PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

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

PROLOG         top

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

NAME         top

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

SYNOPSIS         top

       fuser [−cfu] file...

DESCRIPTION         top

       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 privileges to invoke the fuser utility.

OPTIONS         top

       The fuser utility shall conform to the Base Definitions volume of
       POSIX.1‐2008, 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         top

       The following operand shall be supported:

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

STDIN         top

       Not used.

INPUT FILES         top

       The user database.

ENVIRONMENT VARIABLES         top

       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 POSIX.1‐2008, 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         top

       Default.

STDOUT         top

       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         top

       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 real user ID of the process. If
           the user name cannot be resolved from the real user ID of the
           process, the real user ID of the process 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         top

       None.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.

CONSEQUENCES OF ERRORS         top

       Default.

       The following sections are informative.

APPLICATION USAGE         top

       None.

EXAMPLES         top

       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.

           fuser −c <mount point>

       writes to standard output the process IDs of processes that are using
       any file in the file system which is mounted on <mount point> and
       writes to standard error an indication of how those processes are
       using the files.

           fuser <mount point>

       writes to standard output the process IDs of processes that are using
       the file which is named by <mount point> and writes to standard error
       an indication of how those processes are using the file.

           fuser <block device>

       writes to standard output the process IDs of processes that are using
       any file which is on the device named by <block device> and writes to
       standard error an indication of how those processes are using the
       file.

           fuser −f <block device>

       writes to standard output the process IDs of processes that are using
       the file <block device> itself and writes to standard error an
       indication of how those processes are using the file.

RATIONALE         top

       The definition of the fuser utility follows existing practice.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
       Variables, Section 12.2, Utility Syntax Guidelines

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                           FUSER(1P)