
		Frequently Asked Questions about lsof

**********************************************************************
| The latest release of lsof is always available via anonymous ftp   |
| from vic.cc.purdue.edu.  Look in pub/lsof.README for its location. |
**********************************************************************

______________________________________________________________________

This file contains frequently asked questions about lsof and answers
to them.

Vic Abell <abe@purdue.edu>
November 28, 1999
______________________________________________________________________

Table of Contents:

1.0	General Concepts
1.1	Lsof -- what is it?
1.2	Where do I get lsof?
1.2.1	Are there mirror sites?
1.2.2	Are lsof executables available?
1.3	Is lsof year 2000 (Y2K) compliant?

2.0	Lsof Ports
2.1	What ports exist?
2.2	What about a new port?
2.2.1	User-contributed Ports
2.3	Why isn't there an AT&T SVR4 port?
2.4	Why isn't there an SGI IRIX port?

3.0	Lsof Problems
3.1	Why doesn't lsof report full path names?
3.1.1	Why do lsof -r reports show different path names?
3.1.2	Why does lsof report the wrong path names?
3.1.3	Why doesn't lsof report path names for unlinked (rm'd) files?
3.2	Why is lsof so slow?
3.3	Why doesn't lsof's setgid or setuid permission work?
3.4	Does lsof have security problems?
3.5	Will lsof show remote hosts using files via NFS?
3.6	Why doesn't lsof report locks held on NFS files?
3.6.1	Why does lsof report a one byte lock on byte zero as a full
	file lock?
3.7	Why does lsof report different values for open files on the
	same file system (the automounter phenomenon)?
3.8	Why don't lsof and netstat output match?
3.8.1	Why can't lsof find accesses to some TCP and UDP ports?
3.9	Why does lsof update the device cache file?
3.10	Why doesn't lsof report state for UDP socket files?
3.11	I am editing a file with vi; why doesn't lsof find the file?
3.12	Why doesn't lsof report TCP/TPI window and queue sizes for my
	dialect?
3.13	What does "no more information" in the NAME column mean?
3.14	Why doesn't lsof find a process that ps finds?
3.15	Why doesn't -V report a search failure?
3.16	Portmap problems
3.16.1	Why isn't a name displayed for the portmapper registration?
3.16.2	How can I display only portmap registrations?
3.16.3	Why doesn't lsof report portmap registrations for some ports?
3.17	Why is `lsof | wc` bigger than my system's open file limit?
3.18	Why doesn't lsof report file offset (position)?
3.19	Problems with path name arguments
3.19.1	How do I ask lsof to search a file system?
3.19.2	Why doesn't lsof find all the open files in a file system?
3.19.3	Why does the lsof exit code report it didn't find open files
	when some files were listed?
3.19.4	Why won't lsof find all the open files in a directory?
3.19.5	Why are the +D and +d options so slow?
3.19.6	Why do the +D and +d options produce warning messages?
3.20	Why can't my C compiler find the rpcent structure definition?
3.21	Why doesn't lsof report fully on file "foo" on UNIX dialect
	"bar?"
3.22	Problems loading and executing lsof
3.22.1	Why do I get a complaint when I execute lsof that some library
	file can't be found?
3.22.2	Why does lsof complain it can't open files?
3.22.3	Why does lsof warn "compiled for x ... y; this is z."?
3.22.4	How can I disable the kernel identity check?
3.23	Why don't ps(1) and lsof agree on the owner of a process?
3.24	Why doesn't lsof find an open socket file whose connection
	state is past CLOSE_WAIT?
3.25	Why don't machine.h definitions work when the surrounding
	comments are removed?

4.0	AIX Problems
4.1	What is the Stale Segment ID bug and why is -X needed?
4.1.1	Stale Segment ID APAR
4.2	Gcc Work-around for AIX 4.1x
4.3	Gcc and AIX 4.2
4.4	Why won't lsof's Configure allow the use of gcc for AIX
	below 4.1?
4.5	What is an AIX SMT file type?
4.6	Why does AIX lsof start so slowly?
4.7	Why does exec complain it can't find libc.a[shr.o]?

5.0	BSD/OS BSDI Problems
5.1	Why doesn't lsof report on open kernfs files?

6.0	DEC OSF/1, Digital UNIX, and Tru64 UNIX Problems
6.1	Why does lsof complain about non-existent /dev/fd entries?
6.2	Why does the Digital UNIX V3.2 ld complain about Ots* symbols?
6.3	Why can't lsof locate named pipes (FIFOs) under V3.2?
6.4	Why does lsof use the wrong configuration header files?
	For example, why can't the lsof compilation find cpus.h?

7.0	FreeBSD Problems
7.1	Why doesn't lsof report on open kernfs files?
7.2	Why doesn't lsof work under FreeBSD 4.0?

8.0	HP-UX Problems
8.1	Why doesn't an HP-UX lsof compilation use -O?
8.2	Where is x25L3.h under HP-UX 9.x?
8.3	Why doesn't lsof report all HP-UX 9.x locks?
8.4	Why doesn't lsof report HP-UX 10.20 locks correctly?
8.5	Why doesn't the CCITT support work under 10.x?
8.6	Why can't lsof be compiled with `cc -Aa` or `gcc -ansi` under
	HP-UX 10.x?
8.7	Why does lsof complain about no C compiler?
8.8	Why does Configure complain about q4 for HP-UX 11?

9.0	Linux Problems
9.1	What do /dev/kmem-based and /proc-based lsof mean?
9.2	/dev/kmem-based Linux lsof Questions
9.2.1	Why doesn't /dev/kmem-based lsof work (or even compile) on my
	Linux system?
9.2.1.1	Why does /dev/kmem-based Configure complain about
	/usr/src/linux?
9.2.2	Why does /dev/kmem-based lsof complain about /dev/kmem?
9.2.3	Why can't /dev/kmem-based lsof find kernel addresses?
9.2.4	Why does /dev/kmem-based lsof have trouble reading kernel
	structures?
9.2.5	Where is the system map file for kernel symbol->address
	translations for /dev/kmem-based lsof?  Why doesn't it match
	my kernel?
9.2.5.1	What do kernel symbol address mismatch error messages mean
	for /dev/kmem-based lsof?
9.2.5.2	Why does /dev/kmem-based lsof complain that query_module is
	unimplemented?
9.2.6	Why does /dev/kmem-based lsof complain about the random_fops
	and urandom_fops kernel symbols?
9.2.7	Why does /dev/kmem-based lsof complain about get_kernel_syms()?
9.2.8	Why does /dev/kmem-based lsof complain "WARNING: uncertain
	kernel loader format; assuming..."?
9.2.9	/dev/kmem-based lsof Problems Under Linux 2.1.x
9.2.9.1	Why does Configure say ``Testing lseek() with gcc'' for
	/dev/kmem-based lsof for Linux 2.1.x?
9.2.9.2	Why does Configure's lseek() test complain about read
	permissions for /dev/kmem-based lsof for Linux 2.1.x?
9.2.10	What do the /dev/kmem-based lsof WARNING messages about
	kncache.h mean?
9.2.11	What does "WARNING: kncache.h defines no kernel name caches."
	from /dev/kmem-based lsof mean?
9.3	/proc-based Linux lsof Questions
9.3.1	Why doesn't /proc-based lsof report file offsets (positions)?
9.3.2	Why does /proc-based lsof report "can't identify protocol" for
	some socket files?
9.3.3	Why does /proc-based lsof warn about unsupported formats?
9.3.4   Why does /proc-based lsof report "(deleted)" after a path name?
9.3.5	Why doesn't /proc-based lsof report full open file information
	for all processes?
9.3.6	Why won't Customize offer to change HASDCACHE or WARNDEVACCESS
	for /proc-based lsof?
9.4	What about lsof, Linux, and the Alpha or SPARC processors?

10.0	NetBSD Problems
10.1	Why doesn't lsof report on open kernfs files?

11.0	NEXTSTEP and OpenStep Problems
11.1	Why can't lsof report on 3.1 lockf() or fcntl(F_SETLK)
	locks?
11.2	Why doesn't lsof compile for NEXTSTEP with AFS?

12.0	OpenBSD Problems
12.1	Why doesn't lsof support kernfs on my OpenBSD system?
12.2	Will lsof work on OpenBSD on non-Intel-based architectures?
12.3	<sys/pipe.h> problems
12.3.1	Why does the compiler claim nbpg isn't defined?
12.3.2	What value should I assign to nbpg?

13.0	Output problems
13.1	Why do the lsof column sizes change?
13.2	Why does the offset have ``0t' and ``0x'' prefixes?
13.3	What are the values printed in the FILE_FLAG column
	and why is 0x<value> sometimes included?
13.3.1	Why doesn't lsof display FILE_FLAG values for my dialect?
13.4	Network Addresses
13.4.1	Why does lsof's -n option cause IPv4 addresses, mapped to
	IPv6, to be displayed in IPv6 notation?

14.0	Pyramid Version Problems
14.1	DC/OSx Problems
14.2	Reliant UNIX Problems
14.2.1	Why does lsof complain that it can't find /stand/unix?
14.2.2	Why does lsof complain about bad kernel addresses?
14.2.3	Why does the Reliant C compiler give so many warning messages
	when compiling lsof?
14.2.4	Why does the lsof compilation require -Klp64 for Reliant UNIX
	5.44 and why does my compiler reject it?

15.0	SCO Problems
15.1	SCO OpenServer Problems
15.1.1	How can I avoid segmentation faults when compiling lsof?
15.1.2	Where is libsocket.a?
15.1.3	Why do I get "warning C4200" messages when I compile lsof?
15.2	SCO UnixWare Problems

16.0	Sun Problems
16.1	My Sun gcc-compiled lsof doesn't work -- why?
16.2	How can I make lsof compile with gcc under Solaris 2.[456],
	2.5.1, or 7?
16.3	How can I make lsof compile with gcc under SunOS 4.1.x?
16.4	Why does Solaris Sun C complain about system header files?
16.5	Why doesn't lsof work under my Solaris 2.4 system?
16.6	Where are the Solaris header files?
16.7	Where is the Solaris /usr/src/uts/<architecture>/sys/machparam.h?
16.8	Why does Solaris lsof say ``can't read proc table''?
16.9	Why does Solaris lsof complain about a bad cached clone device?
16.10	Why doesn't Solaris make generate .o files?
16.11	Why does lsof report some Solaris 2.3 and 2.4 lock types as `N'?
16.12	Why does lsof Configure say "WARNING: no cc in ..."?
16.13	Solaris 7 and 8 Problems
16.13.1 Why does lsof say the compiler isn't adequate for Solaris
	7 or 8?
16.13.2	Why does Solaris 7 or 8 lsof say "FATAL: lsof was compiled
	for..."?
16.13.3	How do I build lsof for a 64 bit Solaris kernel under a 32
	bit Solaris kernel?
16.13.4	How do I install lsof for Solaris 7 or 8?
16.13.5	Why does my Solaris 7 or 8 system say it cannot execute lsof?
16.13.6	How do I build a gcc that will produce 64 bit Solaris 7 and
	8 executables?
16.14	Solaris and COMMON
16.14.1	What does COMMON mean in the NAME column for a Solaris VCHR
	file?
16.14.2	Why does a COMMON Solaris VCHR file sometimes seem to have an
	incorrect minor device number?
16.15	Why don't lsof and Solaris pfiles reports always match?
16.16	Why doesn't lsof report node number and name for some
	SunOS 4.1.4 Auspex processes?

17.0	Lsof Features
17.1	Why doesn't lsof doesn't report on /proc entries on my
	system?
17.2	How do I disable the device cache file feature or alter
	it's behavior?
17.2.1	What's the risk with a perverted device cache file?
17.2.2	How do I put the full host name in a personal device cache file
	path?
17.2.3	How do I put the personal device cache file in /tmp?
17.3	Why doesn't lsof know about AFS files on my favorite dialect?
17.3.1	Why doesn't lsof report node numbers for all AFS volume files,
	or how do I reveal dynamic module addresses to lsof?
______________________________________________________________________


1.0	General Concepts

1.1	Lsof -- what is it?

	Lsof is a UNIX-specific tool.  Its name stands for LiSt
	Open Files, and it does just that.  It lists information
	about files that are open by the processes running on a
	UNIX system.

	See the lsof man page, the 00DIST file, the 00QUICKSTART
	file, and the 00README file of the lsof distribution for
	more information.

1.2	Where do I get lsof?

	Lsof is available via anonymous ftp from vic.cc.purdue.edu.
	Look in the pub/tools/unix/lsof sub-directory.

	Compressed and gzip'd tar files with PGP certificates are
	available.

1.2.1	Are there mirror sites?

	The lsof distribution is currently mirrored at:

	ftp://coast.cs.purdue.edu/pub/tools/unix/lsof
	ftp://ftp.auscert.org.au/pub/mirrors/vic.cc.purdue.edu/lsof
	ftp://ftp.cert.dfn.de/pub/tools/admin/lsof
	ftp://ftp.crc.doc.ca/packages/lsof
	ftp://ftp.cs.columbia.edu/archives/lsof
	ftp://ftp.fu-berlin.de/pub/unix/tools/lsof
	ftp://ftp.gre.ac.uk/pub/tools/lsof
	ftp://ftp.rge.com/pub/lsof
	ftp://ftp.sunet.se/pub/unix/admin/lsof
	ftp://ftp.tau.ac.il/pub/unix/admin
	ftp://ftp.tu-darmstadt.de/pub/sysadmin/lsof
	ftp://ftp.tux.org/pub/sites/vic.cc.purdue.edu/tools/unix/lsof
	ftp://ftp.unicamp.br/pub/unix-tools/lsof
	ftp://ftp.uni-mainz.de/pub/misc/lsof
	ftp://ftp.web.ad.jp/pub/UNIX/tools/lsof
	ftp://gd.tuwien.ac.at/utils/admin-tools/lsof
	ftp://raver.net/pub/lsof
	ftp://sunsite.icm.edu.pl/pub/unix/net/lsof
	ftp://sunsite.ualberta.ca/pub/Mirror/lsof
	ftp://wuarchive.wustl.edu/packages/security/lsof

1.2.2	Are lsof executables available?

	Some lsof executables are available in the subdirectory
	tree pub/tools/unix/lsof/binaries  These are neither guaranteed
	to be current nor cover every dialect and machine architecture.

	I don't recommend you use pre-compiled lsof binaries; I
	recommend you obtain the sources and build your own binary.
	Even if you're a Sun user without a Sun C compiler, you
	can use gcc to compile lsof.

	If you must use a binary file, please be conscious of the
	security and configuration implications in using an executable
	of unknown or different origin.  The lsof binaries are
	accompanied by PGP certificates.  Please use them!

	Three additional cautions apply to executables:

	1.  Don't try to use an lsof executable, compiled for one
	    version of a UNIX dialect, on another.

	2.  A SunOS lsof executable, compiled for one Sun architecture,
	    won't work on different Sun architecture, even if both
	    systems run the same version of SunOS.

	3.  A Solaris lsof executable, compiled for one Sun
	    architecture, isn't guaranteed to work on a different
	    Sun architecture, even if both systems run the same
	    version of Solaris.

1.3	Is lsof year 2000 (Y2K) compliant?

	Probably.

	Lsof doesn't do any time or day computations with anything
	other than UNIX time_t values -- e.g., checking the time
	stamps of files.  It doesn't use ctime(3) or localtime(3).

	However, I haven't done any lsof Y2K compliance testing.
	Since I distribute the lsof sources freely and find it
	difficult enough to keep lsof running on 40+ UNIX dialects
	in the face of constant new dialect releases, I expect lsof
	beneficiaries to share the work.  Y2K compliance testing
	is a share.

	These people have done lsof Y2K testing and report that
	it passed their tests:

	    Sylvain Robitaille <syl@alcor.concordia.ca>


2.0	Lsof Ports

2.1	What ports exist?

	The pub/lsof.README file carries the latest port information:

	    AIX 4.1.[45], 4.2[.1], and 4.3[.123]
	    BSDI BSD/OS 2.1, 3.[01], and 4.[01] for Intel-based systems
	    DC/OSx 1.1 for Pyramid systems
	    DEC OSF/1, Digital UNIX, Tru64 UNIX 2.0, 3.2, 4.0, and 5.0
	    FreeBSD 2.1.6, 2.2[.x], 3.[012], and 4.0 for Intel-based
		systems
	    HP-UX 9.01, 10.20, and 11.00
	    Linux 2.0.3[2346], 2.1.x, and 2.2.x for Intel-based systems
	    NetBSD 1.[234] for Intel and SPARC-based systems
	    NEXTSTEP 3.[13]
	    OpenBSD 2.[0123456] for Intel-based systems
	    Reliant UNIX 5.4[34] for Pyramid systems
	    SCO OpenServer Release 3.0 and 5.0.[0245] for Intel-based
		systems
	    SCO UnixWare 2.1.[123] and 7[[.0].1] for Intel-based systems
	    Sequent PTX 2.1.9, 4.2.[13], 4.[34], and 4.4.[124]
	    Solaris 2.5.1, 2.6, 7, 8 BETA, and 8 BETA-Refresh
	    SunOS 4.1.x
	    Ultrix 4.2

	Lsof version 4 predecessors, versions 3 and 4, may support
	older version of some dialects.  You can find their
	distributions on vic.cc.purdue.edu in the pub/tools/unix/lsof/OLD
	subdirectory.

2.2	What about a new port?

	The 00PORTING file in the distribution gives hints on doing
	a port.  I will consider doing a port in exchange for
	permanent access to a test host.  I require permanent access
	so I can test new lsof revisions, because I will not offer
	distributions of dialect ports I cannot upgrade and test.

2.2.1	User-contributed Ports

	Sometimes I receive contributions of ports of lsof to
	systems where I can't test future revisions of lsof.  Hence,
	I don't incorporate these contributions into my lsof
	distribution.

	However, I do make these contributions available in the
	directory:

		pub/tools/unix/lsof/contrib

	on vic.cc.purdue.edu.

