Content-type: text/html Manpage of LSOF

LSOF

Section: Maintenance Commands (8)
Updated: Revision-3.62
Index Return to Main Contents
 

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 3.62 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


 

Index

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
AFS
SECURITY
OUTPUT
OUTPUT FOR OTHER PROGRAMS
BLOCKS AND TIMEOUTS
AVOIDING KERNEL BLOCKS
ALTERNATE DEVICE NUMBERS
KERNEL NAME CACHE
DEVICE CACHE FILE
LSOF PERMISSIONS THAT AFFECT DEVICE CACHE FILE ACCESS
DEVICE CACHE FILE PATH FROM THE -D OPTION
DEVICE CACHE PATH FROM AN ENVIRONMENT VARIABLE
SYSTEM-WIDE DEVICE CACHE PATH
PERSONAL DEVICE CACHE PATH (DEFAULT)
MODIFIED PERSONAL DEVICE CACHE PATH
DIAGNOSTICS
EXAMPLES
BUGS
ENVIRONMENT
FILES
AUTHORS
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 23:41:14 GMT, September 27, 2019