lsof

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



NAME
       lsof - list open files

SYNOPSIS
       lsof [ -?abChlnNoOPstUvwX ] [ -A A ] [ -c c ] [ -d d ] [ -D D ] [ -F
       [f] ] [ -g [s] ] [ -i [i] ] [ -k k ] [ -m m ] [ -p s ] [ -r [t] ] [ -S
       [t] ] [ -u s ] [ -- ] [ names ]

DESCRIPTION
       Lsof revision 3.61 lists information about files opened by processes
       for the following Unix dialects:

            AIX 3.2.4, 3.2.5, 4.1, and 4.1.[1234] for the IBM
                 RISC/System 6000
            BSDI BSD/OS 2.0, 2.0.1, and 2.1-BETA for Intel-based
                 systems
            EP/IX 2.1.1 for the CDC 4680
            FreeBSD 1.1.5.1, 2.0, 2.0.5, and 2.1 for Intel-based
                 systems
            HP-UX 8.x, 9.x, and 10 for HP systems
            IRIX 4.0.5H, 5.2, 5.3, 6.0, 6.0.1, 6.1, and 6.2-BETA for
                 SGI systems
            Linux through 1.3.56 for Intel-based systems
            NetBSD 1.0 and 1.1 for Intel and SPARC-based systems
            NEXTSTEP 2.1 and 3.[0123], all architectures
            OSF/1 2.0, 3.[02], and 4.0 BETA for DEC Alpha
            PTX 2.1.[156], 4.0.[23], and 4.1.[02] for Sequent systems
            RISC/os 4.52 for MIPS R2000-based systems
            SCO OpenDesktop or OpenServer 1.1, 3.0, and 5.0 for
                 Intel-based systems
            Solaris 2.[12345]
            SunOS 4.1.[1234]
            Ultrix 2.2, 4.2, 4.3, 4.4, and 4.5 for DEC RISC and VAX

       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.

       Lsof may work on other Unix dialects - e.g., AIX 3.2.3, EP/IX 1.4.3,
       FreeBSD 1.0e, HP-UX 7.x, IRIX 5.1.1, NEXTSTEP 2.[01], and SunOS 4.1 -
       but has not been tested on any of them recently.

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

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

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

       Values are optional following several options: -F, -g, -r, and -S.
       When you have no values for these options, 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''.

       -? -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.  Section 4.3.1 of the 00FAQ file of the lsof
                distribution has 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.

       -C       This option disables the reporting of partial path name
                components from the kernel's name cache.  See the KERNEL NAME
                CACHE section for more information.

       -d d     This option selects the listing of files whose file
                descriptors are in the comma-separated set s - e.g., ``1,3''
                or ``6,cwd,2''.  (There should be no spaces in the set.)

                A file descriptor number range may be included 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''.

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

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

       -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 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 and the NL field terminator is used.

                When the field selection character list contains only a zero
                (`0'), all fields are selected 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 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 (PGRP) numbers are
                in the comma-separated set s - e.g., ``123'' or ``123,456''.
                (There should be no spaces in the set.)

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

                The -g option also enables the output display of PGRP numbers.
                When specified without a PGRP 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.

                Multiple addresses may be specified with multiple -i options.
                They are joined in a single ORed set before participating in
                AND option selection.

                An Internet address is specified in the form:

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

                where:
                     protocol is a protocol name - e.g., TCP.
                     hostname is an Internet host name.
                     hostaddr is an Internet host address in dot form.
                     service is an /etc/services name - e.g., smtp.
                     port is a port number.

                At least one address component - protocol, host specification,
                or port specification - 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 or port number.  If
                service is specified, protocol must also be specified.  Use
                any case - lower or upper - for protocol.

                Here are some sample addresses:
                     TCP:25 - TCP and port 25
                     @1.2.3.4 - Internet host address 1.2.3.4
                     UDP:who - UDP who service port
                     TCP@vic.cc:513 - TCP, port 513 and host name vic.cc

       -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.

       -m m     This option specifies a kernel memory file, c, in place of
                /dev/kmem or /dev/mem - e.g., a crash dump file.

       -n       This option inhibits the conversion of network numbers to host
                names for network files.  Inhibiting conversion may make lsof
                run a little 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.

