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 .