fstat - display status of open files
fstat [-fnov] [-M core] [-N system] [-p pid] [-u user] [file
fstat identifies open files. A file is considered open by a
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, fstat reports on all open files in the system.
The options are as follows:
-f Restrict examination to files open in the same file
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 /usr/src resides, type
# fstat -f /usr/src
Extract values associated with the name list from
core instead of the running kernel.
Extract the name list from the specified system instead of the
-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 /dev. Also,
print the mode
of the file in octal instead of symbolic form.
-o Output file offset. Follow the size field with the
offset. Useful for checking progress as a process
a large file.
-p pid Report all files open by the specified process.
Report all files open by the specified user.
-v Verbose mode. Print error messages upon failures to
system data structures rather than silently
them. Most of these data structures are dynamically
deleted and it is possible for them to disappear
while fstat is
running. This is normal and unavoidable since the
rest of the
system is running while fstat itself is running.
Restrict reports to the specified files.
The following fields are printed:
USER The username of the owner of the process (effective
CMD The command name of the process.
PID The process ID.
FD The file number in the per-process open file table or
one of the
following special names:
text - pure text inode
wd - current working directory
root - root inode
tr - kernel trace file
If the file number is followed by an asterisk (`*'),
the file is
not an inode, but rather a socket, 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
MOUNT If the -n flag wasn't specified, this header is present and is the
pathname that the file system the file resides in is
DEV If the -n flag is specified, this header is present
and is the major/minor
number of the device that this file resides
INUM The inode number of the file.
MODE The mode of the file. If the -n flag isn't specified, the mode is
printed using a symbolic format (see strmode(3));
mode is printed as an octal number.
SZ|DV If the file is not a character or block special file,
size of the file in bytes. Otherwise, if the -n flag
is not specified,
prints the name of the special file as located
in /dev. If
that cannot be located, or the -n flag is specified,
major/minor device number that the special device
R/W This column describes the access mode that the file
letter `r' indicates open for reading; the letter `w'
open for writing. This field is useful when trying
to find the
processes that are preventing a file system from being downgraded
NAME If filename arguments are specified and the -f flag
is not, then
this field is present and is the name associated with
file. Normally the name cannot be determined since
there is no
mapping from an open file back to the directory entry
used to open that file. Also, since different directory entries
may reference the same file (via ln(1)), the name
printed may not
be the actual name that the process originally used
to open that
The formatting of open sockets depends on the protocol domain. In all
cases the first field is the domain name, the second field
is the socket
type (stream, dgram, etc), and the third is the socket flags
hex). The remaining fields are protocol dependent. For
TCP, it is the
address of the tcpcb, and for UDP, the inpcb (socket pcb).
For Unix domain
sockets, it's the address of the socket pcb and the address of the
connected pcb (if connected). Otherwise the protocol number
of the socket itself are printed. The attempt is to make
available to permit further analysis without duplicating netstat(1).
For example, the addresses mentioned above are the addresses
netstat -A command would print for TCP, UDP, and Unix domain. Note that
since pipes are implemented using sockets, a pipe appears as
Unix domain stream socket. A unidirectional Unix domain
the direction of flow with an arrow (``<-'' or ``->''), and
a full duplex
socket shows a double arrow (``<->'').
For AF_INET sockets, fstat also attempts to print the internet address
and port for the local end of a connection. If the socket
it also prints the remote internet address and port. A `*'
is used to
indicate an INADDR_ANY binding. In this case, the use of
(``<--'' or ``-->'') indicates the direction the socket connection was
Every pipe is printed as an address which is the same for
both sides of
the pipe and a state that is built of the letters ``RWE''.
W - The pipe
blocks waiting for the reader to read data. R - The pipe
for the writer to write data. E - The pipe is in EOF state.
Each crypto(4) device is printed with only the kernel address of the device
Each kqueue(2) is printed with some information as to queue
Since these things are normally serviced quickly, it is
likely that nothing
of real importance can be discerned.
Each systrace device is printed with only the kernel address
of the device
netstat(1), nfsstat(1), ps(1), systat(1), iostat(8),
The fstat command appeared in 4.3BSD-Tahoe.
Sockets in use by the kernel, such as those opened by
nfsd(8), will not
be seen by fstat, even though they appear in netstat(1).
Since fstat takes a snapshot of the system, it is only correct for a very
short period of time.
Moreover, because DNS resolution and YP lookups cause many
changes, fstat does not attempt to translate the internet address and
port numbers into symbolic names.
OpenBSD 3.6 February 25, 1994
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