.\" Copyright (C) 1995, Thomas K. Dyas <tdyas@eden.rutgers.edu>

.\"

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.\"

.\" Created  1995-08-09 Thomas K. Dyas <tdyas@eden.rutgers.edu>

.\" Modified 1997-01-31 by Eric S. Raymond <esr@thyrsus.com>

.\" Modified 2001-03-22 by aeb

.\" Modified 2003-08-04 by aeb

.\"

.TH USTAT 2 2017-09-15 "Linux" "Linux Programmer's Manual"

.SH NAME

ustat \- get filesystem statistics

.SH SYNOPSIS

.nf

.B #include <sys/types.h>

.BR "#include <unistd.h>" "    /* libc[45] */"

.BR "#include <ustat.h>" "     /* glibc2 */"

.PP

.BI "int ustat(dev_t " dev ", struct ustat *" ubuf );

.fi

.SH DESCRIPTION

.BR ustat ()

returns information about a mounted filesystem.

.I dev

is a device number identifying a device containing

a mounted filesystem.

.I ubuf

is a pointer to a

.I ustat

structure that contains the following

members:

.PP

.in +4n

.EX

daddr_t f_tfree;      /* Total free blocks */

ino_t   f_tinode;     /* Number of free inodes */

char    f_fname[6];   /* Filsys name */

char    f_fpack[6];   /* Filsys pack name */

.EE

.in

.PP

The last two fields,

.I f_fname

and

.IR f_fpack ,

are not implemented and will

always be filled with null bytes (\(aq\\0\(aq).

.SH RETURN VALUE

On success, zero is returned and the

.I ustat

structure pointed to by

.I ubuf

will be filled in.

On error, \-1 is returned, and

.I errno

is set appropriately.

.SH ERRORS

.TP

.B EFAULT

.I ubuf

points outside of your accessible address space.

.TP

.B EINVAL

.I dev

does not refer to a device containing a mounted filesystem.

.TP

.B ENOSYS

The mounted filesystem referenced by

.I dev

does not support this operation, or any version of Linux before

1.3.16.

.SH CONFORMING TO

SVr4.

.\" SVr4 documents additional error conditions ENOLINK, ECOMM, and EINTR

.\" but has no ENOSYS condition.

.SH NOTES

.BR ustat ()

is deprecated and has been provided only for compatibility.

All new programs should use

.BR statfs (2)

instead.

.SS HP-UX notes

The HP-UX version of the

.I ustat

structure has an additional field,

.IR f_blksize ,

that is unknown elsewhere.

HP-UX warns:

For some filesystems, the number of free inodes does not change.

Such filesystems will return \-1 in the field

.IR f_tinode .

.\" Some software tries to use this in order to test whether the

.\" underlying filesystem is NFS.

For some filesystems, inodes are dynamically allocated.

Such filesystems will return the current number of free inodes.

.SH SEE ALSO

.BR stat (2),

.BR statfs (2)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,

can be found at

\%https://www.kernel.org/doc/man\-pages/.