	Consult the 00INDEX file in the contrib/ directory for a
	list of the available contributions.

2.3	Why isn't there an AT&T SVR4 port?

	I haven't produced an AT&T SVR4 port because I haven't seen
	a UNIX dialect that is strictly limited to the AT&T System
	V, Release 4 source code.  Every one I have seen is a
	derivative with vendor additions.

	The vendor additions are significant to lsof because they
	affect the internal kernel structures with which lsof does
	business.  While some vendor derivatives of SVR4 are similar,
	each one I have encounted so far has been different enough
	from its siblings to require special source code.

	If you're interested in an SVR4 version of lsof, here are
	some existing ports you might consider:

		DC/OSx
		Reliant UNIX
		SCO UnixWare
		Sequent PTX
		Solaris

2.4	Why isn't there an SGI IRIX port?

	Lsof support for IRIX was terminated at lsof revision 4.36,
	because it had become increasingly difficult for me to
	obtain information on the IRIX kernel structures lsof needs
	to access.

	At IRIX 6.5 I decided the obstacles were too large for me
	to overcome, and I stoped supporting lsof on IRIX.  You'll
	find the sources for last revision of lsof (4.36) for IRIX
	via anonymous ftp at vic.cc.purdue.edu in:

	    pub/tools/unix/lsof/OLD/src/lsof_4.36.irix.tar.gz

	If you wish to pursue the issue, don't contact me, contact
	SGI.  This case was opened with SGI on the subject:

	    Case ID:	0982584
	    Category: Unix
	    Priority: 30-Moderate Impact

	    Problem Summary:
	    kernel structure header files needed for continued lsof
	    support

	    Problem Description:
	    Email In  07/17/98 19:09:23

	Dave Olson <olson@anchor.engr.sgi.com> of SGI welcomes
	email explaining why you want lsof and what it will do for
	you that available IRIX tools will not.


3.0	Lsof Problems

3.1	Why doesn't lsof report full path names?

	Lsof reports full path names in limited cases:  some systems
	-- e.g., some SunOS versions -- contain full directory path
	names in their user structure, so lsof reports those.
	
	Lsof reports the full path name when it is specified as a
	search argument for open files that match the argument.
	However, if the argument is a file system mounted-on
	directory, and lsof finds additional path name components
	from the kernel name cache, it will report them.

	Lsof reports path name for file system types that have path
	name lookup features-- e.g., AdvFS for Digital and Tru64
	UNIX; the Linux /proc-based lsof reports full path names,
	because the Linux /proc file system provides them.

	Otherwise, lsof uses the kernel name cache, where it exists
	and can be accessed, and reports some or all path name
	components (e.g., the sys and proc.h components of
	/usr/include/sys/proc.h) for these dialects:

		DC/OSx
		DEC OSF/1, Digital UNIX, Tru64 UNIX
		FreeBSD
		HP-UX
		NetBSD
		NEXTSTEP
		OpenBSD
		OpenStep
		Reliant UNIX
		SCO OpenServer
		SCO UnixWare
		Sequent PTX
		Solaris 2.x, 7, 8 BETA, and 8 BETA-Refresh
		SunOS 4.1.x
		Ultrix

	As far as I can determine, AFS path lookups don't share in
	kernel name cache operations, so lsof can't identify open
	AFS path name components.
	
	Since the size of the kernel name cache is limited and the
	cache is in constant flux, it does not always contain the
	names of all components in an open file's path; sometimes
	it contains none of them.

	Lsof reports the file system directory name and whatever
	components of the file's path it finds in the cache, starting
	with the last component and working backwards through the
	directories that contain it.  If lsof finds no path
	components, lsof reports the file system device name instead.

	When lsof does report some path components in the NAME
	column, it prefixes them with the file system directory
	name, followed by " -- ", followed by the components --
	e.g., /usr -- sys/path.h for /usr/include/sys/path.h.  The
	" -- " is omitted when lsof finds all the path name components
	of a file's name.

	Lsof can't obtain path name components from the kernel name
	caches of the following dialects:

	    AIX

	Only the Linux kernel records full path names in the
	structures it maintains about open files; instead, most
	kernels convert path names to device and node number doublets
	and use them for subsequent file references once files have
	been opened.

	To convert the device and node number doublet into a
	complete path name, lsof would have to start at the root
	node (root directory) of the file system on which the node
	resides, and search every branch for the node, building
	possible path names along the way.  That would be a time
	consuming operation and require access to the raw disk
	device (usually implying setuid-root permission).

	If the prospect of all that local disk activity doesn't
	concern you, think about the cost when the device is
	NFS-mounted.

3.1.1	Why do lsof -r reports show different path names?

	When you run lsof with its repeat (``-r'') option, you may
	notice that the extent to which it reports path names for
	the same files may vary from cycle to cycle.  That happens
	because other processes are making kernel calls affecting
	the cache and causing entries to be removed from and added
	to it.

3.1.2	Why does lsof report the wrong path names?

	Under some circumstances lsof may report an incorrect path
	name component, especially for files in a rapidly changing
	directory like /tmp.

	In a rapidly changing directory, like /tmp, if the kernel
	doesn't clear the cache entry when it removes a file, a
	new file may be given the same keys and lead lsof to believe
	that the old cache entry with the same keys belongs to the
	new file.

	Lsof tries to avoid this error by purging duplicate entries
	from its copy of the kernel name cache when they have the
	same device and inode number, but different names.

	This error is less likely to occur in UNIX dialects where
	the keys to the name cache are node address and possibly
	a capability ID.  The BSDI, Digital UNIX, FreeBSD, HP-UX,
	NEXTSTEP, OpenStep, PTX, SunOS, Solaris, Tru64 UNIX, Ultrix
	and UnixWare dialects use node address.  BSDI, FreeBSD,
	NetBSD, OpenBSD, Tru64 UNIX, and Ultrix also use a capability
	ID to further identify name cache entries.

3.1.3	Why doesn't lsof report path names for unlinked (rm'd) files?

	Lsof never reports a path names for a file that has been
	unlinked from its parent directory -- e.g., deleted via
	rm, or the unlink() system call -- even when some process
	may still hold the file open.  That's because the path name
	is erased from name caches and the parent directory file
	when the file is unlinked.

	Unlinked open files are sometimes used by applications for
	temporary, but invisible storage (i.e., ls won't show them,
	and no other process can open them.)  However, they may
	occasionally consume disk space to excess and cause concern
	for a system administrator, who will be unable to locate
	them with find, ls, du, or other tools that rely on finding
	files by examining the directory tree.

	By using lsof's +L option you can see the link count of
	open files -- in the NLINK column.  An unlinked file will
	have an NLINK value of zero.  By using the option +L1 you
	can tell lsof to display only files whose link count is
	less than one (i.e., zero).

3.2	Why is lsof so slow?

	Lsof may appear to be slow if network address to host name
	resolution is slow.  This can happen, for example, when
	the name server is unreachable, or when a Solaris PPP cache
	daemon is malfunctioning.

	To see if name lookup is causing lsof to be slow, turn it
	off with the ``-n'' option.

	Port service name lookup or portmapper registration lookup
	may also be causes of slow-down.  To suppress port service
	name lookup, specify -P.  Use -M to disable portmapper
	registration lookup.

	AIX lsof may be slow to start because of its oslevel identity
	comparison.  See the "Why does AIX lsof start so slowly?"
	and "Why does lsof warn "compiled for x ... y; this is z.?"
	sections for more information.

3.3	Why doesn't lsof's setgid or setuid permission work?

	If you install lsof on an NFS file system that has been
	mounted with the nosuid option, lsof may not be able to
	use the setgid or setuid permission you give it, complaining
	it can't open the kernel memory device -- e.g., /dev/kmem.

	The only solution is to install lsof on a file system that
	doesn't inhibit setgid or setuid permission.

3.4	Does lsof have security problems?

	I don't think so.  However, lsof does usually start with
	setgid permission, and sometimes with setuid-root permission.
	Any program that has setgid or setuid-root permission,
	should always be regarded with suspicion.

	Lsof drops setgid power, holding it only while it opens
	access to kernel memory devices (e.g., /dev/kmem, /dev/mem,
	/dev/swap).  That allows lsof to bypass the weaker security
	of access(2) in favor of the stronger checks the kernel
	makes when it examines the right of the lsof process to
	open files declared with -k and -m.  Lsof also restricts
	some device cache file naming options when it senses the
	process has setuid-root power.

	On a few dialects lsof requires setuid-root permission
	during its full execution in order to access files in the
	/proc file system.  These dialects include:

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

	When lsof runs with setuid-root permission it severely
	restricts all file accesses it might be asked to make with
	its options.

	The device cache file (typically .lsof_hostname in the home
	directory of the real user ID that executes lsof) has 0600
	modes.  (The suffix, hostname, is the first component of
	the host's name returned by gethostname(2).)  However, even
	when lsof runs setuid-root, it makes sure the file's
	ownerships are changed to that of the real user and group.
	In addition, lsof checks the file carefully before using
	it (See the question "How do I disable the device cache
	file feature or alter it's behavior?" for a description of
	the checks.); discards the file if it fails the scrutiny;
	complains about the condition of the file; then rebuilds
	the file.

	See the 00DCACHE file of the lsof distribution for more
	information about device cache file handling and the risks
	associated with the file.

3.5	Will lsof show remote hosts using files via NFS?

	No.  Remember, lsof displays open files for the processes
	of the host on which it runs.  If the host on which lsof
	is running is an NFS server, the remote NFS client processes
	that are accessing files on the server leave no process
	records on the server for lsof to examine.

3.6	Why doesn't lsof report locks held on NFS files?

	Generally lock information held by local processes on remote
	NFS files is not recorded by the UNIX dialect kernel.  Hence,
	lsof can't report it.

	One exception is some patch levels of Solaris 2.3, and all
	versions of Solaris 2.4 and above.  Lsof for those dialects
	does report on locks held by local processes on remotely
	mounted NFS files.

3.6.1	Why does lsof report a one byte lock on byte zero as a full
	file lock?
	
	When a process has a lock of length one, starting at byte
	zero, lsof can't distinguish it from a full file lock.
	That's because most UNIX dialects represent both locks the
	same way in their file lock (flock or eflock) structures.

3.7	Why does lsof report different values for open files on the
	same file system (the automounter phenomenon)?

	On UNIX dialects where file systems may be mounted by an
	automounter with the ``direct'' type, lsof may sometimes
	report difference DEVICE, SIZE/OFF, INODE and NAME values
	when asked to report files open on the file system.

	This happens because some files open on the file system --
	e.g., the current directory of a shell that changed its
	directory to the file system as the file system's first
	reference -- may be characterized in the kernel with
	temporary automounter node information.  The cd doesn't
	cause the file system to be mounted.

	A subsequent reference to the file system -- e.g., an ls
	of any place in it -- will cause the file system to be
	mounted.  Processes with files open to the mounted file
	system are characterized in the kernel with data that
	reflects the mounted file system's parameters.

	Unfortunately some kernels (e.g., some versions of Solaris
	2.x) don't revisit the process that did only a change-directory
	for the purpose of updating the data associated with the
	open directory file.  The file continues to be characterized
	with temporary automounter information until it does another
	directory change, even a trivial ``cd .''.

	Lsof will report on both reference types, when supplied
	the file system name as an argument, but the data lsof
	reports will reflect what it finds in the kernel.  For the
	different types lsof will display different data, including
	different major and minor device numbers in the DEVICE
	column, different lengths in the SIZE/OFF column, different
	node numbers in the INODE column, and slightly different
	file system names in the NAME column.

	In contrast, fuser, where available, can only report on
	one reference type when supplied the file system name as
	an argument.  Usually it will report on the one that is
	associated with the mounted file system information.  If
	the only reference type is the temporary automounter one,
	fuser will often be silent about it.

3.8	Why don't lsof and netstat output match?

	Lsof and netstat output don't match because lsof reports
	the network information it finds in open file system objects
	-- e.g., socket files -- while netstat often gets its
	information from separate kernel tables.

	The information available to netstat may describe network
	activities never or no longer associated with open files,
	but necessary for proper network state machine operation.

	For example, a TCP connection in the FIN_WAIT_[12] state
	may no longer have an associated open file, because the
	connection has been closed at the application layer and is
	now being closed at the TCP/IP protocol layer.

3.8.1	Why can't lsof find accesses to some TCP and UDP ports?

	Kernel implementations sometimes set aside TCP and UDP
	ports for communicating with support activities running in
	application layer servers -- the automountd and amd daemons,
	and the NFS biod and nfsd daemons are examples.  Netstat
	may report the ports are in use, but lsof doesn't.

	These kernel ports are not associated with file system
	objects, may be set aside by the kernel on demand, and
	sometimes are never released.  Because they aren't associated
	with open file system objects, they are transparent to
	lsof.  After all, lsof does stand for LiSt Open Files, and
	there are no open files associated with these kernel ports.

	I don't know a way to determine when ports reported by
	netstat but not by lsof are reserved by the kernel.

3.9	Why does lsof update the device cache file?

	At the end of the lsof output you may see the message:

	    lsof: WARNING: /Homes/abe/.lsof_vic was updated.

	In this message /Homes/abe/.lsof_vic is the path to the
	private device cache file for login abe.  (See 00DCACHE.)

	Lsof issues this message when it finds it necessary to
	recheck the system device directory (e.g., /dev or /devices)
	and rebuild the device cache file during the open file
	scan.  Lsof may need to do these things it finds that a
	device directory node has changed, or if it cannot find a
	device in the cache.

3.10	Why doesn't lsof report state for UDP socket files?

	Lsof reports UDP TPI connection state -- TS_IDLE, TS_BOUND,
	etc. -- for a limited set of dialects, including DC/OSx,
	Reliant UNIX, Solaris 2.x, 7, 8 BETA, 8 BETA-Refresh, and
	PTX.  TPI state is stream-based TCP/IP information that
	isn't available in many dialects.

	The general rule is if netstat(1) reports TPI state, lsof
	will too.

3.11	I am editing a file with vi; why doesn't lsof find the file?

	Vi doesn't have the file open.  It opens the file, makes
	a temporary copy (usually in /tmp or /usr/tmp), and does
	its work in that file.  When you update the file from vi,
	it reopens and rewrites the file.

	During the vi session itself, except for the brief periods
	when vi is reading or rewriting the file, lsof can't find
	an open reference to the file from the vi process, because
	there is none.

3.12	Why doesn't lsof report TCP/TPI window and queue sizes for my
	dialect?

	Lsof only reports TCP/TPI window sizes for Solaris, because
	only its netstat reports them.  The intent of providing
	TCP/TPI information in lsof NAME column output is to make
	it easier to match netstat output to lsof output.

	In general lsof only reports queue sizes for both TCP and
	UDP (TPI) connections on BSD-derived UNIX dialects, where
	both sets of values appear in kernel socket queue structures.
	SYSV-derived UNIX dialects whose TCP/IP implementations
	are based on streams generally provide only TCP queue sizes,
	not UDP (TPI) ones.

	While you may find that netstat on some SYSV-derived UNIX
	dialects with streams TCP/IP may report UDP (TPI) queue
	sizes, you will probably also find that the sizes are always
	zero -- netstat supplies a constant zero for UDP (TPI)
	queue sizes to make its headers align the same for TCP and
	UDP (TPI) connections.  Solaris seems to get it right --
	i.e., its netstat does not report UDP (TPI) queue sizes.

	When in doubt, I chose to avoid reporting UDP (TPI) queue
	sizes for UNIX dialects whose netstat-reported values I
	knew to be a constant zero or whose origin I couldn't
	determine.  Dialects in this category include DC/OSX,
	OSR, PTX, and Reliant UNIX.

3.13	What does "no more information" in the NAME column mean?

	When lsof can find no successor structures -- a gnode,
	inode, socket, or vnode -- connected to the file structure
	of an open descriptor of a process, it reports "no more
	information" in the NAME column.  The TYPE, DEVICE, SIZE/OFF,
	and INODE columns will be blank.

	Because the file structure is supposed to contain a pointer
	to the next structure of a file's processing support, if
	the pointer is NUL, lsof can go no further.

	Some UNIX dialects have file structures for system processes
	-- e.g., the sched process -- that have no successor
	structure pointers.  The "no more information" NAME will
	commonly appear for these processes in lsof output.

	It may also be the case that lsof has read the file structure
	while it is being assembled and before a successor structure
	pointer value has been set.  The "no more information" NAME
	will again result.

	Unless lsof output is filled with "no more information"
	NAME column messages, the appearance of a few should be no
	cause for alarm.

3.14	Why doesn't lsof find a process that ps finds?

	If lsof fails to display open files for a process that ps
	indicates exists, there may be several reasons for the
	difference.

	The process may be a "zombie" for which ps displays the
	"(defunct)" state.  In that case, the process has exited
	and has no open file information lsof can display.  It does
	still have a process structure, sufficient for the needs
	of ps.

	Another possible explanation is that kernel tables and
	structures may have been changing when lsof looked for the
	process, making lsof unable to find all relevant process
	structures.  Try repeating the lsof request.

3.15	Why doesn't -V report a search failure?

	The usual reason that -V won't report a search failure is
	that lsof located the search item, but was prevented from
	listing it by an option that doesn't participate in search
	failure reporting.

	For example, this lsof invocation:

		$ lsof -V -i TCP@foobar -a -d 999

	may not report that it can't find the Internet address
	TCP@foobar, even if there is an open file connected to that
	address, unless the open file also has a file descriptor
	number of 999 (the ``-a -d 999'' options).

3.16	Portmap problems

3.16.1	Why isn't a name displayed for the portmapper registration?

	When portmap registration reporting is enabled, any time
	there is a registration for a local TCP or UDP port, lsof
	displays it in square brackets, following the port number
	or service name -- e.g., ``:1234[name]'' or ``:name[100083]''.

