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
              Variables 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
       format:


              "%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
          directory. Implementations may write other alphabetic characters to
          indicate 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
          parentheses, 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
       indicating 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)