                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       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 displays
                output on open files as selected by other options, delays t
                seconds (the default is fifteen), then repeats its output
                display, delaying and producing output repetitively until
                stopped with an interrupt or quit signal.  When no delay time,
                t, is specified, lsof uses a default of fifteen.

                Lsof marks the end of each set of output: 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.

       -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 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.

       -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       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.

       -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.

       -w       This option causes lsof to suppress all warning messages.  The
                -t option selects this 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.

                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 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 3.2.x and 4.1[.x]
                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 00FAQ and 00README files 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.

           PTX:
                This Sequent PTX -X option directs lsof to list file link
                count (``ct=<n>') and inode address (``ina=0x<a>'') at the end
                of the NAME column.  The file link count (decimal) indicates
                the number of concurrent users of the file.  The kernel inode
                address (hexadecimal) is a value that is sometimes useful when
                working with a malfunctioning system.  (Also see the manual
                page for the crash(1) application.)

                Link count data, when output as a field, has a field
                identifier character of `1'; inode address, `2'.

       --       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 mount point of a file system or the device of
                the mount point of a file system, lsof will list all the files
                open on the file system.  If a name is the base name of a
                family of multiplexed files - e. g, AIX's /dev/pts - lsof will
                list all the associated multipled files on the device that are
                open - e.g., /dev/pts/1, /dev/pts/2, etc.

                If a name is a Unix domain socket name, lsof will search for
                it by the characters of the name alone - both as specified and
                as resolved from symbolic links.  When the socket uses a name
                that is a symbolic link to another, you must specify the name
                the socket uses.  However, if the socket uses the symbolic
                link's resolution, you may specify it or the symbolic link
                origination.  When asking lsof to search for a Unix domain
                socket name, be careful to specify its absolute path, just as
                it appears in kernel structures.  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 structures
                associated with Unix domain sockets.

                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 3.2.5 (AFS 3.3a)
            AIX 4.1.4 (AFS 3.4a)
            HP-UX 9.0.5 (AFS 3.4a)
            Linux 1.2.13 (AFS 3.3)
            NEXTSTEP 3.2 (AFS 3.3)
            Solaris 2.4 (AFS 3.4a)
            Solaris 2.5 (AFS 3.4-Alpha)
            SunOS 4.1.4 (AFS 3.3a)
            Ultrix 4.2 RISC (AFS 3.2b)

       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 INODE 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 -?

       Section 4.3.1 of the 00FAQ file of the lsof distribution has 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 option.  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).  When HASSECURITY is not
       defined, anyone may list all open files.

       Help output, presented in response to the -h or -?  option, gives the
       HASSECURITY definition status.

       See the Security section of the 0README file of the lsof distribution
       for information on building lsof with the HASSECURITY option 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 and 00FAQ (section 4.2) files that accompany the
       lsof distribution.

       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.

       COMMAND    contains the first nine characters of the name of the Unix
                  command associated with the process.

       PID        is the Process IDentification number of the process.

       PGRP       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.  (See the -l option description.)

       FD         is the File Descriptor number of the file or:

                       cwd  current working directory;
                       Lnn  library references;
                       ltx  shared library text (code and data);
                       Mxx  hex memory-mapped type number xx.
                       m86  DOS Merge mapped file;
                       mem  memory-mapped file;
                       pd   parent directory;
                       rtd  root directory;
                       txt  program text (code and data);
                       v86  VP/ix mapped file;

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

                       r for read access;
                       w for write access;
                       u for read and write access;
                       space if unknown (e.g., cwd or txt).

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

                       L for a local lock of unknown type;
                       N for an 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;
                       space if there is no lock.

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

                  or ``dnet'' for a DECnet 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 ``DIR'' for a directory;

                  or ``DOOR'' for a VDOOR file;

                  or ``FIFO'' for a FIFO special file;

                  or ``LINK'' for a symbolic link file;

                  or ``MPB'' for a multiplexed block file;

                  or ``MPC'' for a multiplexed character file;

                  or ``PCTL'' for a /proc control file;

                  or ``PCUR'' for the current /proc process;

                  or ``PDIR'' for a /proc directory;

                  or ``PFIL'' for an executable /proc file;

                  or ``PFPR'' for a /proc FP register set;

                  or ``PGRP'' for a /proc group notifier file;

                  or ``PIPE'' for an Ultrix 4.2 pipe;

                  or ``PMEM'' for a /proc memory image file;

                  or ``PNTF'' for a /proc process notifier file;

                  or ``PORT'' for an Ultrix SYSV named pipe;

                  or ``PREG'' for a /proc register file;

                  or ``PSTA'' for a /proc status file;

                  or ``REG'' for a regular file.

