Ubuntu Manpage: fuser - list process IDs of all processes that have one or more files open

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.

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 .