	The TCP or UDP port number or service number (what follows
	the `:') is displayed under the control of the lsof -P
	option.  The registration identity is held by the portmapper
	and may be a name or a number, depending on how the
	registration's owner declared it.  Lsof reports what the
	port map holds and cannot derive a registration name from
	a registration number.

	Lsof can be compiled with registration reporting enabled
	or disabled by default, under the control of the HASPMAPENABLED
	#define (usually in machine.h).  The lsof help panel (`lsof
	-h`) will show the default.  Lsof is distributed with
	reporting disabled by default.

3.16.2	How can I display only portmap registrations?

	Lsof doesn't have an option that will display only TCP or
	UDP ports with portmap registrations.  The +M option only
	enables the reporting of registration information when
	Internet socket files are displayed; +M doesn't select
	the displaying of Internet socket files -- the -i option
	does that.

	This simple lsof pipe to grep will do the job:

		$ lsof -i +M | grep "\["

	This works because -i selects Internet socket files, +M
	enables portmap registration reporting, and only output
	lines with opening square brackets will have registrations.

	When portmapper registration reporting is enabled by default,
	because the lsof builder constructed it that way, +M is
	not necessary.  (The lsof help panel, produced with `lsof
	-h` will display the default portmapper registration
	reporting state.)  However, specifying +M when reporting
	is already enabled is acceptable, as is specifying -M when
	reporting is already disabled.

	Digression: lsof will accept `+' or `-' as a prefix to most
	options.  (That isn't documented in the man page or help
	panel to reduce confusion and complexity.)  The -i option
	is as acceptable as +i, so the above example could be
	written a little more tersely as:

		$ lsof +Mi | grep "\["
	
	But be careful to use the ``Mi'' ordering, since ``iM''
	implies M is an address argument to `i'.

3.16.3	Why doesn't lsof report portmap registrations for some ports?

	Lsof reports portmap registrations for local TCP and UDP
	ports only.  It identifies local ports this way:

	*  The port appears in the local address section of the
	   kernel structure that contains it.

	*  The port appears in the foreign address section of a
	   kernel structure whose local and foreign Internet
	   addresses are the same.

	*  The port appears in the foreign address section of a
	   kernel address structure whose Internet address is
	   INADDR_LOOPBACK (127.0.0.1).

	Following these rules, lsof ignores foreign portmapped
	ports.  That's done for reasons of efficiency and possible
	security prohibitions.  Contacting all remote portmappers
	could take a long time and be blocked by network difficulties
	(i.e., be inefficient).  Many firewalls block portmapper
	access for security reasons.

	Lsof may occasionally ignore portmap registration information
	for a legitimate local port by virtue of its local port
	rules.  This can happen when a port appears in the foreign
	part of its kernel structure and the local and foreign
	Internet addresses don't match (perhaps because they're on
	different interfaces), and the foreign Internet address
	isn't INADDR_LOOPBACK (127.0.0.1).

3.17	Why is `lsof | wc` bigger than my system's open file limit?

	There is a strong temptation to count files by piping lsof
	output to wc.  If your purpose is to compare the number
	you get to some Unix system parameter that defines the
	number of open files your system can have, resist the
	temptation.

	One reason is that lsof reports a number of "files" that
	don't occupy Unix file table space -- current working
	directories, root directories, text files, library files,
	memory mapped files are some.  Another reason is that lsof
	can report a file shared by more than one process that
	itself occupies only one file table slot.

	If you want to know the number of open files that occupy
	file table slots, use the +ff option and process the lsof
	output's FILE_ADDR column information with standard Unix
	tools like cut, grep, sed, and sort.

	You might also consider using use lsof's field output with
	+ff, selecting the file struct address with -FF, and
	processing the output with an AWK or Perl script.  See the
	list_fields.awk and list_fields.perl scripts in the scripts/
	subdirectory of the lsof distribution for hints on file
	struct post-processing filters.

3.18	Why doesn't lsof report file offset (position)?

	Lsof won't report a file offset (position) value if the -s
	option has been specified, or if the dialect doesn't support
	the displaying of file offset (position).

	That lsof is reporting only file size is indicated by the
	fact that the appropriate column header says SIZE instead
	of SIZE/OFF.

	If lsof doesn't support the displaying of file offset
	(position) -- e.g., for Linux /proc-based lsof -- the -h
	or -? output panel won't list the -o option.

3.19	Problems with path name arguments

3.19.1	How do I ask lsof to search a file system?

	You can ask lsof to search for all open files on a file
	system by specifying its mounted path name as an lsof
	argument -- e.g.,

	    $ lsof /

	Output of the mount command will show file system mounted
	path names.  It will also show the mounted-on device path
	for the file system.

	If the mounted-on device is a block device (the permission
	field in output of `ls -l <device>` starts with a `b/),
	you can specify it's name, too -- e.g.,

	    $ lsof /dev/sd0a

	If the mounted-on device isn't a block device -- for example,
	some UNIX dialects call a CD-ROM device a character device
	(ls output starts with a `c') -- you can force lsof to
	assume that the specified device names a file system with
	the +f option -- e.g.,

	    $ lsof +f -- /dev/sd0a
	
	(Note: you must use ``--'' after +f or -f if a file name
	follows immediately, because  +f and -f can be followed by
	characters that specify flag output selections.)

	When you use +f and lsof can't match the device to a file
	system, lsof will issue a complaint.

	The +f option may be used in some dialects to ask lsof to
	search for an NFS file system by its server name and server
	mount point.  If the mount application reports an NFS file
	system mounted-on value that way, then this sample lsof
	request should work.

	    $ lsof +f -- fleet:/home/fleet/u5

	Finally, you can use -f if you don't want a mounted file
	system path name to be considered a request to report all
	open files on the file system.  This is useful when you
	want to know if anyone is using the file system's mounted
	path name.  This example directs lsof to report on open
	access to the `/' directory, including when it's being used
	as a current working or root directory.

	    $ lsof -f -- /

	The lsof -f option performs the same function as -f does
	in some fuser implementations.  However, since the lsof -c
	option was chosen for another purpose before the `f' option
	was added to lsof, +f was selected as the analogue to the
	fuser -c option.  (Sorry for the potential confusion.)

3.19.2	Why doesn't lsof find all the open files in a file system?

	Lsof may not find all the open files in a file system for
	several reasons.

	First, some processes with files open on the file system
	may have been changing status when lsof examined the process
	table, and lsof "missed" them.  Remember, the kernel changes
	much faster than lsof can respond to the changes.

	Second, be sure you have specified the file system correctly.
	Perhaps you specified a file instead.  You can use lsof's
	-V option to have lsof report in detail on what it couldn't
	find.  Make sure the report for the file system you specified
	says "file system."  Here's some -V output:

	    $ /lsof -V /tmp ./lsof.h ./lsof
	    COMMAND  PID USER   FD   TYPE DEVICE SIZE/OFF  INODE NAME
	    lsof    2688  abe  txt   VREG 18,1,7  1428583 226641 ./lsof
	    lsof    2689  abe  txt   VREG 18,1,7  1428583 226641 ./lsof
	    lsof: no file use located: ./lsof.h

	You can also use lsof's +f option to force it to consider
	a path name as a file system.  If lsof can't find a file
	system by the specified name, it will issue a complaint --
	e.g.,

	    $ lsof +f -- /usr
	    lsof: not a file system: /usr
	
	(/usr is a directory in the / file system.)

3.19.3	Why does the lsof exit code report it didn't find open files
	when some files were listed?

	Sometimes lsof will list some open files, yet return a
	non-zero exit code, suggesting it hasn't found all the
	specified files.

	The first thing you should when you suspect lsof is incorrect
	is to repeat the request, adding the -V option.  In the
	resulting report you may find that your file system
	specification really wasn't a file system specification,
	just a file specification.

	Finally, if you specify two files or two file systems twice,
	lsof will credit all matches to the first of the two and
	believe that there were no matches for the second.  It's
	possible to specify a single file system twice with different
	path names by using both its mounted directory path name
	and mounted-one device name.

	    $ lsof +f -V spcuna:/sysprog /sysprog
	    COMMAND   PID USER   FD   TYPE DEVICE SIZE/OFF  INODE NAME
	    ksh     11092  abe  cwd   VDIR 39,0,1     1536 226562 /sysprog
	    (spcuna:/sysprog)
	    ...
	    lsof: no file system use located: spcuna:/sysprog
	
	All matches were credited to /sysprog; none to spcuna:/sysprog.

3.19.4	Why won't lsof find all the open files in a directory?

	When you give lsof a simple directory path name argument
	(not a file system mounted-on name), you are asking it to
	search for processes that have the directory open as a
	file, or as a process-specific directory -- e.g., root or
	current working directory.

	If you want to list instances of open files inside the
	directory, you need to specify the individual path names
	of those files, or use the lsof +D and +d options.

	See the answer to the question "Why are the +D and +d
	options so slow?" before you use +D or +d casually.

	See the answer to the question "Why do the +D and +d options
	produce warning messages?" for an explanation of some
	process authority limitations of +D and +d.

3.19.5	Why are the +D and +d options so slow?

	The +D and +d options cause lsof to build a path name search
	list for a specified directory.  +D causes lsof to descend
	the directory to its furthest subdirectory, while +d
	restricts it to the top level.  In both cases, the specified
	directory itself is included in the search list.  In both
	symbolic links are ignored.

	Building such a search list can take considerable time,
	especially when the specified directory contains many files
	and subdirectories -- lsof must call the system readlink()
	and stat() functions for each file and directory.  Storing
	the search list can cause lsof to use more than its normal
	amount of dynamic memory -- each file recorded in the search
	list consumes dynamic memory for its path name, characteristics,
	and search linkages.  Using the list means lsof must search
	it for every open file in the system.

	As an example of the load +D can impose, consider that an
	`lsof +D /` on a lightly loaded NeXT '040 cube with a 1GB
	root file system disk took 4+ minutes of real time.  It
	also generated several hundred error messages about files
	and directories the lsof process didn't have permission to
	access with stat(2).

	The bottom line is that +D and +d should be used cautiously.
	+D is more costly than +d for deeply nested directory trees,
	because of the full directory descent it causes.  So use
	+d where possible.

	In view of these warnings, when is it appropriate to use
	+D or +d?  Probably the most appropriate time is when you
	would specify the directory's contents to lsof with a shell
	globbing construct -- e.g., `lsof *`.  If that's what you
	need to do, `lsof +d .` is probably more efficient than
	having the shell produce a directory list, form it into an
	argument vector, and pass the vector to lsof for it to
	unravel.

	See the answer to the question "Why do the +D and +d options
	produce warning messages?" for an explanation of some
	process authority limitations of +D and +d.

3.19.6	Why do the +D and +d options produce warning messages?

	+D and +d option processing is limited by the authority of
	the lsof process -- i.e., lsof can only examine (with
	lstat(2) and stat(2)) files the owner of the process can
	access.

	If the ownership, group membership, or permissions of the
	specified directory, file within it, or directory within
	it prevents the owner of the lsof process from using lstat(2)
	or stat(2) on it, lsof will issue a warning message, naming
	the path and giving the system's (lstat(2's or stat(2)'s)
	reason (errno explanation text) for refusing access.

	As an example, assume user abc has a subdirectory in /tmp,
	owned by abc and readable, writable and searchable by only
	its owner.  If user def asks lsof to search for all /tmp
	references with +D or +d, lsof will be unable to lstat(2)
	or stat(2) anything in abc's private subdirectory, and will
	issue an appropriate warning.

	Lsof warnings can usually be suppressed with the -w option.
	However, using -w with +D or +d means that there will be
	no indication why lsof couldn't find an open reference to
	a restricted directory or something contained in it.

	Hint: if you need to use +D or +d and avoid authority
	warnings, and if you have super-user power, su and use lsof
	with +D or +d as root.

3.20	Why can't my C compiler find the rpcent structure definition?

	When you try to compile lsof your compiler may complain
	that the rpcent structure is undefined.  The complaints
	may look like this:

	    >print.c: In function `fill_portmap': 
	    >print.c:213: dereferencing pointer to incomplete type
	    >...

	The most likely cause is that someone has allowed a BIND
	installation to update /usr/include/netdb.h (or perhaps
	/usr/include/rpc/netdb.h), removing the rpcent structure
	definition that lsof expects to find there.

	Only Solaris has an automatic work-around.  (See dlsof.h
	in dialects/sun.).  The Solaris work-around succeeds because
	there is another header file, <rpc/rpcent.h>, with the rpcent
	structure definition, and there is a Solaris C pre-processor
	test that can tell when the BIND <netdb.h> is in place and
	hence <rpc/rpcent.h> must be included.

	Doubtlessly there are similar work-arounds possible in
	other UNIX dialects whose header files have been "touched"
	by BIND, but in general I recommend restoration of the
	vendor's <netdb.h> and any other header files BIND might
	have replaced.  (I think BIND replaces <resolv.h>,
	<sys/bitypes.h>, <sys/cdefs.h> -- and maybe others.)

3.21	Why doesn't lsof report fully on file "foo" on UNIX dialect
	"bar?"

	Lsof sometimes won't report much information on a given
	file, or may even report an error message in its NAME
	column.  That's usually because the file is of a special
	type -- e.g., in a file system specific to the UNIX dialect
	-- and I haven't used a system where the file appeared
	during my testing.

	If you encounter such a situation, send me e-mail and we
	may be able to devise an addition to lsof that will report
	on the file in question.

3.22	Problems loading and executing lsof

3.22.1	Why do I get a complaint when I execute lsof that some library
	file can't be found?

	On systems where the LIBPATH (or the equivalent) environment
	variable is used to record the library search path in
	executable files when they are built, an incorrect value
	may make it impossible for the system to find the shared
	libraries needed to load lsof for execution.

	This may be particularly true on systems like AIX >= 4.1.4,
	where the lsof Makefile takes the precautionary step of
	using the -bnolibpath loader flag to insure that the path
	to the private static lsof library is not recorded in the
	lsof binary.  Should LIBPATH be invalid when lsof is built,
	it will be recorded in the lsof binary as the default
	library path search order and lead to an inability to find
	libraries when lsof is executed.

	So, if you get missing library complaints when you try to
	execute lsof, check LIBPATH, or whatever environment variable
	is used on your system to define library search order in
	executable files.  Use the tools at your disposal to look
	at the library paths recorded in the lsof binary -- e.g.,
	chatr on HP-UX, dump on AIX, ldd on Solaris.

	Make sure, too, that when the correct library search path
	has been recorded in the executable file, the required
	library files exist at one or more of the search paths.


3.22.2	Why does lsof complain it can't open files?

	When lsof begins execution, unless it has been asked to
	report only help or version information, typically it will
	attempt to access kernel memory and symbol files -- e.g.,
	/unix, /dev/kmem.  Even though lsof needs only permission
	to open these files for reading, read access to them might
	be restricted by ownerships and permission modes.

	So the first step to diagnosing lsof problems with opening
	files is to use ls(1) to examine the ownerships and permission
	modes of the files that lsof wants to open.  You may find
	that lsof needs to be installed with some type of special
	ownership or permission modes to enable it to open the
	necessary files for reading.  See the Installing Lsof
	section of 00README for more information.

3.22.3	Why does lsof warn "compiled for x ... y; this is z."?

	Unless warnings are suppressed (with -w) or the kernel
	identity check symbol (HASKERNIDCK) definition has been
	deleted, all but one lsof dialect version (exception:
	/proc-based Linux lsof) compare the identity of the running
	kernel to that of the one for which lsof was constructed.
	If the identities don't match, lsof issues a warning like
	this:

	    lsof: WARNING: compiled for Solaris release 5.7; this is 5.6.

	Three kernel identity differences can generate this warning
	-- the version number, the release number, and the architecture
	type.  Not all are compared for every dialect version;
	architecture type is only compared for SunOS, for example.

	Build and running identity differences are usually significant,
	because they usually indicate kernels whose structures are
	different -- kernel structures commonly change at dialect
	version releases.  Since lsof reads data from the kernel
	in the form of structures, it is sensitive to changes in
	them.  The general rule is that an lsof compiled for one
	UNIX dialect version will not work correctly when run on
	a different version.

	There are three work-arounds: 1) use -w to suppress the
	warning -- and risk missing other warnings; 2) permanently
	disable the identity check by deleting the definition of
	HASKERNIDCK in the dialect's machine.h header file -- with
	the same risk; or 3) rebuild lsof on the system where it
	is to be run.  (Deleting HASKERNIDCK can be done with the
	Customize script or by editing machine.h.)

	Generally checking kernel identity is a quick operation
	for lsof.  However, it is potentially slow under AIX, where
	lsof must run /usr/bin/oslevel.  To speed up lsof, use -w
	to suppress the /usr/bin/oslevel test.  See "Why does AIX
	lsof start so slowly?" for more information.

3.22.4	How can I disable the kernel identity check?

	The kernel identity check is controlled by the HASKERNIDCK
	definition.  When it is defined, most dialects (exclusion:
	/proc-based Linux lsof) will compare the build-time kernel
	identity with the run-time one.

	To disable the kernel identity check, disable the HASKERNIDCK
	definition in the dialect's machine.h header file.  The
	Customize script can be used to do that in its section
	about the kernel identity check.

	Caution: while disabling the kernel identity check may
	result in smaller lsof startup overhead, it comes with the
	risk of executing an lsof that may produce warning messages,
	error messages, incorrect output, or no output at all.

3.23	Why don't ps(1) and lsof agree on the owner of a process?

	Generally the user ID lsof reports in its USER column is
	the process effective user ID, as found in the process
	structure.  Sometimes that may not agree with what ps(1)
	reports for the same process.

	There are sundry reasons for the difference.  Sometimes
	ps(1) uses a different source for process information,
	e.g., the /proc file system or the psinfo structure.
	Sometimes the kernel is lax or confused (e.g., SunOS 4.1.x
	or Solaris 2.5.1) about what ID to report as the effective
	user ID.  Sometimes the system carries only one user ID in
	its process structure (some BSD derivatives), leaving lsof
	no choice.

