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.\"     from: @(#)fstat.1	8.3 (Berkeley) 2/25/94
.\"
.Dd December 15, 2013
.Dt FSTAT 1
.Os
.Sh NAME
.Nm fstat
.Nd display status of open files
.Sh SYNOPSIS
.Nm
.Op Fl Afnv
.Op Fl M Ar core
.Op Fl N Ar system
.Op Fl p Ar pid
.Op Fl u Ar user
.Op Ar
.Sh DESCRIPTION
.Nm
identifies open files.
A file is considered open by a process if it was explicitly opened,
is the working directory, root directory, active pure text, or kernel
trace file for that process.
If no options are specified,
.Nm
reports on all open files in the system.
.Pp
Options:
.Bl -tag -width Ds
.It Fl A
Add an output column with the address of the kernel object (vnode or file),
that can be matched with
.Xr pstat 8
output.
.It Fl f
Restrict examination to files open in the same file systems as
the named file arguments, or to the file system containing the
current directory if there are no additional filename arguments.
For example, to find all files open in the file system where the
directory
.Pa /var/log
resides, type
.Dq Li fstat -f /var/log .
Please see the
.Sx BUGS
section for issues with this option.
.It Fl M
Extract values associated with the name list from the specified core
instead of the default
.Pa /dev/kmem .
.It Fl N
Extract the name list from the specified system instead of the default
.Pa /netbsd .
.It Fl n
Numerical format.
Print the device number (maj,min) of the file system
the file resides in rather than the mount point name; for special
files, print the
device number that the special device refers to rather than the filename
in
.Pa /dev ;
and print the mode of the file in octal instead of symbolic form.
.It Fl p
Report all files open by the specified process.
.It Fl u
Report all files open by the specified user.
.It Fl v
Verbose mode.
Print error messages upon failures to locate particular
system data structures rather than silently ignoring them.
Most of
these data structures are dynamically created or deleted and it is
possible for them to disappear while
.Nm
is running.
This is normal and unavoidable since the rest of the system is running while
.Nm
itself is running.
.It Ar
Restrict reports to the specified files.
.El
.Pp
The following fields are printed:
.Bl -tag -width MOUNT
.It Li USER
The username of the owner of the process (effective UID).
.It Li CMD
The command name of the process.
.It Li PID
The process ID.
.It Li FD
The file number in the per-process open file table or one of the following
special names:
.Pp
.Bl -tag -width MOUNT -offset indent -compact
.It Li text
pure text inode
.It Li wd
current working directory
.It Li root
root inode
.It Li tr
kernel trace file
.El
.Pp
If the file number is followed by an asterisk
.Pq Dq * ,
the file is not an inode, but rather a socket,
.Tn FIFO ,
or there is an error.
In this case the remainder of the line doesn't
correspond to the remaining headers -- the format of the line
is described later under
.Sx SOCKETS .
.It Li MOUNT
If the
.Fl n
flag wasn't specified, this header is present and is the
pathname that the file system the file resides in is mounted on.
.It Li DEV
If the
.Fl n
flag is specified, this header is present and is the
major/minor number of the device that this file resides in.
.It Li INUM
The inode number of the file.
.It Li MODE
The mode of the file.
If the
.Fl n
flag isn't specified, the mode is printed
using a symbolic format (see
.Xr strmode 3 ) ;
otherwise, the mode is printed
as an octal number.
.It Li SZ\&|DV
If the file is not a character or block special file, prints the size of
the file in bytes.
Otherwise, if the
.Fl n
flag is not specified, prints
the name of the special file as located in
.Pa /dev .
If that cannot be
located, or the
.Fl n
flag is specified, prints the major/minor device
number that the special device refers to.
.It Li R/W
This column describes the access mode that the file allows.
The letter
.Dq r
indicates open for reading;
the letter
.Dq w
indicates open for writing.
This field is useful when trying to find the processes that are
preventing a file system from being downgraded to read-only.
.It Li NAME
If filename arguments are specified and the
.Fl f
flag is not, then
this field is present and is the name associated with the given file.
Normally the name cannot be determined since there is no mapping
from an open file back to the directory entry that was used to open
that file.
Also, since different directory entries may reference
the same file (via
.Xr ln 1 ) ,
the name printed may not be the actual
name that the process originally used to open that file.
.El
.Sh SOCKETS
The formatting of open sockets depends on the protocol domain.
In all cases the first field is the domain name and
the second field is the socket type (stream, dgram, etc.).
The remaining fields are protocol dependent.
For TCP, it is the address of the tcpcb, and for UDP, the inpcb (socket pcb).
For
.Ux
domain sockets, its the address of the socket pcb and the name of the
file if available.
Otherwise the address of the connected pcb is printed (if connected).
For other domains, the protocol number and address of the socket itself
are printed.
The attempt is to make enough information available to
permit further analysis without duplicating
.Xr netstat 1 .
.Pp
For example, the addresses mentioned above are the addresses which the
.Dq Li netstat -A
command would print for TCP, UDP, and
.Ux
domain.
For kernels compiled with
.Dv PIPE_SOCKETPAIR
pipes appear as connected
.Ux
domain stream sockets.
A unidirectional
.Ux
domain socket indicates the direction of flow with an arrow
.Po
.Dq \*[Lt]-
or
.Dq -\*[Gt]
.Pc ,
and a full duplex socket shows a double arrow
.Pq Dq \*[Lt]-\*[Gt] .
.Pp
For internet sockets
.Nm
also attempts to print the internet address and port for the
local end of a connection.
If the socket is connected, it also prints the remote internet address
and port.
An asterisk
.Pq Dq *
is used to indicate an INADDR_ANY binding.
.Sh SEE ALSO
.Xr netstat 1 ,
.Xr nfsstat 1 ,
.Xr ps 1 ,
.Xr sockstat 1 ,
.Xr systat 1 ,
.Xr vmstat 1 ,
.Xr fstat 2 ,
.Xr iostat 8 ,
.Xr pstat 8
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.3 tahoe .
.Sh BUGS
Since
.Nm
takes a snapshot of the system, it is only correct for a very short period
of time.
.Pp
Moreover, because DNS resolution and YP lookups cause many file
descriptor changes,
.Nm
does not attempt to translate the internet address and port numbers into
symbolic names.
.Pp
Note that the
.Fl f
option will not list
.Ux
domain sockets open in the file system, because the pathnames in the sockets
may not be absolute and are not deterministic.
To find all the
.Ux
domain sockets, use
.Nm
to list all the sockets, and look for the ones that maybe belong in the
file system.