fuser - Lists process IDs of processes that are using one or more files or
/usr/sbin/fuser [-cfu] file...
[Tru64 UNIX] The following format shows extensions not included in the XCU
specification for this utility:
/usr/sbin/fuser [ -cdfku] [ -h] [-vH ] file ...
Interfaces documented on this reference page conform to industry standards
Refer to the standards(5) reference page for more information about indus-
try standards and associated tags.
-c Identifies file as a mount point. In this case, fuser reports on any
files that are open in the mounted file system.
-d Reports any referenced files that have been deleted including the
referencing PID and the block count for the file in 512 byte block
-f Requests a report only for the specified files. If a specified file is
a mount point, fuser reports only on that file, not on any files below
-H [Tru64 UNIX] Suppresses column headings in fuser output when used
with the -v option.
-h [Tru64 UNIX] Directs fuser to display information about its command-
-k [Tru64 UNIX] Directs fuser to send a SIGKILL signal to each process.
Because this option spawns a kill operation for each process, the kill
messages may not show up immediately.
-u Directs fuser to show the user login name, in parentheses, associated
with each process ID.
-v [Tru64 UNIX] Directs fuser to display results in verbose form.
- [Tru64 UNIX] Directs fuser to ignore previous option settings for the
next set of file parameters. The - operand allows you to apply dif-
ferent options to different sets of files in the same command line.
Specifies the pathname of the file or the mount point of the file sys-
tem on which fuser reports.
The fuser utility writes to standard output the process IDs of processes
that are running on the local system and have one or more files or file
structures in use. The utility writes to standard error additional informa-
tion about these resources that indicates how each resource is being used.
If file identifies a block special device, fuser lists all processes using
any file on that device.
This utility does not display information about files for which you do not
have the appropriate privileges. For information on many files, root
privilege may be required. Furthermore, you must have appropriate
privileges to use the -k option.
The utility uses the following format to write the process ID for each pro-
cess using each file:
The fuser utility writes diagnostic messages to standard error.
In addition, the utility writes the following information to standard
+ The pathname of each file, immediately followed by a colon.
+ For each process ID written to standard output, one of the following
c If the process is using the file as its current directory.
m [Tru64 UNIX] If the process is using a memory-mapped file.
p [Tru64 UNIX] If the process is using the file as the parent of
its current directory.
r If the process is using the file as its root directory.
o [Tru64 UNIX] If the process has the file open.
y [Tru64 UNIX] If the process is using the file as its controlling
t [Tru64 UNIX] If the process is using the text file as an execut-
If you specify the -u option, characters indicating the use of the
file are followed immediately by the user name, in parentheses, that
corresponds to the process's real user ID. If the user name cannot be
resolved from the process's real user ID, the process's real user ID
is written instead of the user name.
When standard output and standard error are directed to the same file, the
utility intersperses output so that the file appears at the start of each
line, followed by the process ID and the characters indicating file use.
Then, if the -u option is specified, the utility writes the user name or
user ID for each process that is using that file. The utility writes a new-
line character at the end of output for each file.
[Tru64 UNIX] The fuser utility may not report on processes that begin
using a file while the utility is running. Furthermore, processes that
fuser reports are using a file may have stopped using it while the utility
If an accounting file has been opened by an acct() sytem call, the fuser
command and system call will report any match as being open by the kernel
The fuser utility returns the following exit values:
0 Successful completion.
>>0 An error occurred.
1. The following command lists the process IDs of processes using the
2. The following command writes to standard output the process IDs of
processes that are using the current directory. The command writes to
standard error an indication of how those processes are using the
directory and the user names associated with those processes.
The following environment variables affect this utility:
Provides a default value for the locale variables that are unset or
null. If LANG is unset or null, the corresponding value from the POSIX
(C) locale is used. If any of the locale variables contain an invalid
setting, the utility behaves as if none of the variables had been set.
If set to a non-empty string value, overrides the values of all the
other locale variables.
Specifies the locale used to interpret sequences of bytes of text data
as characters (for example, determines whether arguments contain
single-byte or multibyte characters).
Specifies the locale that affects the format and contents of diagnostic
messages written to standard error.
Determines the location of message catalogs for the processing of
Functions: fuser(2), kill(2)