fuser

 

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 FUSER(1)                  User Commands                  FUSER(1)
 
 
 
NAME
        fuser - identify processes using files or sockets
 
SYNOPSIS
        fuser [-a|-s] [-n space] [-signal] [-kimuv] name ...  [-]
        [-n space] [-signal] [-kimuv] 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.
 
               r      root directory.
 
               m      mmap'ed file or shared library.
 
        fuser returns a non-zero return code if none of the speci­
        fied  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. Then 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.
 
OPTIONS
        -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  pro­
               cesses.  The  effective user ID of the process exe­
               cuting fuser is set to  its  real  user  ID  before
               attempting to kill.
 
        -i     Ask the user for confirmation before killing a pro­
               cess. 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.
 
        -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).
 
        -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 kernel (e.g. in the
               case of a mount point, a swap file,  etc.),  kernel
               is shown instead of the PID.
 
        -V     Display version information.
 
        -      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  com­
        mand 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 secu­
        rity 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 only work for IPv4.
 
        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.
 
AUTHOR
        Werner Almesberger <Werner.Almesberger@epfl.ch>
 
SEE ALSO
        kill(1), killall(1), ps(1), kill(2)
 
 
 
 Linux                    October 25, 1999                FUSER(1)

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