fuser displays the process IDs of the processes that are using the files specified as arguments.

Each process ID is followed by a letter code. These letter codes are interpreted as follows: if the process is using the file as

c

Indicates that the process is using the file as its current directory.

m

Indicates that the process is using a file mapped with mmap(2). See mmap(2) for details.

n

Indicates that the process is holding a non-blocking mandatory lock on the file.

o

Indicates that the process is using the file as an open file.

r

Indicates that the process is using the file as its root directory.

t

Indicates that the process is using the file as its text file.

y

Indicates that the process is using the file as its controlling terminal.

For block special devices with mounted file systems, all processes using any file on that device are listed. For all types of files (text files, executables, directories, devices, and so forth), only the processes using that file are reported.

If more than one group of files are specified, the options may be respecified for each additional group of files. A lone dash cancels the options currently in force.

The process IDs are printed as a single line on the standard output, separated by spaces and terminated with a single new line. All other output is written on standard error.

Any user can run fuser, but only the superuser can terminate another user's process.

The following options are supported:

-c

Reports on files that are mount points for file systems, and any files within that mounted file system.

-f

Print a report for the named file, not for files within a mounted file system.

-k

Sends the SIGKILL signal to each process. Since this option spawns kills for each process, the kill messages may not show up immediately (see kill(2)).

-n

Lists only processes with non-blocking mandatory locks on a file.

-s sig

Send a signal to each process. The sig option argument specifies one of the symbolic names defined in the <signal.h> header, or a decimal integer signal number. If sig is a symbolic name, it is recognized in a case-independent fashion, without the SIG prefix. The -k option is equivalent to -s KILL or -s 9.

-u

Displays the user login name in parentheses following the process ID.

See environ(5) for descriptions of the following environment variables that affect the execution of fuser: LANG, LC_ALL LC_CTYPE, LC_MESSAGES, and NLSPATH.

See attributes(5) for descriptions of the following attributes:

ps(1), mount(1M), kill(2), mmap(2), signal(3C), attributes(5), environ(5)

Because fuser works with a snapshot of the system image, it may miss processes that begin using a file while fuser is running. Also, processes reported as using a file may have stopped using it while fuser was running. These factors should discourage the use of the -k option.