Darwin 1.[2-5], 5.x and 6.x for Power Macintosh systems
            BSDI BSD/OS 4.[13] for x86-based systems
            DEC OSF/1, Digital UNIX, Tru64 UNIX 4.0, and 5.[01]
            FreeBSD 4.[2345678] and 5.0 for x86-based systems
            FreeBSD 5.0 for Alpha and Sparc64 based systems
            HP-UX 11.00 and 11.11
            Linux 2.1.72 and above for x86-based systems
            NetBSD 1.[456] for Alpha, x86, and SPARC-based systems
            NEXTSTEP 3.[13] for NEXTSTEP architectures
            OpenBSD 2.[89] and 3.[012] for x86-based systems
            OPENSTEP 4.x
            Caldera OpenUNIX 8
            SCO OpenServer Release 5.0.[46] for x86-based systems
            SCO|Caldera UnixWare 7.1.[13] for x86-based systems
            Solaris 2.6, 7, 8, and 9

       (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] 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''.  One exception is the `^' (negated) login name
       or user ID (UID) specified with the -u option.  Since it is an
       exclusion, it is applied without ORing or ANDing and takes 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 - 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, and -T,
       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 and ends with a slash ('/'), the characters
                between the slashes is 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 of the UNIX command associated with a process to
                be printed in the COMMAND column.  (The default is nine.)

                If w is zero ('0'), all command characters 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, nor does it follow symbolic links within it.  The
                +D D option may be used to request a full-descent directory
                tree search, rooted at directory D.

                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
                descritors 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.  Symbolic links within directory D are
                ignored - i.e, not followed.

                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 lsof's use of the device cache file.  The
                use of this option is sometimes restricted.  See the DEVICE
                CACHE FILE section and the sections that follow it for more
                information on this option.

                -D must be followed by a function letter; the function letter
                may optionally be followed by a path name.  Lsof recognizes
                these function letters:

                     ? - report device cache file paths
                     b - build the device cache file
                     i - ignore the device cache file
                     r - read the device cache file
                     u - read and update the device cache file

                The b, r, and u functions, accompanied by a path name, are
                sometimes restricted.  When these functions are restricted,
                they will not appear in the description of the -D option that
                accompanies -h or -?  option output.  See the DEVICE CACHE
                FILE section and the sections that follow it for more
                information on these functions and when they're restricted.

                The ?  function reports the read-only and write paths that
                lsof can use for the device cache file, the names of any
                environment variables whose values lsof will examine when
                forming the device cache file path, and the format for the
                personal device cache file path.  (Escape the `?' character as
                your shell requires.)

                When available, the b, r, and u functions may be followed by
                the device cache file's path.  The standard default is
                .lsof_hostname in the home directory of the real user ID that
                executes lsof, but this could have been changed when lsof was
                configured and compiled.  (The output of the -h and -?
                options show the current default prefix - e.g., ``.lsof''.)
                The suffix, hostname, is the first component of the host's
                name returned by gethostname(2).

                When available, the b function directs lsof to build a new
                device cache file at the default or specified path.

                The i function directs lsof to ignore the default device cache
                file and obtain its information about devices via direct calls
                to the kernel.

                The r function directs lsof to read the device cache at the
                default or specified path, but prevents it from creating a new
                device cache file when none exists or the existing one is
                improperly structured.  The r function, when specified without
                a path name, prevents lsof from updating an incorrect or
                outdated device cache file, or creating a new one in its
                place.  The r function is always available when it is
                specified without a path name argument; it may be restricted
                by the permissions of the lsof process.

                When available, the u function directs lsof to read the device
                cache file at the default or specified path, if possible, and
                to rebuild it, if necessary.  This is the default device cache
                file function when no -D option has been specified.

       +|-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, 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 is properly terminated and isn'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 as in this example.

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

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

                     c    file structure use count
                     f    file structure address
                     g    file flag abbreviations
                     G    file flags in hexadecimal
                     n    file structure node address

                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 fields
                are selected (except the raw device 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 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.)