	The differences between lsof and ps(1) user identifications
	should be small and normally it will be apparent that the
	confusion is over a process whose application has changed
	to an effective user ID different from the real one.

3.24	Why doesn't lsof find an open socket file whose connection
	state is past CLOSE_WAIT?

	TCP/IP connections in states past CLOSE_WAIT -- e.g.,
	FIN_WAIT_1, CLOSING, LAST_ACK, FIN_WAIT_2, and TIME_WAIT
	-- don't always have open files associated with them.  When
	they don't, lsof can't identify them.  When the connection
	state advances from CLOSE_WAIT, sometimes the open file
	associated with the connection is deleted.

3.25	Why don't machine.h definitions work when the surrounding
	comments are removed?

	The machine.h header files in dialect subdirectories have
	some commented-out definitions like:

	    /* #define HASSYSDC "/your/choice/of/path */

	You can't simply remove the comments and expect the definition
	to work.  That's intended to make you think about what
	value you are assigning to the symbol.  The assigned value
	might have a system-specific convention.  HASSYSDC, for
	example, might be /var/db/lsof.dc for FreeBSD, but it might
	be /var/adm/lsof.dc for Solaris.

	Symbols defined in the lsof documentation are described in
	00PORTING, other machine.h comments, and other lsof
	documentation files.  HASSYSDC, for example, is discussed
	in 00DCACHE.  When comments and documentation don't suffice,
	consult the source code for hints on how the symbol is
	used.


4.0	AIX Problems

4.1	What is the Stale Segment ID bug and why is -X needed?

	Kevin Ruderman <rudi@acs.bu.edu> reports that he has been
	informed by IBM that processes using the AIX 3.2.x,
	4.1[.12345]], and 4.2[.1] kernel's readx() function can
	cause other AIX processes to hang because of what appears
	to be file system corruption.

	This failure, known as the Stale Segment ID bug, is caused
	by an error in the AIX kernel's journalled segment memory
	handler that causes the kernel's dir_search() function
	erroneously to believe directory entries contain zeroes.
	The process using the readx() call need not be doing anything
	wrong.  Usually the system must be under such heavy load
	that the segment ID being used in the readx() call has been
	freed and then reallocated to another process since it was
	obtained from kernel memory.

	Lsof uses the readx() function to access library entry
	structures, based on the segment ID it finds in the proc
	structure of a process.  Since IBM probably will never fix
	the kernel bug, I've added an AIX-specific option to lsof
	that controls its use of the readx() function.
	
	By default lsof readx() use is disabled; specifying the
	``-X'' option enables readx() use.

	If you want to change the default readx() behavior of AIX
	lsof, change the HASXOPT, HASXOPT_ROOT, and HASXOPT_VALUE
	definitions in dialects/aix/machine.h.  You can also use
	these definitions to enable or disable readx() -- consult
	the comments in machine.h.  You may want to disable readx()
	use permanently if you plan to make lsof publicly executable.

	When HASXOPT_ROOT is defined, lsof will restrict use of
	the -X option to processes whose real UID is root; if
	HASXOPT_ROOT isn't defined, any user may specify the -X
	option.  The Customize script offers the option to change
	HASXOPT_ROOT when HASXOPT is defined and HASXOPT_ROOT is
	named in any dialect's machine.h header file.

	I have never seen lsof cause a problem with its use of
	readx(), but I believe there is some chance it could, given
	the right circumstances.

4.1.1	Stale Segment ID APAR

	Here are the details of the Stale Segment ID bug and IBM's
	response, provided by Kevin Ruderman <rudi@acs.bu.edu>.

	AIX V3
	  APAR=ix49183
	      user process hangs forever in kernel due to file
	      system corruption
	  STAT=closed prs  TID=tx2527 ISEV=2 SEV=2
	       (A "closed prs" is one closed with a Permanent
	       ReStriction.)
	  RCOMP=575603001 aix v3 for rs/6 RREL=r320

	AIX V4  (internal defect, no apar #)
	  prefix        p
	  name          175671
	  abstract      KERMP: loop for ever in dir_search()

	Problem description:

	1. Some user application -- e.g., lsof -- gets the segment
	   ID (SID) for the process private segment of a target
	   process from the process table.

	2. The target process exits, deleting the process private
	   segment.

	3. The SID is reallocated for use as a persistent segment.

	4. The user application runs again and tries to read the
	   user area structure from /dev/mem, using the SID it read
	   from the process table.

	5. The loads done by the driver for /dev/mem cause faults
	   in the directory; new blocks are allocated; the size
	   changed; and zero pages created.

	6. The next application that looks for a file in the affected
	   directory hangs in the kernel's dir_search() function
	   because of the zero pages.  This occurs because the
	   kernel's dir_search() function loops through the variable
	   length entries one at a time, moving from one to the
	   next by adding the length of the current entry to its
	   address to get the address of the next entry. This
	   process should end when the current pointer passes the
	   end of the known directory length.

	   However, while the directory length has increased, the
	   entry length data has not, so when dir_search() reaches
	   the zero pages, it loops forever, adding a length of
	   zero to the current pointer, never passing the end of
	   the directory length.  The application process is hung;
	   it can't be killed or stopped.

	IBM closed the problem with a PRS code (Permanent ReStriction)
	under AIX Version 3 and had targeted a fix for AIX 4.2.  They
	have recently (I became aware of it September 10, 1996)
	cancelled the defect report altogether and have indicated they
	are not going to fix the defect.

4.2	Gcc Work-around for AIX 4.1x

	When gcc is used to compile lsof for AIX 4.1x, it doesn't
	align one element of the user structure correctly.  Xlc
	sees the U_irss element as a type "long long" and aligns
	it on an 8 byte boundary.  That's because the default mode
	of xlc is -qlonglong; when -qlonglong is enabled, the
	_LONG_LONG symbol is also defined.

	Gcc sees U_irss as a two element array of type long, because
	_LONG_LONG isn't defined.  Hence gcc aligns the U_irss
	element array on a 4 byte boundary, rather than an 8 byte
	one, making the gcc incantation of the user structure 4
	bytes shorter than xlc's.

	When the length of gcc's user structure is supplied as
	argument 4 to the undocumented getuser() function of the
	AIX kernel, getuser() rejects it as an incorrect size and
	returns EINVAL.

	Lsof has a work-around for this problem.  It involves a
	special test in the Configure script when the "aixgcc"
	Configure abbreviation is used -- e.g.,

		$ Configure -n aixgcc

	The test is to compile a small program with gcc and check
	the alignment of U_irss.  If it's not aligned on an 8 byte
	boundary, the Configure script makes a special copy of
	<sys/user.h> in ./dialects/aix/aix<AIX_version> whose
	U_irss will align properly, and generates compile time
	options to use it.

	While I have tested this work-around only with 4.1.4, it
	should work with earlier versions of AIX 4.1.  It does not
	work for AIX 4.2; a different work-around is employed there.
	(See the next section.)

	If you want to use this technique to compile other AIX
	4.1x programs with gcc for using getuser(), check the
	Configure script.

	Stuart D. Gathman <stuart@bmsi.com> identified this gcc
	AIX alignment problem.

4.3	Gcc and AIX 4.2[.1]

	Alignment problems with gcc and AIX 4.2[.1] inside the user
	structure are more severe, because there are some new 64
	bit types in AIX that gcc doesn't yet (as of 2.7.x) support.
	The <sys/user.h> U_irss element problem, discussed in 4.3
	above, doesn't exist in 4.2[.1].

	The AIX lsof machine.h header file has a work-around,
	provided by Henry Grebler <henryg@optimation.com.au>, that
	bypasses gcc alignment problems.  Later versions of gcc
	(e.g., 2.8.x) will probably bypass the problems as well.

4.4	Why won't lsof's Configure allow the use of gcc for AIX
	below 4.1?

	Gcc can't reliably be used to compile lsof for AIX versions
	below AIX 4.1 because of possible kernel structure element
	alignment differences between it and xlc.

4.5	What is an AIX SMT file type?

	When you run AIX X clients with the DISPLAY environment
	variable set to ``:0.0'' they communicate with the AIX X
	server via files whose kernel file structure has an undefined
	type (f_type == 0xf) -- at least there's no definition for
	it in <sys/file.h>.

	These are Shared Memory Transport (SMT) sockets, an artifact
	of AIXWindows, designed for more efficient data transfers
	between the X server and its clients.

	Henry Grebler <henryg@optimation.com.au> and David J. Wilson
	<davidw@optimation.com.au> alerted me to the existence of
	these files.  Mike Feldman <feldman@charm.urbana.mcd.mot.com>
	and others helped me identify them as SMT sockets.

	The curious reader can find more about SMT sockets in
	/usr/lpp/X11/README.SMT.

4.6	Why does AIX lsof start so slowly?

	When AIX lsof starts it compares the running kernel's
	identity to the one for which it was built, using
	/usr/bin/oslevel.  That comparison can sometimes take a
	long time to complete, depending on the system's maintenance
	level and how recently it was examined with oslevel.

	You can skip the oslevel test by suppressing warning messages
	with lsof's -w option.  Doing that carries with it the risk
	of missing other warning messages, however.

	You can also disable the kernel identity check by disabling
	the definition of the HASKERNIDCK symbol by editing AIX
	machine.h header file or by using the Customize script to
	disable it.

	See the "Why does lsof warn "compiled for x ... y; this is
	z.?" section for more information.

4.7	Why does exec complain it can't find libc.a[shr.o]?

	When you try to execute lsof you may get this complaint:

	    exec(): 0509-036 Cannot load program ./lsof because of
		        the following errors:
		    0509-022 Cannot load library libc.a[shr.o].
		    0509-026 System error: A file or directory in
			the path name does not exist.

	This is probably the result of making lsof when the LIBPATH
	environment variable contained a directory path that doesn't
	contain libc.a.  You can see what LIBPATH contained when
	lsof was made by using the dump application on lsof.  For
	example, if LIBPATH contained /foo/bar when lsof was made,
	you will see this (partial) dump output:

	    $ dump -H lsof
	    ...
			***Import File Strings***
	    INDEX  PATH                          BASE         ...
	    0      /foo/bar

	To correct the problem, revisit the lsof source directory
	and remake lsof this way:

	    $ unset LIBPATH; make		(sh or ksh)
	or
	    % unsetenv LIBPATH; make		(csh or tcsh)

	
5.0	BSD/OS BSDI Problems

5.1	Why doesn't lsof report on open kernfs files?

	Lsof doesn't report on open BSD/OS BSDI kernfs files because
	the structures lsof needs aren't defined in the kernfs.h
	header file in /sys/misc/kernfs.


6.0	DEC OSF/1, Digital UNIX, and Tru64 UNIX Problems

6.1	Why does lsof complain about non-existent /dev/fd entries?

	When you run lsof for Digital UNIX 3.2, lsof may complain:

	    lsof: can't lstat /dev/fd/xxx: No such file or directory
	    lsof: can't lstat /dev/fd/yyy: No such file or directory

	(Or it may warn about other missing /dev/fd paths.)  When
	you do an ``ls /dev/fd'' none of the missing paths are listed.

	This is caused by a bug in the DEC library function
	getdirentries().  For some reason, when /dev/fd is a file
	system mount point, getdirentries() returns an incorrect
	size for it to readdir().  (Lsof calls readdir() in its
	ddev.c readdev() function.)  Because of the incorrect size,
	readdir() goes past the end of the /dev/fd directory buffer,
	encounters random paths and returns them to lsof.  Lsof
	then attempts to lstat(2) the random paths, gets error
	replies from lstat(2), and complains about the paths.

	Duncan McEwan <duncan@Comp.VUW.AC.NZ> discovered this error
	and has reported it to DEC.  Duncan also supplied a work-
	an alternate readdir() function as a work-around.  I've
	incorporated his readdir() in dialects/osf/ddev.c (as the
	static ReadDir() function) with some slight modifications,
	and enabled its use when the USELOCALREADDIR symbol is
	defined.

	The Configure script defines USELOCALREADDIR for Digital
	UNIX version and 3.2.  If you don't want to use Duncan's
	local readdir() function, edit the Makefile and remove
	-DUSELOCALREADDIR from the CFGF string.  When DEC releases
	a corrected getdirentries() function, I'll modify the
	Configure script to stop defining USELOCALREADDIR.

6.2	Why does the Digital UNIX V3.2 ld complain about Ots* symbols?

	When you compile lsof on your Digital UNIX V3.2 system, ld
	may complain:

	    ld:
	    Unresolved:
	    knlist
	    _OtsRemainder32Unsigned
	    _OtsDivide64Unsigned
	    _OtsRemainder64Unsigned
	    _OtsDivide32Unsigned
	    _OtsMove
	    _OtsDivide32
	    _OtsRemainder32
	    *** Exit 1

	I'm not sure why this happens, nor do I think it happens
	on all Digital UNIX V3.2 systems.  However, I have had one
	report about it.

	The best work-around seems to be to remove -lmld from the
	CFGL string in the Makefile produced by Configure -- i.e.,
	change:

	    CFGL=    -lmld
	to
	    CFGL=

	According to the V3.2 man page for nlist(3), this shouldn't
	work, but my testing shows that it does.  Although I haven't
	been able to test this second work-around, you might try
	adding -lots to CFGL, rather than removing -lmld -- i.e.,
	change:

	    CFGL=    -lmld
	to
	    CFGL=    -lmld -lots

	WARNING: my testing also shows that the V2.0 nlist(3) man
	page means what it says when it calls for -lmld -- lsof
	loaded without -mld under V2.0 can't locate the proc
	(process) table address.

	    DON'T REMOVE -lmld FROM THE DIGITAL UNIX V2.0 MAKEFILE.

	If you run into this problem, please let me know what
	problem you encountered and how you solved it.

6.3	Why can't lsof locate named pipes (FIFOs) under V3.2?

	While lsof for V3.2 can report on named pipes (FIFOs), it
	can't find them by name.  That appears to happen because
	of the way the V3.2 kernel lstat(2) function reports named
	pipe device numbers.

	The V3.2 kernel reports the device number as 0xfffffff,
	while the kernel structures for named pipes that lsof
	examines contain the device number of the file system on
	which the named pipe resides.

	Consequently, lsof can't match the device and inode number
	pair it receives from applying lstat(2) to the named pipe
	with any device and inode number pair it finds when scanning
	kernel structures.

	I don't have a work-around.  You can, of course, ask for
	full lsof output and use a post-processing filer (e.g.,
	grep) to locate the named pipe of interest.

	This problem doesn't exist under V2.0.

6.4	Why does lsof use the wrong configuration header files?
	For example, why can't the lsof compilation find cpus.h?

	DEC OSF/1, Digital UNIX, and Tru64 UNIX configuration header
	files describe the hardware and software environment for
	which your kernel boot file was constructed.  For example,
	/sys/<name>/cpus.h defines the number of CPUs in its NCPUS
	#define.

	Lsof searches for the configuration header file subdirectory
	in /sys (/usr/sys for Digital UNIX version 4.0 and Tru64
	UNIX) by converting the first host name component to capital
	letters -- e.g., TOMIS is derived from tomis.bio.purdue.edu.
	If that subdirectory exists, lsof uses header files from
	it.  (Configure reports what subdirectory is being used.)

	If Configure doesn't find a host-name derived subdirectory,
	it prompts you for the entry of a subdirectory name.  If
	you can't find one, quit Configure and run the kernel
	generation process to create a proper configuration sub-
	directory.  If you don't identify a proper configuration
	subdirectory and you try to compile lsof, the compiler will
	complain about missing header files -- e.g., a missing
	cpus.h.

	Once you have located or generated a proper configuration
	subdirectory, rerun Configure.  If you have generated a
	configuration subdirectory whose name is derived from the
	host name, Configure will find and use it.  If not, you
	will have to specify its name to Configure.


7.0	FreeBSD Problems

7.1	Why doesn't lsof report on open kernfs files?

	Lsof doesn't report on open FreeBSD kernfs files because
	the structures lsof needs aren't defined in the kernfs.h
	header file in /sys/misc/kernfs.

7.2	Why doesn't lsof work under FreeBSD 4.0?

	If lsof doesn't work under FreeBSD 4.0, first make sure
	you have the latest lsof revision, 4.41 or higher.

	Next check that your kernel and libkvm are in proper
	synchronization.  Recompile them, if necessary.

	You might also try compiling lsof this way:

	    $ make DEBUG="-O -DCOMPAT_LINUX_THREADS"

	Strictly speaking, -DCOMPAT_LINUX_THREADS shouldn't be
	needed, but slightly unsynchronized FreeBSD 4.0 kernels,
	header files, and libraries may make it necessary.


8.0	HP-UX Problems

8.1	Why doesn't an HP-UX lsof compilation use -O?

	If you only have the standard (bundled) HP-UX C compiler
	and haven't purchased and installed the optional one, then
	you can't use cc's -O option.  The HP-UX cc(1) man page
	says this:

	  "Options
	     Note that in the following list, the cc and c89 options
	     -A , -G , -g , -O , -p , -v , -y , +z , and +Z are
	     not supported by the C compiler provided as part of
	     the standard HP-UX operating system.  They are supported
	     by the C compiler sold as an optional separate product."

	Lsof's Configure script tries to detect what C compiler
	product you have installed by examining your compiler.  If
	that examination reveals a standard (bundled) compiler,
	lsof avoids using -O.

	If the Configure compiler test fails, the C compiler will
	complain that it doesn't support -O.  You can suppress that
	complaint by editing the Makefile produced by Configure
	and removing the

	    DEBUG=	-O
	
	make string.

8.2	Where is x25L3.h under HP-UX 9.x?

	If you try to compile lsof with CCITT support under HP-UX
	9.x, the compiler will complain it can't find the x25L3.h
	header file.  While that header file was shipped with HP-UX
	8.x releases, it is missing from 9.x.

	If you have access to an 8.x system, you can copy the
	x25L3.h header file from its /etc/conf/x25 directory to
	the same place on your 9.x system.  If you can't do that,
	you'll have to appeal to HP or to an 8.x user who can supply
	that header file.

