FUSER linux command manual

FUSER(1)                      User Commands                        FUSER(1)

       fuser - identify processes using files or sockets

       fuser [-a|-s] [-4|-6] [-n space] [-signal] [-kimuv] name ...
       fuser -l
       fuser -V

       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.

              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 corre-
       sponding 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,
       behavour, 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:


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

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

       -k     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  pro-
              cess executing fuser is set to its real user ID before attempt-
              ing to kill.

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

       -l     List all known signal names.

       -m     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.

       -n 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. name/proto) can be used.

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

              Use the specified signal instead of SIGKILL when  killing  pro-
              cesses.  Signals can be specified either by name (e.g. -HUP) or
              by number (e.g. -1).

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

       -v     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. If the access is by the ker-
              nel  (e.g.  in  the  case of a mount point, a swap file, etc.),
              kernel is shown instead of the PID.

       -V     Display version information.

       -4     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

       -6     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

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

       /proc     location of the proc file system

       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.

       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.

       udp and tcp currently  work with IPv6 and IPv4, but the address fields
       can only be IPv4 addresses.

       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.

       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.

       Werner Almesberger 

       Craig Small 

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

Linux                         September 26, 2003                     FUSER(1)