lsof is a command meaning "list open files", which is used in many Unix-like systems to report a list of all open files and the processes that opened them. This open source utility was developed and supported by Victor A. Abell, the retired Associate Director of the Purdue University Computing Center. It works in and supports several Unix flavors.[4]
In 1985, Cliff Spencer publishes the ofiles command. Its man page says: "ofiles – who has a file open [...] displays the owner and id of any process accessing a specified device". Spencer compiled it for 4.2BSD and ULTRIX.[6] Moreover, in the newsgroup net.unix-wizards, he further remarks:[7]
With all the chatter about dismounting active file systems, I have posted my program to indicate who is using a particular filesystem, "ofiles" to net.sources.
In 1988, the command fstat ("file status") appears as part of the 4.3BSD-Tahoe release. Its man page says:[8]
fstat identifies open files. A file is considered open if a process has it open, if it is the working directory for a process, or if it is an active pure text file. If no options are specified, fstat reports on all open files.
In 1989, in comp.sources.unix, Vic Abell publishes ports of the ofiles and fstat commands from 4.3BSD-Tahoe to "DYNIX 3.0.1[24] for Sequent Symmetry and Balance, SunOS 4.0 and ULTRIX 2.2".[9][10] Various people had evolved and ported ofiles over the years. Abell contrasted the commands as follows:[10]
Fstat is similar to the ofiles program which I recently submitted. Like ofiles, fstat identifies open files. It's orientation differs slightly from that of ofiles: ofiles starts with a file name and paws through the proc and user structures to identify the file; fstat reads all the proc and user structures, displaying information in all files, optionally applying a few filters to the output (including a single file name filter.)
In combination with netstat -aA and grep, fstat will identify the process associated with a network connection, just as will ofiles.
In 1991, Vic Abell publishes lsof version 1.0 to comp.sources.unix. He notes:[1]
Lsof (for LiSt Open Files) lists files opened by processes on selected Unix systems. It is my answer to those who regularly ask me when I am going to make fstat (comp.sources.unix volume 18, number 107) or ofiles (volume 18, number 57) available on SunOS 4.1.1 or the like.
Lsof is a complete redesign of the fstat/ofiles series, based on the SunOS vnode model. Thus, it has been tested on AIX 3.1.[357], HP-UX [78].x, NeXTStep 2.[01], Sequent Dynix 3.0.12 and 3.1.2, and Sunos 4.1 and 4.1.1. Using available kernel access methods, such as nlist() and kvm_read(), lsof reads process table entries, user areas and file pointers to reach the underlying structures that describe files opened by processes.
In 2018, Vic Abbell publishes lsof version 4.92. The same year, he initiates the transfer of responsibility. He writes:[11]
I will reach 80 years of age later this year and I think it's time for me to end my work on general lsof revision releases.
The lsof code is put on Github and maintenance is transferred.[11][12]
Examplesedit
Open files in the system include disk files, named pipes, network sockets and devices opened by all processes. One use for this command is when a disk cannot be unmounted because (unspecified) files are in use. The listing of open files can be consulted (suitably filtered if necessary) to identify the process that is using the files.
^W. Richard Stevens; Bill Fenner; Andrew M. Rudoff (2003), Unix Network Programming: the Sockets networking API, Addison-Wesley Professional, ISBN978-0-13-141155-5
^RFC: lsfd, a brand new Linux specific replacement for lsof #1418
Sam Nelson's script, an alternative to "lsof -i" for Solaris.
Glsof is two separate utilities (Queries and Filemonitor) based on lsof.
Sloth is a macOS graphical interface for lsof
Manpage of LSOF
May 03, 2024
lsof, command, meaning, list, open, files, which, used, many, unix, like, systems, report, list, open, files, processes, that, opened, them, this, open, source, utility, developed, supported, victor, abell, retired, associate, director, purdue, university, com. lsof is a command meaning list open files which is used in many Unix like systems to report a list of all open files and the processes that opened them This open source utility was developed and supported by Victor A Abell the retired Associate Director of the Purdue University Computing Center It works in and supports several Unix flavors 4 lsofOriginal author s Victor A AbellInitial release1991 33 years ago 1991 1 Stable release4 99 3 2 16 December 2023 4 months ago 16 December 2023 Repositorygithub wbr com wbr lsof org wbr lsofWritten inCOperating systemLinux FreeBSD macOS Solaris NetBSD and OpenBSDPlatformCross platformLicenseBSD license compatible 3 Websitelsof wbr readthedocs wbr io A replacement for Linux lsfd is included in util linux 5 Contents 1 History 2 Examples 3 Lsof output 4 See also 5 References 6 External linksHistory editIn 1985 Cliff Spencer publishes the ofiles command Its man page says ofiles who has a file open displays the owner and id of any process accessing a specified device Spencer compiled it for 4 2BSD and ULTRIX 6 Moreover in the newsgroup net unix wizards he further remarks 7 With all the chatter about dismounting active file systems I have posted my program to indicate who is using a particular filesystem ofiles to net sources In 1988 the command fstat file status appears as part of the 4 3BSD Tahoe release Its man page says 8 