	You can disable HP-UX CCITT support by editing the Makefile
	the Configure script generates.  Delete the DINC string
	and remove ``-DHPUX_CCITT'' from CFGF.

	My thanks go to Pasi Kaara <ppk@atk.tpo.fi> for this
	information.

8.3	Why doesn't lsof report all HP-UX 9.x locks?

	Lsof can't report on HP-UX 9.x locks. created via the
	fcntl() system call, because the information about them is
	not stored in structures known to lsof.  Locks so created
	appear to work correctly, the problem is that lsof can't
	find how they're reported in the file and node structures
	for the locking process.

	Lsof has no similar trouble finding information on locks
	created with the lock() system call.  It finds information
	about them in the locklist structure, attached to the file's
	inode.

	I'm at a loss to find the fcntl() lock information.  It
	can be found in HP-UX 10.[12]0, in locklist structures,
	attached to the vnode, although the 10.20 locklist structure
	is incorrect.  (See the next section.)

8.4	Why doesn't lsof report HP-UX 10.20 locks correctly?

	Lsof doesn't report the length of HP-UX 10.20 locks -- byte
	or full file -- correctly under HP-UX 10.20 because the
	kernel structure lsof examines to determine that a process
	has a lock on a vnode (the locklist structure from
	<sys/vnode.h>) contains incorrect lock start and end byte
	values.
	
	Even though this appears to be a kernel bug, HP-UX locks
	seem to work correctly.  All I can conclude is that the
	correct lock information is stored somewhere else in the
	kernel, in a place not visible to lsof.

	As a consequence of this incorrect locklist structure
	information, lsof always reports all locks with a byte-level
	`r' (read) or `w' (write) lock indication, and never reports
	a full-file read (`R') or write (`W') lock.

8.5	Why doesn't the CCITT support work under 10.x?

	Pasi Kaara <Pasi.Kaara@atk.tpo.fi>, who originally provided
	the HP-UX CCITT support, reports that it no longer works
	under HP-UX 10.x.  Consequently, at lsof revision 4.02 it
	has been disabled.

8.6	Why can't lsof be compiled with `cc -Aa` or `gcc -ansi` under
	HP-UX 10.x?

	Some HP-UX 10.x header files, needed by lsof, can't be
	compiled properly in ANSI_C mode; structure element definition
	and alignment problems result.  The f_offset member of the
	file structure, for example, is incorrect.

	This ANSI-C obstacle extends to using the -Aa option of
	the HP C compiler and the -ansi option of gcc.

8.7	Why does lsof complain about no C compiler?

	Lsof's Configure script looks in /bin and /usr/ccs/bin for
	an HP C compiler, because it needs to know if the compiler
	is the standard (bundled) one or the optional separate
	product.  If it finds no compiler in either place, Configure
	quits after complaining:

	    No executable cc in /bin or /usr/ccs/bin

	If you don't have a C compiler in either of these standard
	places, you should consider installing it.  If you have
	gcc installed, you can use it by declaring the ``hpuxgcc''
	abbreviation to lsof's Configure script.

	If you have a C compiler in a non-standard location, you
	can use the HPUX_CCDIR[12] environment variables to name
	the path to it.  Consult the 00XCONFIG file of the lsof
	distribution for more information.

8.8	Why does Configure complain about q4 for HP-UX 11?

	When you run Configure on an HP-UX 11 system, it may complain:

	  !!!ERROR!!!     !!!ERROR!!!     !!!ERROR!!!     !!!ERROR!!!
	  Configure can't use /usr/contrib/bin/q4 to examine the ipis_s
	  structure.  You must do that yourself, report the result in
	  the HPUX_IPC_S_PATCH environment variable, then repeat the
	  Configure step.  Consult the Configure script's use of
	  /usr/contrib/bin/q4 and the 00XCONFIG file for information
	  on ipis_s testing and the setting of HPUX_IPC_S_PATCH.
	  !!!ERROR!!!     !!!ERROR!!!     !!!ERROR!!!     !!!ERROR!!!

	This message states that Configure cannot use the q4 from
	/usr/contrib/bin to examine the kernel's boot image for
	the ipis_s structure.  That structure was introduced as
	far as I can tell in early 1999.  Patch bundle B.11.00.43
	appears to have the patch, but I can't identify the patch
	more specifically than that.

	Note: q4 may also fail if it can't execute nm -- e.g., it
	can't find /usr/bin/nm, or you have a conflicting, private
	version of nm eariler in your path.

	The ipis_s structure isn't described in any header file
	HP-UX releases with HP-UX 11.  It appears in the private
	lsof header file .../dialects/hpux/kmem/hpux11/ipc_s.h.
	I had to create ipc_s.h during the lsof port to HP-UX 11
	by using q4.  Lsof gets local and remote connection addresses
	(IP and port numbers) from ipc_s, so an incorrect ipc_s
	definition will cause incorrect reporting of TCP/IP connection
	addresses.

	Over the long run -- e.g., after the current patch has been
	replaced by yet another one -- using q4 is the most reliable
	way to tell if ipis_s exists and what it contains.

	Unfortunately, q4 needs to be installed in /usr/contrib/bin
	and the kernel boot image, /stand/vmunix, needs to be
	processed with pxdb.  If either is untrue, lsof issues the
	above error message, perhaps preceded by q4 messages.  For
	example, if /stand/vmunix hasn't been processed by pxdb,
	the q4 messages will include:

	    q4: (error) vmunix not pxdb'd
	or
	    q4: (warning) /stand/vmunix has not been processed by pxdb.

	To be able to complete HP-UX configuration of lsof, you
	must determine if the ipis_s structure is defined in your
	kernel, if the ipis_s structure of your kernel has an
	ipis_msgsqueued member, and if the ipc_s structure of your
	kernel uses has an ipc_ipis member.  That means you may
	have to process /stand/vmunix with pxdp, and perhaps install
	q4 and run it on /stand/vmunix.

	If you must run q4 to determine the state of ipis_s and
	ipc_s, use these q4 commands:

	    $ /usr/contrib/bin/q4 /stand/vmunix
	    ...
	    q4> fields -c struct ipis_s
	    ...
	    q4> fields -c struct ipc_s

	Look in the q4 output for the ipc_ipis member of the ipc_s
	structure, and look in the ipis_s structure for the
	ipis_msgsqueued member.  If ipc_s has ipc_ipis but ipis_s
	lacks ipis_msgsqueued, set HPUX_IPC_S_PATCH environment
	variable to "1".  If ipc_s has ipc_ipis and ipis_s has
	ipis_msgsqueued, set HPUX_IPC_S_PATCH to "2" -- e.g.,

	    $ HPUX_IPC_S_PATCH=1 Configure -n hpux
	  or
	    $ HPUX_IPC_S_PATCH=2 Configure -n hpux
	  or
	    % setenv HPUX_IPC_S_PATCH 1
	    % Configure -n hpux
	  or
	    % setenv HPUX_IPC_S_PATCH 2
	    % Configure -n hpux

	(Use setenv if your shell is csh.)

	If ipc_s has no ipc_ipis member, set HPUX_IPC_S_PATCH
	to "N" -- e.g., use this Configure step:

	    $ HPUX_IPC_S_PATCH=N Configure -n hpux
	or
	    % setenv HPUX_IPC_S_PATCH N
	    % Configure -n hpux

9.0	Linux

9.1	What do /dev/kmem-based and /proc-based lsof mean?

	At approximately Linux 2.1.72 and exactly at lsof revision
	4.23 support for Linux forks.  The first fork, containing
	the oldest lsof form is based on access to kernel memory
	structures, and is called /dev/kmem-based lsof.  A
	/dev/kmem-based lsof is heavily intertwined with the Linux
	kernel version, its header files, and its system map file.
	Typically a /dev/kmem-based lsof needs only setgid permission
	to local all open file information.

	After approximately Linux 2.1.72 and at revision 4.23 lsof
	obtains all its information from the /proc file system.
	That lsof is called the /proc-based lsof.  A /proc-based
	lsof does not read kernel memory, needs neither kernel
	header files nor the system map file, and is less likely
	to be affected by Linux kernel changes.  However, it does
	require setuid-root permission to list all open files, and
	it can't report file offsets (positions).

	The lsof Configure script automatically determines which
	type of lsof it will activate.  The sources for both lsof
	types reside in subdirectories of .../dialects/linux; the
	/dev/kmem-based sources in .../dialects/linux/kmem; the
	/proc-based, in .../dialects/linux/proc.

	Configure determines which sources to use by testing the
	presence of files and file contents in /proc, so the exact
	Linux kernel version at which Configure activates /proc-based
	lsof may differ slightly from 2.1.72, the version where I
	developed /proc-based lsof.  (I know the /proc-based lsof
	does not find the information it needs in the Linux version
	2.0.32 /proc.)

9.2	/dev/kmem-based Linux lsof Questions

9.2.1	Why doesn't /dev/kmem-based lsof work (or even compile) on my
	Linux system?

	I test lsof on what Linux systems are available to me.
	Currently my tests systems are provided by Jim Mintha
	<jim@geog.ubc.ca> and Jonathan Sergent <sergent@purdue.edu>.

	If lsof doesn't even compile on your Linux system, you may
	be using a version of Linux whose header files differ from
	the ones I used.  Or you may not have installed /usr/src/linux,
	and lsof can't find header files that it needs from that
	directory.

9.2.1.1	Why does /dev/kmem-based Configure complain about
	/usr/src/linux?

	/dev/kmem-based lsof needs kernel header files from
	/usr/src/linux/... in order to know the definitions of some
	structures it reads from the kernel.  If your /usr/src/linux
	is missing or lacks the header files lsof needs, you won't
	be able to build lsof.

	Hint: if your kernel source files are in a different place,
	you may be able to use the LINUX_KERNEL environment variable
	to identify it.  Consult the 00XCONFIG file of the lsof
	distribution for more information on LINUX_KERNEL and other
	cross-configuration controls.

9.2.2	Why does /dev/kmem-based lsof complain about /dev/kmem?

	/dev/kmem-based lsof reads kernel information via /dev/kmem.
	If you get this error message:

		lsof: can't open /dev/kmem

	then the permissions on /dev/kmem or the authority you have
	when using lsof aren't powerful enough to allow lsof to
	read from it.  Often /dev/kmem is owned by the kmem or
	system group and has group read permission, so lsof needs
	to run setgid kmem or system, or the login that runs it
	must be in the kmem or system group (that's the way I test
	lsof).  So, become the super user and:

	either		$ chgrp kmem lsof
	or		$ chgrp system lsof
	and		$ chmod 2755 lsof

9.2.3	Why can't /dev/kmem-based lsof find kernel addresses?

	The failure of /dev/kmem-based lsof to read kernel addresses
	usually is accompanied by error messages like:

		lsof: can't read kernel name list from <file_name>
		lsof: missing kernel high memory definition
		lsof: missing kernel memory map definition
		lsof: missing kernel memory start definition
		lsof: no _task kernel definition
		lsof: can't read memory parameters

	These messages describe failures in obtaining addresses
	for the symbols that identify kernel structures lsof wants
	to read.  Lsof obtains kernel symbol addresses from the
	/zSystem.map or /System.map files -- one will usually be
	the <file_name> argument in the "can't read kernel name
	list from" error message.  You might not have that file,
	or it might not be in that place.  (See the following
	sections for more information.)

9.2.4	Why does /dev/kmem-based lsof have trouble reading kernel
	structures?

	Your kernel and /System.map or /zSystem.map file may not
	match.  (See the next section.)

9.2.5	Where is the system map file for kernel symbol->address
	translations for /dev/kmem-based lsof?  Why doesn't it match
	my kernel?

	/dev/kmem-based lsof uses the system map file (also called
	the  symbol->address translation file) to locate addresses
	of the symbols for kernel information it needs to read.
	Without this file, lsof cannot function.

	The system map file should be installed when you install
	a new kernel.  It is not uncommon that people make and
	install a new kernel, but forget to install its corresponding
	system map file.

	/dev/kmem-based lsof tries to determine the system map
	file's path when it runs, by looking for it in these places
	(in this order):

	    /System.map
	    /boot/System.map
	    /zSystem.map
	    /boot/zSystem.map
	    /usr/src/linux/System.map
	    /usr/src/linux/zSystem.map

	(This list is coded in the Linux dproc.c module, should
	you want to change it.)

	If you want to know what system map file lsof will use,
	specify the -h option and look at the default name (listed
	in parentheses) for the -k option.

	If lsof can't find a system map file, it issues an error
	message to that effect and quits.

	If lsof's system map file scan produces the wrong result,
	and you know where a system map file can be found that
	matches the running kernel, you can use lsof's -k option
	to defeat the scan.

9.2.5.1	What do kernel symbol address mismatch error messages mean
	for /dev/kmem-based lsof?

	/dev/kmem-based lsof has code, courtesy of Marty Leisner
	<leisner@sdsp.mc.xerox.com>, that tries to determine if
	the system map file and the booted kernel are a matched
	set.  The code compares symbol names and addresses from
	the system map file to symbol names and addresses from
	/proc/ksyms.  If any matching pair of names has different
	addresses, lsof complains and stops -- e.g.,

	    $ lsof -k ./XXX
	    lsof: kernel symbol address mismatch: do_munmap
	          /proc/ksyms value=0x122018; ./XXX value=0x12201a
	          There were 161 additional mismatches.
	          ./XXX and the booted kernel may not be a matched set.

9.2.5.2	Why does /dev/kmem-based lsof complain that query_module is
	unimplemented?

	When started, the /dev/kmem-based lsof may issue these
	messages:

	    lsof: query_module unimplemented
	    lsof: (Is CONFIG_MODULES defined in autoconf.h?)
	    lsof: unable to verify symbols in /System.map

	This fatal error occurs because the running Linux kernel
	has not been configured with kernel module support.  Lsof
	needs kernel module support to be able to verify that
	addresses in the System.map file match those of the running
	kernel.

	To solve this problem it is necessary to reconfigure and
	rebuild the Linux kernel, answering "yes" when asked if
	kernel module support should be included.  After the kernel
	has been configured and rebuilt, when installing it, don't
	forget to install its matching System.map file.

9.2.6	Why does /dev/kmem-based lsof complain about the random_fops
	and urandom_fops kernel symbols?

	When /dev/kmem-based lsof is run on the Linux 1.3.57 through
	1.3.61 kernels, it complains about address conflicts for
	two symbols, random_fops and urandom_fops with a message
	that looks like this:

	lsof: kernel symbol address mismatch: random_fops
	      get_kernel_syms() value is 0x100d76c;
	      /System.map value is 0x19abb0.
	      There was 1 additional mismatch.
	      /System.map and the booted kernel may not be a
	      matched set.
	
	Then lsof exits, because the address conflict on these
	symbols between /System.map and get_kernel_syms() output
	makes lsof believe that the /System.map file and the running
	kernel do not match.  (See the sections on /dev/kmem-based
	lsof system map file problems.)

	The address mismatch for these two symbols appears to be
	a kernel bug, triggered by using the mouse/psaux loadable
	module.  Keith Parks <emkxp01@mtcc.demon.co.uk> first
	reported the problem.  He discussed it with Ted Ts'o
	<tytso@MIT.EDU>, and Ted suggested a patch to the random.h
	header file that Keith reports seems to solve the problem.

	The patch became available at Linux release 1.3.62.  If
	you have a release below that, but above 1.3.56, you should
	look at the file Linux-mouse-module.patch in the subdirectory
	.../lsof*/dialects/linux/kmem/patches.  Keith's description
	in that file with has more detail than appears in this
	00FAQ section.

9.2.7	Why does /dev/kmem-based lsof complain about get_kernel_syms()?

	/dev/kmem-based lsof may complain:

	    lsof: get_kernel_syms() unimplemented
	    lsof: (Is CONFIG_MODULES defined in autoconf.h?)
	    lsof: unable to verify symbols in /System.map

	The fatal error described by these messages means the
	get_kernel_syms() function isn't implemented in the Linux
	kernel, probably because the kernel wasn't configured for
	module support.

	/dev/kmem-based lsof uses the information obtained from
	get_kernel_syms() to validate the information in /System.map.
	Since it is easy to install a new Linux kernel without
	installing its /System.map file, this lsof check is an
	important one.  The "unable to verify..." message indicates
	that lsof is unable to validate the /System.map symbols
	with information obtained from get_kernel_syms().

	If you look at /usr/src/linux/include/linux/autoconf.h
	you'll probably find there's no ``#define CONFIG_MODULES''
	in it.  To eliminate this error you must define CONFIG_MODULES
	in autoconf.h and rebuild the kernel.  Don't forget to
	install the System.map file from the newly built kernel.

9.2.8	Why does /dev/kmem-based lsof complain "WARNING: uncertain
	kernel loader format; assuming..."?

	Lsof may complain:

	    lsof: WARNING: uncertain kernel loader format; assuming ...

	if it was unable to determine whether the Linux kernel was
	loaded in COFF or ELF format from the information provided
	by get_kernel_syms() or query_module().  The kernel load
	format dictates whether the kernel symbols whose addresses
	lsof requires should have a leading underscore.  (COFF
	kernel symbols do.)

	When /dev/kmem-based lsof can't determine the kernel load
	format, it assumes and reports a default, established by
	the Configure script's analysis of autoconf.h -- i.e., if
	autoconf.h contains ``#defines CONFIG_KERNEL_ELF'' the
	default is ELF.  If the default kernel load format chosen
	by lsof is wrong, other kernel symbol mismatch warning
	messages can result.

	The best attempt at solution is to rebuild the kernel,
	first making sure that CONFIG_MODULES is defined in
	/usr/src/linux/include/linux/autoconf.h with a
	``#define CONFIG_MODULES'' preprocessor directive.  Don't
	forget to install the System.map file from the newly built
	kernel.

