list IDs of all processes that have one or more files open
signal] file ...
fuser utility writes to stdout the PIDs of processes
that have one or more named files open. For block and character special
devices, all processes using files on that device are listed. A file is
considered open by a process if it was explicitly opened, is the working
directory, root directory, jail root directory, active executable text, kernel
trace file or the controlling terminal of the process. If
-m option is specified, the
fuser utility will also look through mmapped files.
The following options are available:
- Treat files as mount points and report on any files open in the file
- The report must be only for named files.
- Send signal to reported processes (
- Extract values associated with the name list from the specified core
instead of the default /dev/kmem.
- Search through mmapped files too.
- Extract the name list from the specified system instead of the default,
which is the kernel image the system has booted from.
- Use given signal name instead of default
- Write the user name associated with each process to stderr.
The following symbols, written to stderr will indicate how files
- The file is open as append only (
- The file is the current workdir directory of the process.
- The process bypasses fs cache while writing to this file
- Exclusive lock is hold.
- The file is the jail root of the process.
- The file is mmapped.
- The file is the root directory of the process.
- Shared lock is hold.
- The file is the kernel tracing file for the process.
- The file is open for writing.
- The file is executable text of the process.
- The process uses this file as its controlling tty.
fuser utility exits 0 on success,
and >0 if an error occurs.
The command ‘
fuser -fu .’ writes to
standard output the process IDs of processes that are using the current
directory and writes to stderr an indication of how those processes are using
the directory and user names associated with the processes that are using this
fuser utility is expected to conform to
IEEE Std 1003.1-2004 (“POSIX.1”).
fuser utility appeared in FreeBSD
fuser utility and this manual page was written by
fuser takes a snapshot of the system, it is only
correct for a very short period of time. When working via
interface the report will be limited to filesystems the
fuser utility knows about (currently only cd9660,
devfs, nfs, ntfs, nwfs, udf, ufs and zfs).