FUSER(P)                   POSIX Programmer's Manual                  FUSER(P)

NAME
       fuser  -  list process IDs of all processes that have one or more files
       open

SYNOPSIS
       fuser [ -cfu ] file ...

DESCRIPTION
       The fuser utility shall write to standard output  the  process  IDs  of
       processes running on the local system that have one or more named files
       open. For block special devices, all processes using any file  on  that
       device are listed.

       The  fuser utility shall write to standard error additional information
       about the named files indicating how the file is being used.

       Any output for processes running on remote systems that  have  a  named
       file open is unspecified.

       A user may need appropriate privilege to invoke the fuser utility.

OPTIONS
       The  fuser  utility  shall  conform  to  the Base Definitions volume of
       IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.

       The following options shall be supported:

       -c     The file is treated as a  mount  point  and  the  utility  shall
              report on any files open in the file system.

       -f     The report shall be only for the named files.

       -u     The  user  name, in parentheses, associated with each process ID
              written to standard output shall be written to standard error.

OPERANDS
       The following operand shall be supported:

       file   A pathname on which the file or file system is to be reported.

STDIN
       Not used.

INPUT FILES
       The user database.

ENVIRONMENT VARIABLES
       The following environment  variables  shall  affect  the  execution  of
       fuser:

       LANG   Provide  a  default value for the internationalization variables
              that are unset or null. (See  the  Base  Definitions  volume  of
              IEEE Std 1003.1-2001,  Section  8.2,  Internationalization Vari-
              ables for the precedence of internationalization variables  used
              to determine the values of locale categories.)

       LC_ALL If  set  to a non-empty string value, override the values of all
              the other internationalization variables.

       LC_CTYPE
              Determine the locale for  the  interpretation  of  sequences  of
              bytes  of  text  data as characters (for example, single-byte as
              opposed to multi-byte characters in arguments).

       LC_MESSAGES
              Determine the locale that should be used to  affect  the  format
              and contents of diagnostic messages written to standard error.

       NLSPATH
              Determine the location of message catalogs for the processing of
              LC_MESSAGES .

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       The fuser utility shall write the process ID  for  each  process  using
       each  file given as an operand to standard output in the following for-
       mat:

              "%d", <process_id>

STDERR
       The fuser utility shall write diagnostic messages to standard error.

       The fuser utility also shall write the following to standard error:

        * The pathname of each named file is written followed immediately by a
          colon.

        * For  each  process  ID written to standard output, the character 'c'
          shall be written to standard error if the process is using the  file
          as  its  current directory and the character 'r' shall be written to
          standard error if the process is using the file as its  root  direc-
          tory. Implementations may write other alphabetic characters to indi-
          cate other uses of files.

        * When the -u option is specified, characters indicating  the  use  of
          the  file  shall be followed immediately by the user name, in paren-
          theses, corresponding to the process' real user  ID.   If  the  user
          name cannot be resolved from the process' real user ID, the process'
          real user ID shall be written instead of the user name.

       When standard output and standard error are directed to the same  file,
       the  output  shall  be  interleaved so that the filename appears at the
       start of each line, followed by the process ID and characters  indicat-
       ing  the use of the file. Then, if the -u option is specified, the user
       name or user ID for each process using that file shall be written.

       A <newline> shall be written to standard error after  the  last  output
       described above for each file operand.

OUTPUT FILES
       None.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

        0     Successful completion.

       >0     An error occurred.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       None.

EXAMPLES
       The command:

              fuser -fu .

       writes  to  standard output the process IDs of processes that are using
       the current directory and writes to standard error an indication of how
       those  processes  are using the directory and the user names associated
       with the processes that are using the current directory.

RATIONALE
       The definition of the fuser utility follows existing practice.

FUTURE DIRECTIONS
       None.

SEE ALSO
       None.

COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
       event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard
       is  the  referee document. The original Standard can be obtained online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                             FUSER(P)