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FUSER(1)				  User Commands 				 FUSER(1)

NAME
       fuser - identify processes using files or sockets

SYNOPSIS
       fuser [-fuv] [-a|-s] [-4|-6] [-c|-m|-n  space ] [-k [-i] [-M] [-w] [-SIGNAL ] ] name ...
       fuser -l
       fuser -V

DESCRIPTION
       fuser  displays	the  PIDs of processes using the specified files or file systems.  In the
       default display mode, each file name is followed by a letter denoting the type of access:

	      c      current directory.

	      e      executable being run.

	      f      open file. f is omitted in default display mode.

	      F      open file for writing. F is omitted in default display mode.

	      r      root directory.

	      m      mmap'ed file or shared library.

       fuser returns a non-zero return code if none of the specified files is accessed or in case
       of a fatal error. If at least one access has been found, fuser returns zero.

       In  order to look up processes using TCP and UDP sockets, the corresponding name space has
       to be selected with the -n option. By default fuser will look in both IPv6 and IPv4  sock-
       ets.  To  change  the  default,	behavior, use the -4 and -6 options. The socket(s) can be
       specified by the local and remote port, and the remote address. All fields  are	optional,
       but commas in front of missing fields must be present:

       [lcl_port][,[rmt_host][,[rmt_port]]]

       Either symbolic or numeric values can be used for IP addresses and port numbers.

       fuser outputs only the PIDs to stdout, everything else is sent to stderr.

OPTIONS
       -a, --all
	      Show  all  files	specified  on  the  command line. By default, only files that are
	      accessed by at least one process are shown.

       -c     Same as -m option, used for POSIX compatibility.

       -f     Silently ignored, used for POSIX compatibility.

       -k, --kill
	      Kill processes accessing the file. Unless changed with -SIGNAL, SIGKILL is sent. An
	      fuser process never kills itself, but may kill other fuser processes. The effective
	      user ID of the process executing fuser is set to its real user ID before attempting
	      to kill.

       -i, --interactive
	      Ask  the	user  for  confirmation before killing a process. This option is silently
	      ignored if -k is not present too.

       -l, --list-signals
	      List all known signal names.

       -m NAME, --mount NAME
	      NAME specifies a file on a mounted file system or a block device that  is  mounted.
	      All  processes accessing files on that file system are listed.  If a directory file
	      is specified, it is automatically changed to NAME/. to use  any  file  system  that
	      might be mounted on that directory.

       -M --ismountpoint
	      Request  will be fulfilled only if NAME specifies a mountpoint.  This is an invalu-
	      able seatbelt which prevents you from killing the machine if NAME happens to not be
	      a filesystem.

       -w     Kill  only processes which have write access. This option is silently ignored if -k
	      is not present too.

       -n SPACE, --namespace SPACE
	      Select a different name space. The name spaces file (file names, the default),  udp
	      (local  UDP  ports), and tcp (local TCP ports) are supported. For ports, either the
	      port number or the symbolic name can be specified. If there is  no  ambiguity,  the
	      shortcut notation name/Ispace (e.g. 80/tcp ) can be used.

       -s, --silent
	      Silent operation. -u and -v are ignored in this mode.  -a must not be used with -s.

       -SIGNAL
	      Use  the specified signal instead of SIGKILL when killing processes. Signals can be
	      specified either by name (e.g. -HUP)  or	by  number  (e.g.  -1).  This  option  is
	      silently ignored if the -k option is not used.

       -u, --user
	      Append the user name of the process owner to each PID.

       -v, --verbose
	      Verbose mode. Processes are shown in a ps-like style. The fields PID, USER and COM-
	      MAND are similar to ps. ACCESS shows how the process  accesses  the  file.  Verbose
	      mode  will  also show when a particular file is being access as a mount point, knfs
	      export or swap file. In this case kernel is shown instead of the PID.

       -V, --version
	      Display version information.

       -4, --ipv4
	      Search only for IPv4 sockets. This option must not be used with the -6  option  and
	      only has an effect with the tcp and udp namespaces.

       -6, --ipv6
	      Search  only  for IPv6 sockets. This option must not be used with the -4 option and
	      only has an effect with the tcp and udp namespaces.

       -      Reset all options and set the signal back to SIGKILL.

FILES
       /proc	 location of the proc file system

EXAMPLES
       fuser -km /home kills all processes accessing the file system /home in any way.

       if fuser -s /dev/ttyS1; then :; else something; fi invokes something if no  other  process
       is using /dev/ttyS1.

       fuser telnet/tcp shows all processes at the (local) TELNET port.

RESTRICTIONS
       Processes  accessing  the  same file or file system several times in the same way are only
       shown once.

       If the same object is specified several times on the command line, some of  those  entries
       may be ignored.

       fuser may only be able to gather partial information unless run with privileges. As a con-
       sequence, files opened by processes belonging to other users may not be	listed	and  exe-
       cutables may be classified as mapped only.

       Installing  fuser  SUID	root will avoid problems associated with partial information, but
       may be undesirable for security and privacy reasons.

       udp and tcp name spaces, and UNIX domain sockets can't be searched with kernels older than
       1.3.78.

       Accesses by the kernel are only shown with the -v option.

       The  -k	option	only  works  on processes. If the user is the kernel, fuser will print an
       advice, but take no action beyond that.

BUGS
       fuser -m /dev/sgX will show (or kill with the -k flag) all processes, even  if  you  don't
       have that device configured. There may be other devices it does this for too.

       fuser  cannot  report on any processes that it doesn't have permission to look at the file
       descriptor table for.  The most common time this problem occurs is when looking for TCP or
       UDP  sockets  when  running  fuser  as  a non-root user. In this case fuser will report no
       access

       The mount -m option will match any file within the save device as the specified file,  use
       the -M option as well if you mean to specify only the mount point.

AUTHORS
       Werner Almesberger <werner@almesberger.net>

       Craig Small <csmall@enc.com.au>

SEE ALSO
       kill(1), killall(1), lsof(8), pkill(1), ps(1), kill(2).

Linux					    2011-06-19					 FUSER(1)
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