       DEVICE     contains the major and minor device numbers for a character
                  special, block special, regular, directory or NFS file (an
                  HP-UX minor device number is listed in hexadecimal, as is a
                  DEC OSF/1 minor device number larger than 99,999);

                  or the protocol control block address of a DECnet (Ultrix
                  4.[23]), Internet, Unix, or x.25 (HP-UX) network file - the
                  address that appears in the -A output from some netstat(1)
                  programs;

                  or ``memory'' for a memory file system node under OSF/1 on
                  the DEC Alpha;

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

                  or a kernel reference address that identifies the file.  The
                  kernel reference address may be used for FIFO's, for
                  example.

                  Usually only the lower thirty two bits of OSF/1 DEC Alpha
                  kernel addresses are displayed.

       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.  The file size is
                  displayed in decimal; the offset is displayed in decimal
                  with a leading ``0t'' if it is less than 100,000,000; in
                  hexadecimal with a leading ``0x'' if it is larger than
                  99,999,999.  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.  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.

       INODE      is the inode number of a local file, truncated and prefixed
                  with an asterisk (`*') if it is too large for the output
                  field;

                  or the inode number of an NFS file in the server host,
                  truncated and prefixed with an asterisk (`*') if the number
                  is too large for the output field; ;

                  or the Internet protocol type - e. g, ``TCP'';

                  or ``STR'' for a stream;

                  or ``CCITT'' for an HP-UX x.25 socket.

       NAME       is the name of the mount point and file system on which the
                  file resides (Under IRIX 5.2 the appearance of ``(PIPE)''
                  identifies a pipe file.);

                  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
                  (as numbers or names, depending on the -H and -P options); a
                  UDP destination Internet address may be followed by the
                  amount of time that's elapsed since the last packet was sent
                  to the destination;

                  or the local and remote node and object addresses of a
                  DECnet file (The node address appears as an area.node number
                  pair if the -H option is specified.);

                  or the address or name of a Unix domain socket;

                  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 Unix stream device and
                  module names, separated by ``->'';

                  or the SunOS current working or root directory path name;

                  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:'' for an IRIX (versions below 5.2) common file
                  system entry;

                  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 OSF/1 DEC Alpha files -
                  typically terminal files that have been flagged with the
                  TIOCNOTTY ioctl and closed by daemons;

                  or ``r=count/bytes w=count/bytes'' for incomplete EP/IX
                  2.1.1 file structures (ones with no vnode or socket
                  pointer), with
                       r signifying read statistics,
                       count giving the operation count,
                       bytes giving bytes transferred,
                       w signifying write statistics;

                  or ``rd=<offset>'' and ``wr=<offset>'' for the values of the
                  read and write offsets of a FIFO.

       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.

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.

       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 (PGRP) 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.

       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).

       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
            d    file's device character code
            D    file's major/minor device number (0x<hexadecimal>)
            f    file descriptor
            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
            o    file's offset (0t<decimal> or 0x<hexadecimal>)
            p    process ID (always selected)
            g    process group ID
            P    protocol name
            s    file's size
            S    file's stream identification
            t    file's type
            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).

       Two 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.

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 an SGI IRIX 5.2 /etc/mtab for a file
       system remotely mounted via NFS:

            ... nfs rw,grpid,intr,nodevs,retry=6,dev=00100007 ...

       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, DEC OSF/1, FreeBSD,
       NetBSD, and Ultrix.  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 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 appear to
       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) 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.  Section 3.1.2 of the 00FAQ file of the lsof
       distribution has more information on this situation.