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

                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 lsof's -h or -?  output.)  Sequentially
                specifying -i4, followed by -i6 is the same as specifying -i,
                and vice-versa.  Specifying -i4, or -i6 after -i is the same
                as specifying -i4 or -i6 by itself.

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

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

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

                where:
                     46 specifies the IP version, IPv4 or IPv6
                          that applies to the following address.
                          '6' may be be specified only if the UNIX
                          dialect supports IPv6.  If neither '4' nor
                          '6' is specified, the following address
                          applies to all IP versions.
                     protocol is a protocol name - TCP or 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 and UDP 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 staring 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@vic.cc:513 - TCP, port 513 and host name vic.cc
                     tcp@foo:1-10,smtp,99 - TCP, ports 1 through 10,
                          service name smtp, port 99, host name foo
                     tcp@bar:smtp-nameserver - TCP, ports smtp through
                          nameserver, host bar
                     :time - either TCP or UDP 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 a kernel memory file, c, in place of
                /dev/kmem or /dev/mem - e.g., a crash dump file.

       +|-M     Enables (+) or disables (-) the reporting of portmapper
                registrations for local TCP and UDP 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 lsof's -h or -?
                option will report the default mode.  Disabling portmapper
                registration when it is already disabled or enabling it when
                already enabled is acceptable.  in a warning.

                When portmapper registration reporting is enabled, lsof
                displays the portmapper registration (if any) for local TCP or
                UDP 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 or UDP 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 selects the listing of files for the processes
                whose ID numbers are in the comma-separated set s - e.g.,
                ``123'' or ``123,456''.  (There should be no spaces in the
                set.)

                Multiple process ID numbers are joined in a single ORed set
                before participating in AND option selection.

       -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 host name
                lookup is not working properly.

       +|-r [t] 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 marker is
                `m'; otherwise the marker is ``========''.  The marker is
                followed by a NL character.

                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       This option directs lsof to display file size at all times.
                It causes the SIZE/OFF output column title to be changed to
                SIZE.  If the file does not have a size, nothing is displayed.

                The -o (without a following decimal digit count) 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 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 state 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>
                     WR=<window read length>  (not all dialects)
                     WW=<window write length> (not all dialects)

                When the field output mode is in effect (See OUTPUT FOR OTHER
                PROGRAMS.)  each item appears as a field with a `T' leading
                character, and the TCP or TPI state name has the prefix
                ``ST=''.

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

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

                     q    selects queue length reporting.
                     s    selects state reporting.
                     w    selects window size reporting (not
                          all dialects).

                State is reported by default.  The -h or -?  help output for
                the -T option will show whether window size reporting can be
                requested.

                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.

       -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 situtation 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       This is a dialect-specific option.

           AIX:
                WARNING: use of this option 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 it, but I think the possibility exists.

                This IBM AIX RISC/System 6000 -X option directs lsof to use
                the kernel readx() function.  (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.

                When readx() is enabled, lsof will attempt to report
                information on the text file being executed by each process
                and the shared libraries it uses.

                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 erroneously to believe 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.

       --       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
                multipled 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 search for
                it by the characters of the name alone - exactly as it is
                specified and is recorded in the kernel socket structure.
                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 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 0README file of the lsof distribution
       for information on building lsof with the HASSECURITY and
       HASNOSOCKSECURITY options enabled.

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

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

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

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

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

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

       Lsof only outputs printable (declared so by isprint(3)) ASCII
       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.

       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.

                  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.

       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);
                       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 ``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 ``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.

       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
                       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
                       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
                       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
                       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
                       RAIO      Reliant UNIX RAIO request
                       RC        file and record locking cache
                       REV       revoked
                       RSH       shared read
                       RSYN      read synchronization
                       SL        shared lock
                       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))
                       MP        memory-mapped
                       LCK       lock was applied
                       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 DEC OSF/1,
                  Digital UNIX, or 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 DEC OSF/1, Digital
                  UNIX, or 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.