9.2.9	/dev/kmem-based lsof Problems Under Linux 2.1.x

9.2.9.1	Why does Configure say ``Testing lseek() with gcc'' for
	/dev/kmem-based lsof for Linux 2.1.x?

	Some versions of Linux 2.1.x libc have a flawed lseek()
	function that will not accept kernel addresses as seek
	offsets.  That's because the kernel addresses have their
	high order bit set to one -- i.e., appear to be negative
	-- and the lseek() function in some 2.1.x libc's mistakenly
	perceives them, when returned as a legitimate response to
	a kernel lseek() system call, to be a kernel error response.

	Later Linux 2.1.x distributions have a corrected lseek()
	function in their libc -- it will be 5.4.x, but I don't
	yet know the value of x.  Look at the __lseek.S libc source
	module and see if it has ``#define __CHECK_RETURN_ADR'' in
	it.  If it does, then your libc has H. J. Lu's lseek() fix,
	and /dev/kmem-based lsof's Configure should find that it
	works correctly.

	To determine the correct operation of lseek(), /dev/kmem-based
	lsof's Configure script runs a small test program that does
	a test seek on /dev/kmem.  If the seek fails, the test
	program's report to Configure causes it to use the source
	code for a private lseek() interface to the kernel (It's
	in .../dialects/linux/__lseek.s.) and issue the message:

	    Lseek() is suspect; using private __lseek.s.

	If /dev/kmem-based lsof reports your lseek() function is
	suspect, you should update your libc.

9.2.9.2	Why does Configure's lseek() test complain about read
	permissions for /dev/kmem-based lsof for Linux 2.1.x?

	The lseek() test program that /dev/kmem-based Configure
	runs must be able to open /dev/kmem with read permission.
	If it can't do that, it fails.  Configure then reports:

	    Configure for Linux 2.1.x needs read permission to /dev/kmem
	    in order to test lseek() on it.

	You must run the Configure script with sufficient power
	that its test program can open /dev/kmem for reading --
	e.g., run Configure while su'd to root, give /dev/kmem
	broader permissions, etc.

9.2.10	What do the /dev/kmem-based lsof WARNING messages about
	kncache.h mean?

	The dialects/linux/kmem/Mksrc shell script, called by the
	Configure shell script, builds a private lsof header file
	in dialects/linux/kmem/include called kncache.h.  It defines
	structures and constants for lsof's probing of kernel name
	caches.

	/dev/kmem-based lsof builds kncache.h by examining files
	in the Linux kernel and application source trees, including:

	    /usr/include/linux/nfs.h
	    /usr/include/linux/nfs_fs.h
	    /usr/src/linux/fs/dcache.c
	    /usr/src/linux/fs/nfs/dir.c
	    /usr/src/linux/include/linux/dcache.h

	(Mksrc doesn't examine all these files for all Linux kernels.
	See Mksrc for details.)

	Warning messages that mention kncache.h are issued when
	Mksrc's examination of these application and kernel files
	fails to yield the definitions lsof needs.

	If your Configure step yields a kncache.h diagnostic message,
	be sure the Linux kernel source tree is available to and
	can be read by the Mksrc script.  If it is, check Mksrc
	for further information or contact me via e-mail.

9.2.11	What does "WARNING: kncache.h defines no kernel name caches."
	from /dev/kmem-based lsof mean?

	If the /dev/kmem-based lsof Mksrc script can't locate any
	kernel name cache definitions for the kncache.h header
	file, when lsof executes it issues this warning message.
	The warning means that lsof will be unable to transfer any
	path name components from kernel name caches to its output
	NAME column.

	See the preceding section for information on how Mksrc
	locates kernel name cache definitions.

9.3	/proc-based Linux lsof Questions

9.3.1	Why doesn't /proc-based lsof report file offsets (positions)?

	/proc-based lsof can't report file offsets (positions) when
	no offset information is available in the /proc/<PID>/fd/
	links that describe the files open to a process.  During
	its initialization /proc-based lsof tests to see if offset
	information might be present in the st_size element of the
	stat structure returned by the lstat(2) kernel function,
	when applied to one of its own open files.

	To see if /proc-based lsof thinks your kernel reports
	reliable offset information, specify the -o option to it.
	If it replies with:

	    lsof: WARNING: can't report offset; disregarding -o.
	
	then its initialization test has indicated that using
	lstat(2) on one of its own open files in /proc/<PID>/fd
	doesn't deliver offset information.  (The /proc-based lsof
	offset test may be found in the .../dialects/linux/proc/dproc.c
	initialize() function.)

	Contact me via e-mail for information on a possible kernel
	patch that allows lstat(/proc/<PID>/fd/<FD>) to deliver
	offset (position) information.

9.3.2	Why does /proc-based lsof report "can't identify protocol" for
	some socket files?

	/proc-based lsof may report:

	    COMMAND PID ... TYPE ... NODE NAME
	    pump    226 ... sock ...  309 can't identify protocol

	This means that it can't identify the protocol (i.e., the
	AF_* designation) being used by the open socket file.  Lsof
	identifies protocols by matching the node number associated
	with the /proc/<PID>/fd entry to the node numbers found in
	selected files of the /proc/net sub-directory.  Currently
	/proc-based lsof examines these protocol files:

	    /proc/net/ax25		(untested)
	    /proc/net/ipx		(needs kernel patch)
	    /proc/net/raw
	    /proc/net/TCP
	    /proc/net/UDP
	    /proc/net/unix

	If /proc-based lsof says it can't identify the protocol
	for an open socket file, you may be able to identify the
	protocol yourself by using grep to look for the specific
	node number in the files of /proc/net -- e.g.,

	    $ grep <node_number> /proc/net/*

	You may not be able to find the desired node number, because
	not all kernel protocol modules fully support /proc/net
	information.  The AF_PACKET driver, for example, doesn't
	create a /proc/net/packet file with information about its
	open socket files.

	If you find a matching node number in a /proc/net file that
	is not currently being processed by lsof, contact me via
	email.  I'll discuss adding support to /proc-based lsof
	for the protocol with you.

	Some /proc-based lsof protocol support is incomplete without
	further work.
	
	The code that processes /proc/net/ax25 has never been tested
	on a machine with active AX25 support.

	The code that matches node numbers of open IPX protocol
	socket files to those in /proc/net/ipx requires Jonathan
	Sergent's Linux 2.1.79 patch to /usr/src/linux/net/ipx/af_ipx.c.
	The patch, suitable for input to Larry Wall's patch program,
	may be found in the lsof distribution file:

	    .../dialects/linux/proc/patches/net_ipx_af_ipx.c.patch

9.3.3	Why does /proc-based lsof warn about unsupported formats?

	Lsof may issue the following warning:

	    lsof: WARNING: unsupported format: /proc/net/<file>

	if the header line of the indicated <file> in /proc/net --
	ax25, ipx, raw, tcp, udp, or unix -- doesn't match what
	lsof expects to find.

	When the header line of a /proc/net file isn't what lsof
	expects, lsof probably can't parse the rest of the file
	correctly and doesn't try.  As a result, lsof can't report
	any NAME column information (e.g., local and remote addresses)
	for socket files bound to the indicated network protocol.

	If you get this warning, please send me e-mail.  Include
	the contents of the file lsof claims has an unsupported
	format.

9.3.4   Why does /proc-based lsof report "(deleted)" after a path name?

	The "(deleted)" notation following a path name in /proc-based
	lsof's NAME column comes from the /proc/<PID>/fd/<FD> entry
	for the open file.  It's the Linux kernel's way of indicating
	the file is open but has been unlinked (rm'd).

9.3.5	Why doesn't /proc-based lsof report full open file information
	for all processes?

	/proc-based lsof can only report on processes whose /proc
	files it has permission to read.  /proc normally grants
	permission to read all its files only to root or to the
	owning user ID.

	Without permission to read most /proc files, lsof can only
	report full information for processes belonging to the user
	who is running lsof.  /proc-based lsof may be able to report
	some information for all processes, depending on the
	permissions of their associated /proc files, but usually
	/proc-based lsof won't be able to access the files in
	/proc/<PID>/fd/ that describe regular open files.

	If you want /proc-based lsof to report on all processes, you
	must install it with setuid-root permission.

9.3.6	Why won't Customize offer to change HASDCACHE or WARNDEVACCESS
	for /proc-based lsof?

	/proc-based lsof doesn't read device information from /dev
	or the device cache file, so it makes no sense to change
	the state of device cache processing or /dev node accessibility
	warnings.

9.4	What about lsof, Linux, and the Alpha or SPARC processors?

	Some versions of lsof, /dev/kmem-based and /proc-based,
	may work under some versions of Linux on the Alpha or SPARC
	processors.  There are some Alpha and SPARC pre-processor
	tests that change sections of lsof code, but they aren't
	tested often, since I don't have regular access to these
	architectures.  (The folks at Red Hat test more regularly
	than I do.)

	Try lsof on your Alpha or SPARC system; it may work for
	you.  If it doesn't, feel free to discuss it with me via
	e-mail.


10.0	NetBSD Problems

10.1	Why doesn't lsof report on open kernfs files?

	Lsof doesn't report on open NetBSD kernfs files because the
	structures lsof needs aren't defined in the kernfs.h header
	file in /sys/misc/kernfs.


11.0	NEXTSTEP and OpenStep Problems

11.1	Why can't lsof report on 3.1 lockf() or fcntl(F_SETLK)
	locks?

	Lsof has code to test for locks defined with lockf() or
	fcntl(F_SETLK) under NEXTSTEP 3.1, but that code has never
	been tested.  I couldn't test it, because my NEXTSTEP 3.1
	lockf() and fcntl(F_SETLK) functions return "Invalid
	argument" every way I have tried to invoke them.

	If your NEXTSTEP 3.1 system does allow you to use lockf()
	and fcntl(F_SETLK) and lsof doesn't report locks set with
	them, then the code in .../dialects/next/dnode.c probably
	isn't correct.  Please contact me via email and tell me
	how you got your lockf() and fcntl(F_SETLK) system calls
	to work.

11.2	Why doesn't lsof compile for NEXTSTEP with AFS?

	I no longer have a NEXTSTEP test system that has AFS.
	Changes to lsof since I once had a test system have caused
	me to change the AFS code in NEXTSTEP without being able
	to test the changes.

	If you need AFS support for NEXTSTEP and can't get it to
	compile, please contact me.  Perhaps we can jointly fix
	the problems.


12.0	OpenBSD Problems

12.1	Why doesn't lsof support kernfs on my OpenBSD system?

	Lsof supports the kernel file system on OpenBSD versions
	whose /sys/miscfs/kernfs/kernfs.h (or <miscfs/kernfs/kernfs.h>
	header file correctly defines the kern_target structure.
	The lsof Configure script's openbsd stanza checks for the
	presence of the structure's kt_name element and activates
	kernfs support for the CFLAGS -DHASKERNFS definition only
	when it finds kt_name.

	The kernfs.h header file is scheduled to be updated in the
	OpenBSD 2.1 release, according to Kenneth Stailey
	<kstailey@disclosure.com>, who authored its changes.

12.2	Will lsof work on OpenBSD on non-Intel-based architectures?

	I've not tested lsof on an OpenBSD system that uses a
	non-Intel-based architecture, but I've had one report that
	lsof 4.33 compiles and works on OpenBSD for the pmax
	architecture (decstation 3100).

12.3	<sys/pipe.h> problems

12.3.1	Why does the compiler claim nbpg isn't defined?

	When compiling lsof on some (older) OpenBSD SPARC versions,
	the compiler may complain:

	    In file included from ../dlsof.h:191,
                 from ../lsof.h:166,
                 from fino.c:52:
	    /usr/include/sys/pipe.h:83: `nbpg' undeclared here
					(not in a function)
	    /usr/include/sys/pipe.h:83: size of array `ms' has
					non-integer type

	This happens because <sys/pipe.h> uses NBPG from
	<machine/param.h> to size the `ms' array, and some OpenBSD
	systems define NBPG in terms of a kernel integer variable,
	nbpg.

	Lsof revisions 4.46 and above have a hack to dlsof.h,
	developed by Volker Borchert <bt@teknon.de> that avoids
	the compiler problem for SPARC OpenBSD 2.3.  The hack might
	work for other OpenBSD SPARC versions, but hasn't been
	tested there.
	
	If you want to enable the hack for your OpenBSD SPARC
	version, modify this code in .../dialects/n+obsd/dlsof.h:

	    # if    defined(OPENBSDV)
	    #  if   OPENBSDV==2030 && defined(__sparc__)
	    #   if  defined(nbpg)
	    #undef  nbpg
	    #   endif       /* defined(nbpg) */
	    #define nbpg    4096            /* WARNING!!!  ... */
	    #  endif        /* OPENBSDV==2030 && defined(__sparc__) */
	    #include <sys/pipe.h>
	    #endif  /* defined(OPENBSDV) */

	You will probably want to change the second #if test to
	match your OpenBSD version.  You may also want to change
	what value is assigned to nbpg.  See the next section,
	"What value should I assign to nbpg?"

12.3.2	What value should I assign to nbpg?

	If you need to enable the nbpg hack, described in "Why does
	the compiler claim nbpg isn't defined?", you may also need
	to assign a value other than 4096 to nbpg.  4096 works for
	the sun4c processor and should work for sun4m, but 8192
	may be needed for sun4.

	Check <machine/param.h> and other OpenBSD documentation to
	determine the correct nbpg assignment.


13.0	Output Problems

13.1	Why do the lsof column sizes change?

	Lsof dynamically sizes its output columns each time it runs
	to make sure that each column takes the minimum space.
	Column parsing -- e.g., with awk -- is possible, because
	each column is guaranteed to be separated from the preceding
	one by at lease one space, and no column except the last
	(NAME) contains embedded spaces.

13.2	Why does the offset have ``0t' and ``0x'' prefixes?

	The offset value that appears in the SIZE/OFF column has
	``0t' and ``0x'' prefixes to distinguish it from size values
	that may appear in the same column.

	Normally if the offset value is less than 100,000,000 (8
	digits), it appears in decimal with a ``0t' prefix; over
	99,999,999, in hexadecimal with a ``0x'' prefix.

	A decimal offset is handy, for example, when tracking the
	progress of an outbound ftp transfer.  When lsof reports
	on the ftp process, it will report the size of the file
	being sent with its open descriptor; it will report the
	progress of the transfer via the offset of the outbound
	open ftp data socket descriptor.

	The ``-o [n]'' option may be used to specify the maximum
	number of decimal digits to be printed after ``0t'' before
	lsof switches to the hexadecimal digits after `0x''.  As
	already noted, the default decimal digit count is 8.

13.3	What are the values printed in the FILE_FLAG column
	and why is 0x<value> sometimes included?

	The two comma separated lists, separated by a semicolon,
	printed in the FILE-FLAG column (when the "+fg" option is
	specified), are short-hand names or hexadecimal values for
	the bits lsof finds in the f_flag or f_flags member of file
	structures for files (the first list, the one before the
	semicolon), and process open files flags found in various
	kernel structures, often named "pofile" (the second list,
	the one after the semicolon).

	Lsof determines the short-hand names from symbols in the
	<fcntl.h>, <linux/fs.h>, <sys/fcntl.h>, <sys/fcntlcom.h>,
	o<sys/file.h>, and <sys/user.h> header files.

	See the discussion of FILE-FLAG in the OUTPUT section of
	the lsof man page, and the FF_* and POF_* symbols in lsof.h
	for a list of the names.

	Bits with no names defined for them are represented by an
	0x<value> member of the comma-separated list -- a hexadecimal
	integer.  When "+fG" is specified (instead of "+fg"), lsof
	will list all flag values as two hexadecimal integers,
	separated by a semicolon.

13.3.1	Why doesn't lsof display FILE_FLAG values for my dialect?

	All versions of lsof except the /proc-based Linux lsof
	report FILE-FLAG values.  Lsof can't obtain FILE-FLAG
	information from the Linux /proc interface.

13.4	Network Addresses

13.4.1	Why does lsof's -n option cause IPv4 addresses, mapped to
	IPv6, to be displayed in IPv6 notation?

	When you use the -n option to tell lsof to display numeric
	network addresses, and an IPv4 address has been mapped to
	IPv6, lsof displays the address in IPv6 format and puts
	"ipv4" in the TYPE column.  That combination indicates the
	IPv4 address has been mapped to IPv6.

	For example, the IPv4 address 1.2.3.4, when mapped to an
	IPv6 address, will be displayed by lsof as:

	    [::ffff:1.2.3.4]
	
	The enclosing brackets are lsof's signal that this is an
	IPv6 address.  Inside the brackets is a standard IPv6
	address, reported by inet_ntop().  The first two colons,
	signifying zeroes in the first 64 bits of the IPv6 address,
	and the hexadecimal ffff in the next 32 bits, indicate that
	the last 32 bits contains a mapped IPv4 address, which is
	then displayed in IPv4 dot notation.

14.0	Pyramid Version Problems

14.1	DC/OSx Problems

14.2	Reliant UNIX Problems

14.2.1	Why does lsof complain that it can't find /stand/unix?

	When you attempt to run lsof on a Reliant UNIX multi-
	processor, it may complain that it can't find the kernel
	boot file, /stand/unix.  That's because normally the
	/stand/unix file is only located on one node's root file
	system.  Lsof needs the file to obtain kernel data addresses.

	The work-around is to copy /stand/unix to each node.

14.2.2	Why does lsof complain about bad kernel addresses?

	Lsof may complain that some Reliant UNIX kernel addresses
	aren't usable -- e.g., it may issue a warning like this:

	    lsof: WARNING: can't read kernel's name cache: 0x00000000

	This is usually the result  of having a /stand/unix file
	on a Reliant multi-processor that isn't the booted kernel
	file.  Because it doesn't have symbol addresses that match
	those of the running kernel, lsof has problems reading
	kernel values.

	One work-around is to copy the correct boot file to
	/stand/unix.  If the booted kernel file is available under
	another name -- e.g., /stand/unix.myboot -- another
	work-around is to use lsof's -k flag to specify the alternate
	name as the source of kernel name list values:

	    $ lsof -k /stand/unix.myboot ...