       Lsof can report path name components for these dialects:

            BSDI BSD/OS 2.0, 2.0.1, and 2.1-BETA
            EP/IX 2.1.1
            FreeBSD 1.1.5.1, 2.0, 2.0.5, and 2.1
            HP-UX 9.x and 10.x
            Linux through 1.3.56
            NetBSD 1.0 and 1.1
            NEXTSTEP 3.[0123]
            OSF/1 2.0, 3.0, 3.2, and 4.0 BETA
            PTX 2.1.[156], 4.0.[23], and 4.1.[02]
            SCO OpenDesktop or OpenServer 1.1 and 3.0
            SGI IRIX 5.3
            Solaris 2.[345]
            SunOS 4.1.[23]
            Ultrix 2.2 and 4.2

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

            AIX 3.2.4, 3.2.5, 4.1, and 4.1.[1234]
            SGI IRIX 4.0.5H, 5.2, 6.0, 6.0.1, 6.1, and 6.2-BETA

       Lsof may be able to report path name components for these dialects, but
       the code hasn't been tested on them:

            HP-UX 8.x
            NEXTSTEP 2.1
            OSF/1 1.3
            Solaris 2.[12]
            SunOS 4.1.[14]
            Ultrix 4.3, 4.4, and 4.5

       If you want to know why lsof can't report path name components for some
       dialects, consult section 3.1 of the 00FAQ file of the lsof
       distribution.

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 maintains an ASCII text file of cached /dev (or
       /devices) information.  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.

            none

       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 3.2.4, 3.2.5, 4.1, and 4.1.[1234] for the IBM
                 RISC/System 6000
            BSDI BSD/OS 2.0, 2.0.1, and 2.1-BETA for Intel-based
                 systems
            EP/IX 2.1.1 for the CDC 4680
            FreeBSD 1.1.5.1, 2.0, 2.0.5, and 2.1 for Intel-based
                 systems
            HP-UX 8.x, 9.x, and 10 for HP systems
            IRIX 4.0.5H, 5.2, 5.3, 6.0, 6.0.1, and 6.1 for SGI systems
            Linux through 1.3.56 for Intel-based systems
            NetBSD 1.0 and 1.1 for Intel and SPARC-based systems
            NEXTSTEP 2.1 and 3.[0123], all architectures
            OSF/1 2.0, 3.[02], and 4.0 BETA for DEC Alpha
            PTX 2.1.[156], 4.0.[23], and 4.1.[02] for Sequent systems
            RISC/os 4.52 for MIPS R2000-based systems
            SCO OpenDesktop or OpenServer 1.1, 3.0, and 5.0 for
                 Intel-based systems
            Solaris 2.[12345]
            SunOS 4.1.[1234]
            Ultrix 2.2, 4.2, 4.3, 4.4, and 4.5 for DEC RISC and VAX

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

       When lsof cannot open access to /dev (or /devices) or one of its
       subdirectories, it issues a warning message and continues.  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 the latter case, the
       output from lsof's -h or -?  option will contain the message:

            Warnings are disabled for inaccessible device directories.

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 files using any protocol on port 513 of host
       wonderland.cc.purdue.edu, use:

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

       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

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.

       Lsof startup time is long on dialects where scanning the /dev (or
       /devices) directory and the mount table are slow operations.  Where
       possible - e.g., when the listing of only network files is requested -
       the scans are avoided or deferred.  When the device cache file is in
       use, scanning /dev (or /devices) is avoided once the cache file has
       been written.

       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 and SunOS 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 system to which the Ultrix 2.2 port was directed is a local one
       that has been extensively updated with network features from the 4.3BSD
       Tahoe and Reno releases, so it may not match a standard Ultrix 2.2
       system, if there is any such system still in use.

       The support for.  /proc file systems is available only for BSD and OSF
       dialects, Linux, and dialects derived from SYSV R4 - e.g., FreeBSD,
       IRIX 5.[23], NetBSD, Solaris.  One SYSV R4 exception is EP/IX 2.1.1,
       where I have been unable to overcome conflicts between its svr3 and
       svr4 environments to build an lsof with /proc file system support.

       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.

       Door file system support under Solaris 2.5 is minimal, since the file
       system type is new and experimental.  Sun advises that the door file
       system and its interface are subject to change in future releases.

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.

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@cc.purdue.edu> of the Purdue
       University Computing Center (PUCC).  Many others have contributed to
       lsof.  They're listed in the 00CREDITS file of the lsof distribution.

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



                                 Revision-3.61                         LSOF(8)