fstat identifies open files A file is considered open if a process has it open if it is the working directory for a process or if it is an active pure text file If no options are specified fstat reports on all open files In 1989 in comp sources unix Vic Abell publishes ports of the ofiles and fstat commands from 4 3BSD Tahoe to DYNIX 3 0 1 24 for Sequent Symmetry and Balance SunOS 4 0 and ULTRIX 2 2 9 10 Various people had evolved and ported ofiles over the years Abell contrasted the commands as follows 10 Fstat is similar to the ofiles program which I recently submitted Like ofiles fstat identifies open files It s orientation differs slightly from that of ofiles ofiles starts with a file name and paws through the proc and user structures to identify the file fstat reads all the proc and user structures displaying information in all files optionally applying a few filters to the output including a single file name filter In combination with netstat aA and grep fstat will identify the process associated with a network connection just as will ofiles In 1991 Vic Abell publishes lsof version 1 0 to comp sources unix He notes 1 Lsof for LiSt Open Files lists files opened by processes on selected Unix systems It is my answer to those who regularly ask me when I am going to make fstat comp sources unix volume 18 number 107 or ofiles volume 18 number 57 available on SunOS 4 1 1 or the like Lsof is a complete redesign of the fstat ofiles series based on the SunOS vnode model Thus it has been tested on AIX 3 1 357 HP UX 78 x NeXTStep 2 01 Sequent Dynix 3 0 12 and 3 1 2 and Sunos 4 1 and 4 1 1 Using available kernel access methods such as nlist and kvm read lsof reads process table entries user areas and file pointers to reach the underlying structures that describe files opened by processes In 2018 Vic Abbell publishes lsof version 4 92 The same year he initiates the transfer of responsibility He writes 11 I will reach 80 years of age later this year and I think it s time for me to end my work on general lsof revision releases The lsof code is put on Github and maintenance is transferred 11 12 Examples editOpen files in the system include disk files named pipes network sockets and devices opened by all processes One use for this command is when a disk cannot be unmounted because unspecified files are in use The listing of open files can be consulted suitably filtered if necessary to identify the process that is using the files lsof var COMMAND PID USER FD TYPE DEVICE SIZE OFF NODE NAME syslogd 350 root 5w VREG 222 5 0 440818 var adm messages syslogd 350 root 6w VREG 222 5 339098 6248 var log syslog cron 353 root cwd VDIR 222 5 512 254550 var atjobs To view the port associated with a daemon lsof i n P grep sendmail sendmail 31649 root 4u IPv4 521738 TCP 25 LISTEN From the above one can see that sendmail is listening on its standard port of 25 i Lists IP sockets n Do not resolve hostnames no DNS P Do not resolve port names list port number instead of its name One can also list Unix Sockets by using lsof U Lsof output editThe lsof output describes the identification number of the process PID that has opened the file the process group identification number PGID of the process optional the process identification number of the parent process PPID optional the command the process is executing the owner of the process for all files in use by the process including the executing text file and the shared libraries it is using the file descriptor number of the file if applicable the file s access mode the file s lock status the file s device numbers the file s inode number the file s size or offset the name of the file system containing the file any available components of the file s path name the names of the file s stream components the file s local and remote network addresses the TLI network typically UDP state of the file the TCP state read queue length and write queue length of the file the file s TCP window read and write lengths Solaris only and other file or dialect specific values For a complete list of options see the Lsof 8 Linux manual page 13 See also editfuser Unix stat Unix netstat strace List of Unix commandsReferences edit a b v25i002 lsof a successor to fstat and ofiles comp sources unix Release 4 99 3 16 December 2023 Retrieved 17 December 2023 lsof FAQ 1 9 Is there an lsof license W Richard Stevens Bill Fenner Andrew M Rudoff 2003 Unix Network Programming the Sockets networking API Addison Wesley Professional ISBN 978 0 13 141155 5 RFC lsfd a brand new Linux specific replacement for lsof 1418 Spencer Cliff ofiles 8 groups google com net sources Spencer Cliff ofiles posted to net sources groups google com net unix wizards FSTAT 8 www tuhs org 4 3BSD Tahoe v18i057 REVISED ofiles doesn t need Sun source comp sources unix a b v18i107 Show all open files status comp sources unix a b lsof has moved to GitHub and has a new release Issue 39572 Homebrew homebrew core GitHub lsof maintaining md GitHub lsof org 10 April 2023 lsof Retrieved 16 July 2020 External links editOld site lsof l mailing list mirror of legacy sources lsof 8 Linux Administration and Privileged Commands Manual lsof 8 Darwin and macOS System Manager s Manual Using lsof Lsof FAQ Sam Nelson s PCP script an alternative to lsof i for Solaris Glsof is two separate utilities Queries and Filemonitor based on lsof Sloth is a macOS graphical interface for lsof Manpage of LSOF Retrieved from https en wikipedia org w index php title Lsof amp oldid 1184791438, wikipedia, wiki, book, books, library,