14.2.3	Why does the Reliant C compiler give so many warning messages
	when compiling lsof?

	The Reliant Unix Pyramid C compiler issues warning messages
	that I haven't found a convenient way to suppress.  You
	can ignore warning messages about casts and conversions
	that lose bits.  The message "warning: undefining __STDC__"
	is intentionally caused by the lsof MkKernOpts configuration
	script to suppress warning messages about cast and conversion
	problems in standard system header files, such as <stdio.h>
	and <string.h>.

14.2.4	Why does the lsof compilation require -Klp64 for Reliant UNIX
	5.44 and why does my compiler reject it?

	The -Klp64 flag enables the 64 bit data model lsof requires
	for handling Reliant Unix 5.44 and above 64 bit kernel
	pointers.  Some compilers don't support -Klp64.

	If lsof's Configure script detects that -Kl64 is required,
	it test-compiles a null program to see if the compiler
	supports -Klp64.  If the compiler doesn't support -Klp64,
	Configure echoes this message and quits:

	    /usr/ccs/bin/cc doesn't support -Klp64.  Consult 00FAQ.

	You can't proceed until you have a compiler that supports
	-Klp64.  Hint: if you have a compiler that does support
	it, but the compiler is located at a path other than
	/usr/ccs/bin/cc, supply its path to Configure via the
	LSOF_CC environment variable -- e.g., if the compiler that
	supports -Klp64 is in /opt/C/bin/cc, you might use this
	Configure command:

	    $ LSOF_CC=/opt/C/bin/cc Configure pyramid

	I have used both these compilers successfully on Reliant
	Unix 5.44 and above:

	    Pyramid C Compiler 06.0A00

	    CDS++ Version 02.A00

	Compilers known to lack support for -Klp64 include C-DS-MI
	V1.2 and gcc.


15.0	SCO Problems

15.1	SCO OpenServer Problems

15.1.1	How can I avoid segmentation faults when compiling lsof?

	If you have an older SCO OpenServer compiler, it may get
	a segmentation fault when compiling some lsof modules.
	That appears to happen because of the -Ox optimization
	action requested in the lsof Makefile.

	Try changing -Ox to -O in the DEBUG string of the Makefile
	that Configure generates for you -- e.g., change

		DEBUG=  -Ox
	to
		DEBUG=  -O

	Bela Lubkin <belal@sco.COM> supplied this tip and Steve
	Williams <stevew@innotts.co.uk> verified it.

15.1.2	Where is libsocket.a?

	If you compile lsof and the loader says it can't find the
	socket library, libsocket.a, called by the -lsocket option
	in the lsof compile flags, you probably are running an SCO
	OpenServer release earlier than 5.0 and don't have the
	TCP/IP Development System package installed.

	You may have the necessary header files, because you have
	the TCP/IP run-time package installed, but if you don't
	have the TCP/IP Development System package installed, you
	won't have libsocket.a.

	Your choices are to install the TCP/IP Development System
	package or upgrade to OpenServer Release 5.0.  You will
	find libsocket.a in 5.0 -- you'll find all the libraries
	and header files there, in fact -- and you can use gcc to
	compile lsof if you don't want to install the 5.0 Development
	System package.

15.1.3	Why do I get "warning C4200" messages when I compile lsof?

	When you compile lsof under OSR 3.2v4.2 (and perhaps under
	earlier versions as well), you may get many compiler warning
	messages of the form:

	    node.c(183) : warning C4200: previous declarator is not
	    compatible with default argument promotion

	In my opinion this is a bug in the OSR compiler.  Because
	the compiler cannot handle full ANSI-C prototypes, it
	assumes default types for function parameters as it encounters
	untyped in a function prototype -- e.g., in this function
	declaration from node.c,

	    readrnode(ra, r)
		KA_T ra;
		struct rnode *r;
	    {
	    ...
	
	the compiler assigns default int types to the ra and r
	arguments.

	Then, when the compiler encounters the fully typed parameters
	after the function skeleton and sees parameters with types
	that don't match the assumptions it previously made, it
	whines about its own assumptions.

	You can ignore these messages.

15.2	SCO UnixWare Problems


16.0	Sun Problems

16.1	My Sun gcc-compiled lsof doesn't work -- why?

	Gcc can be used to build lsof successfully.  However, an
	improperly installed Sun gcc compiler will usually not
	produce a working lsof.

	Under SunOS 4.1.x this may happen when the gcc compiler is
	copied from one Sun architecture -- e.g., from a sun4m to
	a sun4.  The problem comes from the copying of the special
	#include header files that gcc "fixes" during installation
	to circumvent ANSI-C conflicts, especially on #else and
	#endif pre-processor declarations.  Some of the "fixed"
	header files declare kernel structures whose length varies
	with architecture type.  In particular, the size of the
	user structure (<sys/user.h>) changes with architecture
	type, and, since lsof gets command name and file pointers
	from that structure, can cause lsof to malfunction when
	its length is incorrect.

	While the "fixing" of header files is eliminated at gcc
	2.8 and above, architecture-specific header files may still
	remain in the SunOS gcc private include tree.  In particular,
	gcc's private machine/ include subdirectory may still exist
	and may point to a specific architecture's private header
	files in the same tree -- e.g., machine -> sun4c/.  If your
	machine/ points to an architecture type different from the
	output of `uname -m`, try the temporary work-around described
	in the "How can I make lsof compile with gcc under SunOS
	4.1.x?" section.

	These architecture-related structure differences generally
	do not occur under Solaris 2.x, 7, 8 BETA, and 8 BETA-Refresh.
	Instead, the more common reason a gcc-compiled lsof doesn't
	work there is that the special gcc header files were not
	updated during the change from one version Solaris to the
	next -- e.g., from 2.4 to 2.5.

	If your Sun gcc-compiled lsof doesn't report anything, or
	reports ``can't read proc table,'' check that the gcc
	fixincludes or fixinc.svr4 (Solaris 2.x, 7, 8 BETA, and 8
	BETA-Refresh) step was run on the system where you're using
	gcc to compile lsof.  As an alternative, if you have the
	SunPro C compiler available, use it to compile lsof --
	e.g., use the solariscc or sunoscc Configure abbreviations.

16.2	How can I make lsof compile with gcc under Solaris 2.[456],
	2.5.1, or 7?

	Presuming your gcc-specific header files are wrong for
	Solaris, edit the lsof Configure-generated Makefile and
	lib/Makefile and make this change:

		CFGF=   -Dsolaris=20400 ...
	to
		CFGF=   -Dsolaris=20400 -D__STDC__=0 -I/usr/include ...

	or change:

		CFGF=   -Dsolaris=20500 ...
	to
		CFGF=   -Dsolaris=20500 -D__STDC__=0 -I/usr/include ...

	or change:

		CFGF=   -Dsolaris=20501 ...
	to
		CFGF=   -Dsolaris=20501 -D__STDC__=0 -I/usr/include ...

	This is only a temporary work-around.  You really should
	rerun gcc's fixinc.svr4 script to update your gcc-specific
	header files or install gcc 2.8.0, which has no need for
	private copies of Solaris include files.

16.3	How can I make lsof compile with gcc under SunOS 4.1.x?

	Presuming your gcc-specific header files are wrong for
	SunOS 4.1.x, edit the lsof Configure-generated Makefile
	and lib/Makefile and change:

		CFGF=   -ansi -DSUNOSV=40103 ...
	to
		CFGF=   -DSUNOSV=40103 -I/usr/include ...

	This is only a temporary work-around.  You really should
	rerun gcc's fixincludes script to update your gcc-specific
	header files or install gcc 2.8, which uses fewer private
	include files.  (But see the caution in the "My Sun
	gcc-compiled lsof doesn't work -- why?" section about
	remaining architecture specific SunOS header files that
	gcc 2.8 will still have in its private include directory.)

16.4	Why does Solaris Sun C complain about system header files?

	You're probably trying to use /usr/ucb/cc if you get compiler
	complaints like:

	    cc -O -Dsun -Dsolaris=20300 ...
	    "/usr/include/sys/machsig.h", line 81: macro BUS_OBJERR
	    redefines previous macro at "/usr/ucbinclude/sys/signal.h",
	    line 444

	Note the reference to "/usr/ucbinclude/sys/signal.h".  It
	reveals that the BSD Compatibility Package C compiler is
	in use.  Lsof requires the ANSI C version of the Solaris
	C compiler, usually found in /usr/opt/bin/cc or
	/opt/SUNWspro/bin/cc.

	Try adding a CC string to the lsof Makefile that points to
	the Sun ANSI C version of the Sun C compiler -- e.g.,

	    CC= /usr/opt/bin/cc
	or
	    CC= /opt/SUNWspro/bin/cc.

16.5	Why doesn't lsof work under my Solaris 2.4 system?

	If lsof doesn't work under your Solaris 2.4 system -- e.g.,
	it produces no output, little output, or the output is
	missing command names or file descriptors -- you may have
	a pair of conflicting Sun patches installed.

	Solaris patch 101945-32 installs a kernel that was built
	with a <sys/auxv.h> header file whose NUM_*_VECTORS
	definitions don't match the ones in the <sys/auxv.h> updated
	by Solaris patch 102303-02.

	NUM_*_VECTORS in the kernel of patch 101945-32 are smaller
	than the ones in the <sys/auxv.h> of patch 102303-02.  The
	consequence is that when lsof is compiled with the <sys/auxv.h>
	whose NUM_*_VECTORS definitions are larger than the ones
	used to compile the patched kernel, lsof's user structure
	does not align with the one that the kernel employs.

	If you have these two patches installed, contact Sun and
	complain about the mis-match.

	The lsof Configure script attempts to work around the
	mis-matched patches by including a modified <sys/auxv.h>
	header file from ./dialects/sun/include/sys.  That auxv.h
	has these alternate definitions:

		    #define NUM_GEN_VECTORS 4
		    #define NUM_SUN_VECTORS 8
	
	The Configure script issues a prominent WARNING that it is
	putting this work-around into effect.  If it doesn't succeed
	for you, please contact me.

	I thank Leif Hedstrom <leif@infoseek.com> for identifying the
	offending patches.

16.6	Where are the Solaris header files?

	If you try to compile lsof under Solaris and get a compiler
	complaint that it can't find system header files, perhaps
	you forgot to add the header file package, SUNWhea.

16.7	Where is the Solaris /usr/src/uts/<architecture>/sys/machparam.h?

	When you try to Configure lsof for Solaris 2.[23456], 2.5.1,
	and 7 -- e.g., on a `uname -m` == sun4m system -- Configure
	complains:

	    grep: /usr/src/uts/sun4m/sys/machparam.h:
			No such file or directory
	    grep: /usr/src/uts/sun4m/sys/machparam.h:
			No such file or directory

	And when you try to compile the configured lsof, cc or gcc
	complains:

	    dproc.c:530: `KERNELBASE' undeclared (first use this function)

	The explanation is that somehow your Solaris system doesn't
	have the header files in /usr/src/uts it should have.  Perhaps
	someone removed the directory to save space.  Perhaps you're
	using a gcc installation, copied from another system.  In any
	event, you will have to load the header files from the SUNWhea
	package of your Solaris distribution.

	KERNELBASE is an important symbol to lsof -- it keeps lsof
	from sending an illegal kernel value to kvm_read() where
	a segmentation violation might result (a bug in the kvm
	library).  Lsof can get illegal kernel values because it
	reads kernel values slowly with kvm_read() calls that the
	kernel is changing rapidly.

	Lsof doesn't need KERNELBASE at Solaris 2.5 and above,
	because it has a Kernelbase value whose address lsof can
	find with /dev/ksyms and whose value it can read with
	kvm_read().  Under Solaris 2.5 /usr/src/uts has moved to
	/usr/platform.

16.8	Why does Solaris lsof say ``can't read proc table''?

	When lsof collects data on processes, using the kvm_*()
	functions to scan the kernel's proc structure table, it
	checks to make sure it has identified a reasonable number
	of them -- a minimum of three.  When lsof can't identify
	three processes during a scan, it repeats the scan.

	When five scans fail to yield three processes, lsof issues
	the fatal message:

		lsof: can't read proc table

	and exits.

	Usually lsof fails to identify three processes during a
	scan because its idea of the form of the proc structure
	differs from that being used by the kernel.  Since the proc
	structure is defined in <sys/proc.h> and other /usr/include
	header files, the root cause of a proc structure discrepancy
	usually can be found in the composition of /usr/include.

	One common way that /usr/include header files can be
	incorrect is that gcc was used to compile lsof, gcc used
	its special (i.e., "fixed") header files instead of the
	ones in /usr/include, and the special gcc header files
	weren't updated when Solaris was.  Answers to these questions:

	    My Sun gcc-compiled lsof doesn't work -- why?

	    How can I make lsof compile with gcc under Solaris 2.[456],
	    2.5.1, or 7?

	    How can I make lsof compile with gcc under SunOS 4.1.x?

	    Why does Solaris Sun C complain about system header files?

	discuss the gcc header file problem and offer suggestions
	on how to fix it or work around it.

	It may also be that you are trying to run a version of lsof
	that was compiled on an older version of Solaris.  For
	example, an lsof executable, compiled for Solaris 2.4, will
	produce the ``can't read proc table'' message if you try
	to run it under Solaris 2.5.  If you have compiled lsof
	under Solaris 2.5 and it still won't work, see if the header
	files in /usr/include have been updated to 2.5, or still
	represent a previous version of Solaris.

	Another source of header file discrepancies to consider is
	the Solaris patch level and whether a binary kernel patch
	was not matched with a corresponding header file update.
	See the "Why doesn't lsof work under my Solaris 2.4 system?"
	question for an example of one in Solaris 2.4 -- there may
	be other such patch conflicts I don't know about.

16.9    Why does Solaris lsof complain about a bad cached clone device?

	When lsof revisions below 4.04 have been run on a Solaris
	system and have been allowed to create a device cache file,
	the running of revisions 4.04 and above on the same systems
	may produce this complaint:

	    lsof: bad cached clone device: ...
	    lsof: WARNING: created device cache file: ...

	This is the result of a change in the device cache file
	that took place at lsof revision 4.04.  The change introduced
	a node number into the clone device lines of the device
	cache file and was done in such a way that lsof could detect
	device cache files whose clone lines don't have node numbers
	(lines created by previous lsof revisions) and recognize
	the need to regenerate the device cache file.

16.10	Why doesn't Solaris make generate .o files?

	Solaris /usr/ccs/bin/make won't generate .o files from .c
	files if /usr/share/lib/make/make.rules is missing.  It
	may be found in and installed from the SUNWsport package.

16.11	Why does lsof report some Solaris 2.3 and 2.4 lock types as `N'?

	For Solaris 2.3 with patch P101318 installed at level 45
	or above, and for all versions of Solaris 2.4, NFS locks
	are represented by a NFS-specific kernel lock structure
	that sometimes lacks a read or write lock type indicator.
	When lsof encounters such a lock structure, it reports the
	lock type as `N'.

16.12	Why does lsof Configure say "WARNING: no cc in ..."?

	When lsof's Configure script is executed with the solariscc
	abbreviation it tries to make sure it's using the Sun C
	compiler and not the UCB substitute from /usr/ucb/cc.
	Thus, it looks for cc in the "standard" Sun compiler
	location, /opt/SUNWspro/bin.

	If Configure can't find cc there, it issues the warning:

	    lsof: WARNING: no cc in /opt/SUNWspro/bin;
		  using cc without path.

	and uses cc for the compiler name, letting the shell find
	cc with its PATH environment variable.

	You can tell Configure where to find your cc with the
	SOLARIS_CCDIR cross-configuration environment variable.
	(See 00XCONFIG for more information on SOLARIS_CCDIR).
	For example, use this Configure shell command:

	    SOLARIS_CCDIR=/usr/special/bin Configure -n solariscc

	(SOLARIS_CCDIR should be the full path to the directory
	containing your cc.)

16.13	Solaris 7 and 8 Problems

16.13.1 Why does lsof say the compiler isn't adequate for Solaris
	7 or 8?

	Solaris 7 and 8 kernels come in two flavors, 32 and 64 bit.
	64 bit kernels run on machines that support the SPARC v9
	instruction set architecture.  Separate executables for
	some programs, -- e.g., ones using libkvm like lsof -- must
	be built for 32 and 64 bit kernels.

	Previous Sun (e.g., SC4.0) and gcc (e.g., 2.8.0) compilers
	will build lsof for 32 bit kernels, but they won't build
	it for 64 bit kernels.  The only compilers that will
	currently (October 1999) build lsof for 64 bit Solaris 7
	and 8 kernels are the Sun WorkShop Compilers C 5.0 and an
	apropriately built gcc 2.95.  (See the "How do I build a
	gcc that will produce 64 bit Solaris 7 and 8 executables?"
	section for tips on building an appropriate gcc.)

	When given the ``-xarch=v9'' flag, the C 5.0 compiler and
	associated loader and 64 bit libraries will build a 64 bit
	lsof executable; when given the "-mcpu=v9" flag, an
	appropriately built gcc 2.95 and above will build a 64 bit
	lsof executable.

	When the lsof Configure script detects a 64 bit kernel is
	in use (e.g., by executing `/bin/isainfo -kv`), and when
	it finds that the specified compiler is inappropriate,
	it complains with these messages:

	For gcc:

	    "!!!WARNING!!!=========!!!WARNING!!!=========!!!WARNING!!!"
	    "!                                                       !"
	    "! LSOF NEEDS TO BE CONFIGURED FOR A 64 BIT KERNEL, BUT  !"
	    "! THIS GCC DOESN'T SUPPORT THE BUILDING OF 64 BIT       !"
	    "! SOLARIS EXECUTABLES.  LSOF WILL BE CONFIGURED FOR A   !"
	    "! 32 BIT echo KERNEL.                                   !"
	    "!                                                       !"
	    "!!!WARNING!!!=========!!!WARNING!!!=========!!!WARNING!!!"
	