       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 and UDP 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 ``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 DEC OSF/1, Digital UNIX, or
                  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, 7, 8, or 9 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.

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
            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):
                     ST=<state>
                     QR=<read queue size>
                     QS=<write queue size>
                     WR=<window read size>  (not all dialects)
                     WW=<window write size>  (not all dialects)
                 (TPI state information and window sizes aren't
                   reported for all supported UNIX dialects. The
                   -h or -? help output for the -T option will
                   show whether window size reporting can be
                   requested.)
            u    process user ID
            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.

       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, DEC
       OSF/1, Digital UNIX, 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 Digital
       UNIX or 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.)

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

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

       Lsof's use of the kernel name cache to identify the paths of files can
       lead it to report incorrect components under some circumstances.  This
       can happen when the kernel name cache uses device and node number as a
       key (e.g., Linux and 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:

            BSDI BSD/OS
            DC/OSx
            DEC OSF/1, Digital UNIX, Tru64 UNIX
            FreeBSD
            HP-UX
            Linux
            NetBSD
            NEXTSTEP
            OpenBSD
            Reliant UNIX
            Caldera OpenUNIX
            SCO OpenServer
            SCO|Caldera UnixWare
            Solaris

       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.

            DC/OSx 1.1 for Pyramid systems
            Reliant UNIX 5.4[34] for Pyramid systems

       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 4.3.[23], 5L, and 5.[12]
            Apple Darwin 1.[2-5], 5.x and 6.x for Power Macintosh systems
            BSDI BSD/OS 4.[13] for x86-based systems
            DEC OSF/1, Digital UNIX, Tru64 UNIX 4.0, and 5.[01]
            FreeBSD 4.[2345678] and 5.0 for x86-based systems
            FreeBSD 5.0 for Alpha and Sparc64 based systems
            HP-UX 11.00
            NetBSD 1.[456] for Alpha, x86, and SPARC-based systems
            NEXTSTEP 3.[13] for NEXTSTEP architectures
            OpenBSD 2.[89] and 3.[012] for x86-based systems
            OpenStep 4.x
            Caldera OpenUNIX 8
            SCO OpenServer Release 5.0.[46] for x86-based systems
            SCO|Caldera UnixWare 7.1.[13] for x86-based systems
            Solaris 2.6, 7, 8, and 9

       (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 2.1.72 and above (/proc-based lsof)

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

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

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

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

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

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

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

DEVICE CACHE PATH FROM AN ENVIRONMENT VARIABLE
       Lsof's second choice for the device cache file is the contents of the
       LSOFDEVCACHE environment variable.  It avoids this choice if the lsof
       process is setuid-root, or the real UID of the process is root.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       Thus, for example, if LSOFPERSDCPATH contains ``LSOF'', the home
       directory is ``/Homes/abe'', the host name is ``vic.cc.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]

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, DEC
       OSF/1, Digital UNIX, 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 DEC OSF/1, Digital UNIX, and 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.

       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 vic.cc.purdue.edu at
       pub/tools/unix/lsofFAQ.  The URL is:

              ftp://vic.cc.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    lsof's device cache file (The suffix, hostname, is
                         the first component of the host's name returned by
                         gethostname(2).)

AUTHORS
       Lsof was written by Victor A. Abell <abe@purdue.edu> of Purdue
       University.  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 vic.cc.purdue.edu.  You'll find the lsof distribution in the
       pub/tools/unix/lsof directory.

       You can also use this URL:

              ftp://vic.cc.purdue.edu/pub/tools/unix/lsof

       Lsof is also mirrored elsewhere.  When you access vic.cc.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 vic.cc.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
       Lsof versions 2 and 3 have been tested under older UNIX dialects.  They
       are available via anonymous ftp from vic.cc.purdue.edu in the
       pub/tools/unix/lsof/OLD directory.

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



                                 Revision-4.67                         LSOF(8)