FUSER(1P)						     POSIX Programmer's Manual							 FUSER(1P)

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

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  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	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 parenthe-
	  ses, 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 Technol-
       ogy -- 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(1P)