	For Sun C:

	  !!!WARNING!!!==========!!!WARNING!!!==========!!!WARNING!!!
	  !                                                         !
	  ! LSOF NEEDS TO BE CONFIGURED FOR A 64 BIT KERNEL, BUT    |
	  ! THE VERSION OF SUN C AVAILABLE DOESN'T SUPPORT THE      !
	  ! -xarch=v9 FLAG.  LSOF WILL BE CONFIGURED FOR A 32 BIT   !
	  ! KERNEL.                                                 !
	  !                                                         !
	  !!!WARNING!!!==========!!!WARNING!!!==========!!!WARNING!!!

16.13.2	Why does Solaris 7 or 8 lsof say "FATAL: lsof was compiled
	for..."?

	Solaris 7 or 8 lsof may say:

	    lsof: FATAL: lsof was compiled for a xx bit kernel,
		  but this machine has booted a yy bit kernel.
	
	    Where: xx = 32 or 64
		   yy = 64 or 32
	
	    (xx and yy won't match.)
	
	This message indicates that lsof was compiled for one size
	kernel and is being asked to execute on a different size
	one.  That's not possible for programs like lsof that use
	libkvm.

	Depending on the instruction sets for which you need Solaris
	7 or 8 lsof, you may need two or more versions of lsof,
	compiled for each kernel size, installed for use with
	/usr/lib/isaexec.  See the "How do I install lsof for
	Solaris 7 or 8?" section of this document for more information
	on that.

16.13.3	How do I build lsof for a 64 bit Solaris kernel under a 32
	bit Solaris kernel?

	If your Solaris system has an appropriate compiler (WorkShop
	Compilers C 5.0) and the 64 bit libraries have been installed,
	you can force lsof's Configure script to build a 64 bit
	version of lsof with:

	    $ SOLARIS_KERNBITS=64 Configure -n solariscc
	
	The SOLARIS_KERNBITS environment variable is part of the
	lsof cross-configuration support, described in the 00XCONFIG
	file of the lsof distribution.

16.13.4	How do I install lsof for Solaris 7 or 8?

	If you are installing lsof where it will be used only under
	the bit size kernel for which it was built, no special
	installation is required.

	If, however, you are installing different versions of lsof
	for different bit sizes -- e.g., for use on a 64 bit NFS
	server and from its 32 bit clients -- you should read the
	man page for isaexec(3C) and install lsof according to its
	instructions.

	The executable at the directory where lsof is to be found
	should be a hard link to /usr/lib/isaexec or a copy of it.
	In the directory there must be instruction architecture
	subdirectories -- e.g., .../sparc/ and .../sparcv9/.  The
	lsof for 64 bit size kernels is installed in the .../sparcv9/
	subdirectory; the one for 32 bit size kernels, in .../sparc/.

	For example, if you're installing 32 and 64 bit lsof
	executables in /usr/local/etc, you would:

		# cd /usr/local/etc
		# ln /usr/lib/isaexec lsof
		# mkdir sparc sparcv9
		# install the 32 bit lsof as sparc/lsof
		# install the 64 bit lsof as sparcv9/lsof
		# chmod, chown, and chgrp sparc/lsof and
		  sparcv9/lsof appropriately

	Lsof permissions and ownerships are the same whether one
	or more lsof executables are being installed, with or
	without the /usr/lib/isaexec hard link.

16.13.5	Why does my Solaris 7 or 8 system say it cannot execute lsof?

	When you attempt to execute lsof, your Solaris 7 or 8 shell
	may complain:

	    ksh: ./lsof: cannot execute

	If the lsof executable exists and has the proper execution
	permissions, this error may be the result of trying to
	execute an lsof, built for a 64 bit kernel, on a 32 bit
	kernel.

	This will tell you about the lsof executable:

	    $ file lsof
	    lsof: ELF 64-bit MSB executable SPARCV9 Version 1,
		  dynamically linked, not stripped
	
	The "64-bit" notation indicates the binary was built for
	a 64 bit kernel.  To see the running kernel bit size, use
	this command:

	    $ isainfo -kv
	    32-bit sparc kernel modules

	The "32-bit" notation indicates a 32 bit kernel has been
	booted.

	The only work-around is to obtain, or Configure and make,
	an lsof for the appropriate kernel bit size.  If you
	Configure and make lsof on the kernel where you wish to
	run it the proper compiler, the lsof Configure step will
	generate Makefiles that can be used with make to build an
	appropriate lsof executable.

	To compile a 64 bit lsof, you must have a Sun compiler that
	supports the -xarch-sparcv9 option -- i.e., WorkShop
	Compilers C 5.0 or higher.

16.13.6	How do I build a gcc that will produce 64 bit Solaris 7 and
	8 executables?

	First, you need the Sun Workshop 5.0 or above C compiler.

	Next, obtain gcc 2.95 or higher from:

	    pub/egcs/snapshots/1999-07-18/egcs-core-19990718.tar.gz
	at:
	    ftp://egcs.cygnus.com

	(Unless you get the "core" distribution, you may end up
	trying to build other language products that this recipe
	won't build.)

	Before configuring gcc 2.95, put this in the shell's
	environment with the command (set, export) appropriate to
	your shell:

	    CC="cc -xarch=v9 -Wa,-xregsym=no"

	Then configure gcc via its configure script with:

	    $ configure --host=sparcv9-sun-solaris2.7 \
	    --target=sparcv9-sun-solaris2.7 ...

	(If building for Solaris 8, substitute "solaris2.8" for
	"solaris2.7".)

	Then build with make.

	    $ make

	Since I'm not a gcc construction guru, if you have trouble
	with this recipe, consult gcc experts for help.

16.14	Solaris and COMMON

16.14.1	What does COMMON mean in the NAME column for a Solaris VCHR
	file?

	When lsof puts COMMON or (COMMON) in the NAME column of a
	Solaris VCHR file, it means that the file is handled by
	the special file system functions of the kernel through a
	common vnode.

16.14.2	Why does a COMMON Solaris VCHR file sometimes seem to have an
	incorrect minor device number?

	When lsof reports on an open file in a Solaris special file
	system that uses a COMMON vnode, and the file is a VCHR
	file, lsof tries to locate the associated device node by
	looking for matches on the major and minor device numbers
	first.

	If no major and minor match results, lsof then looks for
	a match on pseudo and clone device files.  (See /devices/pseudo.)
	Those device nodes are matched specially by either their
	major or minor device numbers, but not both.  Hence, when
	lsof finds a match under those special conditions, it may
	report a value in its output DEVICE column that differs
	from one of the major and minor numbers of the device node.

	Here's an example from a sun4m Solaris 7 system:

	    $ ls -li /devices/pseudo/pm@0:pm
	    151261 crw-rw-rw-   1 root     sys      117,  0 ...
	    $ lsof /devices/pseudo/pm@0:pm
	    COMMAND ... DEVICE ...   NODE NAME
	    powerd       117,1 ... 151261 /devices/pseudo/pm@0:pm (COMMON)
	    Xsun    ...  117,0 ... 151261 /devices/pseudo/pm@0:pm

	Note that the DEVICE value for the file with (COMMON) in
	its name field has a different minor device number (1) from
	what ls reports (0), while the DEVICE value for the file
	without (COMMON) matches the ls output exactly.  Both match
	on the major device number, 117.  The minor device number
	mis-match is a result of the way the Solaris kernel handles
	special file system common vnodes, and it's the reason lsof
	puts (COMMON) after the name to signal that a mis-match is
	possible.

16.15	Why don't lsof and Solaris pfiles reports always match?

	/usr/proc/bin/pfiles for Solaris 2.6, 7, 8 BETA, and 8
	BETA-Refresh also reports information on open files for
	processes.  Sometimes the information it reports differs
	from what lsof reports.

	There are several reasons why this might be true.  First,
	because pfiles is a Sun product, based on Sun kernel
	features, its developers have a better chance of knowing
	exactly how open file information is organized.  I sometimes
	have to guess at how kernel file structure linkages are
	constructed by gleaning hints from header files.

	Second, lsof is aimed at providing information, specifically
	device and node numbers, that can be used to identify named
	file system objects -- i.e., path names.  Thus, lsof tries
	to make sure its device and node numbers match those reported
	by stat(2).  Pfiles doesn't always report numbers that
	match stat(2) -- e.g., for files using clone and pseudo
	devices via common vnodes like the nlist() /dev/ksyms usage.

	Here's the Solaris 7 COMMON VCHR example again with additional
	pfiles output:

	    $ ls -li /devices/pseudo/pm@0:pm
	    151261 crw-rw-rw-   1 root     sys      117,  0 ...
	    $ lsof /devices/pseudo/pm@0:pm
	    vic1: 10 = lsof /dev/pm
	    COMMAND ... DEVICE ...   NODE NAME
	    powerd  ...  117,1 ... 151261 /devices/pseudo/pm@0:pm (COMMON)
	    Xsun    ...  117,0 ... 151261 /devices/pseudo/pm@0:pm
	    $ pfiles ...
	    0: S_IFCHR ... dev:32,24 ino:61945 ... rdev:117,1
	    ...
	    14: S_IFCHR ... dev:32,24 ino:151261 ... rdev:117,0

	Note that the NODE number, reported by lsof, matches what
	ls(1) and stat(2) report, while the ino value pfiles reports
	doesn't.   Lsof also indicates with the (COMMON) notation
	that the DEVICE number is a pseudo one, derived from the
	character device's value.  The lsof DEVICE value matches
	the pfiles rdev value, correct behavior for a character
	device, but pfiles gives no sign that it's not possible to
	find that character device number in /devices with ls(1)
	or stat(2).

16.16	Why doesn't lsof report node number and name for some
	SunOS 4.1.4 Auspex processes?

	Some Auspex processes have files open for which lsof doesn't
	report a node number or a name.  There is no more information
	in the kernel node structure chains for these files that
	would allow lsof to supply the missing items.

	I suspect these files are using a clone of the master device
	/dev/ipc.  It's device number is (37,80).  The major of 37
	indicates a clone master and the minor of 80 is reflected
	as the major number of the Auspex files lsof can't fully
	describe.  However, the Auspex files don't have a stream
	initialized, so lsof can't connect them to the /dev/ipc
	clone master.


17.0	Lsof Features

17.1	Why doesn't lsof doesn't report on /proc entries on my
	system?

	/proc file system support is generally available only for
	BSD, SYSV R4 dialects, and Tru64 UNIX (Digital UNIX, DEC
	OSF/1).  It's also available for Linux, and Pyramid DC/OSx
	and Reliant UNIX.

	Even on some SYSV R4 dialects I encountered many problems
	while trying to incorporate /proc file system support.
	The chief problem is that some vendors don't distribute
	the header file that describes the /proc file system node
	-- usually called prdata.h.

17.2	How do I disable the device cache file feature or alter
	it's behavior?

	To disable the device cache file feature for a dialect,
	remove the HASDCACHE definition from the machine.h file of
	the dialect's machine.h header file.  You can also use
	HASDCACHE to change the default prefix (``.lsof'') of the
	device cache file.

	Be sure you consider disabling the device cache file feature
	carefully.  Having a device cache file significantly reduces
	lsof startup overhead by eliminating a full scan of /dev
	(or /devices) once the device cache file has been created.
	That full scan also overloads the kernel's name cache with
	the names of the /dev (or /devices) nodes, reducing the
	opportunity for lsof to find path name components of open
	files.

	If you're worried about the presence of mode 0600 device
	cache files in the home directories of the real user IDs
	that execute lsof, consider these checks that lsof makes
	on the file before using it:

	    1.  To read the device cache file, lsof must gain
		permission from access(2).

	    2.  The device cache file's modes must be 0600 (0644
		if lsof is reading a system-wide device cache file)
		and its size non-zero.

	    3.  There must be a correctly formatted section count
		line at the beginning of the file.

	    4.  Each section must have a header line with a count
	        that properly numbers the lines in the section.
		Legal sections are device, clone, pseudo-device,
		and CRC.

	    5.  The lines of a section must have the proper format.

	    6.  All lines are included in a 16 bit CRC, and it is
		recorded in a non-checksummed section line at the
		end of the file.

	    7.  The checksum computed when the file is read must
		match the checksum recorded when the file was
		written.

	    8.  The checksum section line must be followed by
		end-of-information.

	    9.  Lsof must be able to get matching results from
		stat(2) on a randomly chosen entry of the device
		section.

	For more information on the device cache file, read the
	00DCACHE file of the lsof distribution.

17.2.1	What's the risk with a perverted device cache file?

	Even with the checks that lsof makes on the device cache
	file, it's conceivable that an intruder could modify it so
	it would pass lsof's tests.

	The only serious consequence I know of this change is the
	removal of a file whose major device number identifies a
	socket from some user ID's device cache file.  When such
	a device has been removed from the device cache file, and
	when lsof doesn't detect the removal, lsof may not be able
	to identify socket files when executed by the affected user
	ID.  Only certain dialects are at risk to this attack --
	e.g., SCO OpenServer and Solaris 2.x, 7, 8 BETA, and 8
	BETA-Refresh (but not SunOS 4.1.x).

	If you're tracking a network intruder with lsof, that could
	be important to you.  If you suspect that someone has
	corrupted the device cache file you're using, I recommend
	you use lsof's -Di option to tell it to ignore it and use
	the contents of /dev (or /devices) instead; or remove the
	device cache file (usually .lsof_hostname, where hostname
	is the first component of the host's name returned by
	gethostname(2)) from the user ID's home directory and let
	lsof create a new one for you.

17.2.2	How do I put the full host name in a personal device cache file
	path?

	Lsof constructs the personal device cache file path name
	from a format specified in the HASPERSDC #define in the
	dialect's machine.h header file.  As distributed HASPERSDC
	declares the path to be ``.lsof_'' plus the first component
	of the host name with the format ``.lsof_%L''.

	If you want to change the way lsof constructs the personal
	device cache file path name, you can change the HASPERSDC
	#define and recompile lsof.  If, for example, you #define
	HASPERSDC to be ``.lsof_%l'' (note the lower case `l'),
	Configure and remake lsof, then the personal device cache
	file path will be ``.lsof_'' plus the host name returned
	by gethostname(2).

	See the 00DCACHE file of the lsof distribution for more
	information on the formation of the personal device cache
	file path and the use of the HASPERSDC #define.

17.2.3	How do I put the personal device cache file in /tmp?

	Change the HASPERSDC definition in your dialect's machine.h
	header file.
	
	When you redefine HASPERSDC, make sure you put at least
	one user identification conversion in it to keep separate
	the device cache files for each user of lsof.  Also give
	some thought to including the ``%0'' conversion to define
	an alternate path for setuid-root and root processes.

	Here's a definition that puts a personal device cache file
	in /tmp with the name ``.lsof_UID''.

	    #define HASPERSDC "/tmp/.lsof_%U"

	Thus the personal device cache file path for UID 548 would
	be:

	    /tmp/.lsof_548

	You can add the login name to the path with the ``%u''
	conversion; the full host name with ``%l''; and the first
	host name component with ``%L''.

	CAUTION: be careful using absolute paths like /tmp lest
	lsof processes that are setuid-root or whose real UID is
	root be used to exploit some security weakness via /tmp.
	Elect instead to add an alternate path for those processes
	with the ``%0'' conversion.  Here's an extension of the
	previous HASPERSDC format for /tmp that declares an alternate
	path:

	    #define HASPERSDC "/tmp/.lsof_%U%0%h/.lsof_%l"

	When the lsof process is setuid-root or its real UID is
	root, presuming root's home directory is `/' and the host's
	name is ``vic.cc.purdue.edu'', the extended format yields:

	    /.lsof_vic.cc.purdue.edu

17.3	Why doesn't lsof know about AFS files on my favorite dialect?

	Lsof currently supports AFS for these dialects:

	    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.[56] (AFS 3.4a)
	    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 I have no way to test that.  Lsof may report
	correct information for AFS files on other dialects, but
	I can't test that either.

	AFS support must be custom crafted for each UNIX dialect
	and then tested.  If lsof supports your favorite dialect,
	but doesn't recognize its AFS files, probably I don't have
	access to a test system.  If you want AFS support badly
	for your dialect, consider helping me do the development
	and testing.

17.3.1	Why doesn't lsof report node numbers for all AFS volume files,
	or how do I reveal dynamic module addresses to lsof?

	When AFS is implemented via dynamic kernel modules -- e.g.,
	in NEXTSTEP or SunOS -- lsof can't obtain the addresses of
	AFS variables in the kernel that it uses to identify AFS
	vnodes.  It can guess that a vnode is assigned to an AFS
	file and it can obtain other information about AFS files,
	but it has trouble computing AFS volume node numbers.

	To determine node numbers for AFS volumes other than the
	root volume, /afs, lsof needs access to a hashed volume
	structure pointer table.  When it can't find the address
	of that table, because AFS support is implemented via
	dynamic kernel modules, lsof will return blanks in the
	INODE column for AFS volume files.  Lsof can identify the
	root volume's node number (0), and can compute the node
	numbers for all other AFS files.

	If you have a name list file that contains the addresses
	of the AFS dynamic modules -- e.g., you saved SunOS module
	symbols when you created a loadable module kernel with
	modload(8) by specifying -sym -- lsof may be able to find
	the kernel addresses it needs in that file.

	Lsof looks up AFS dynamic kernel addresses for two dialects
	at these default paths:

	    NEXTSTEP 3.2	/usr/vice/etc/afs_loadable
	    SunOS 4.1.4		/usr/vice/etc/modload/libafs

	A different path to a name list file with AFS dynamic kernel
	addresses may be specified with the -A option, when the -A
	option description appears in lsof's -h or -? (help) output.

	If any addresses appear in the -A name list file that also
	appear in the regular kernel name list file -- e.g., /vmunix
	-- they must match, or lsof will silently ignore the -A
	addresses on the presumption that they are out of date.
