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[thirdparty/man-pages.git] / man2 / ustat.2

.\" Copyright (C) 1995, Thomas K. Dyas <tdyas@eden.rutgers.edu>
.\"
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.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
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.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
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.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" 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 2003-08-04 "Linux" "Linux Programmer's Manual"
.SH NAME
ustat \- get file system statistics
.SH SYNOPSIS
.nf
.B #include <sys/types.h>
.br
.BR "#include <unistd.h>" "    /* libc[45] */"
.br
.BR "#include <ustat.h>" "     /* glibc2 */"
.sp
.BI "int ustat(dev_t " dev ", struct ustat *" ubuf );
.fi
.SH DESCRIPTION
.BR ustat ()
returns information about a mounted file system.
.I dev
is a device number identifying a device containing
a mounted file system.
.I ubuf
is a pointer to a \fIustat\fP structure that contains the following
members:
.in +4n
.nf

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 */
.fi
.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 file system.
.TP
.B ENOSYS
The mounted file system 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 only been provided 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 file systems, the number of free inodes does not change.
Such file systems will return \-1 in the field
.IR f_tinode .
.\" Some software tries to use this in order to test whether the
.\" underlying file system is NFS.
For some file systems, inodes are dynamically allocated.
Such file systems will return the current number of free inodes.
.SH SEE ALSO
.BR stat (2),
.BR statfs (2)