fuser(1p) — Linux manual page

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.1‐2017, 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.1‐2017, 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.1‐2017, 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 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 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:https://www.opengroup.org/unix/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               2017                         FUSER(1P)