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/space (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)orby 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
          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 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 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.

SEE ALSO

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

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