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 sockets. 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 invaluable 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 COMMAND 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  names-
	      paces.

       -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 names-
	      paces.

       -      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 consequence, files opened by processes  belonging	to
       other users may not be listed and executables 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 rea-
       sons.

       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)