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

.\" Copyright (C) 2003 Andries Brouwer (aeb@cwi.nl)
.\"
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.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
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.\" The pathconf note is from Walter Harms
.\" This is not a system call on Linux
.\"
.\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
.\"
.TH STATVFS 2 2003-08-22 "Linux 2.6.0" "Linux Programmer's Manual"
.SH NAME
statvfs, fstatvfs \- get file system statistics
.SH SYNOPSIS
.B #include <sys/statvfs.h>
.sp
.BI "int statvfs(const char *" path ", struct statvfs *" buf );
.br
.BI "int fstatvfs(int " fd ", struct statvfs *" buf );
.SH DESCRIPTION
The function
.BR statvfs ()
returns information about a mounted file system.
.I path
is the pathname of any file within the mounted filesystem.
.I buf
is a pointer to a
.I statvfs
structure defined approximately as follows:

.nf
struct statvfs {
    unsigned long  f_bsize;    /* file system block size */
    unsigned long  f_frsize;   /* fragment size */
    fsblkcnt_t     f_blocks;   /* size of fs in f_frsize units */
    fsblkcnt_t     f_bfree;    /* # free blocks */
    fsblkcnt_t     f_bavail;   /* # free blocks for non-root */
    fsfilcnt_t     f_files;    /* # inodes */
    fsfilcnt_t     f_ffree;    /* # free inodes */
    fsfilcnt_t     f_favail;   /* # free inodes for non-root */
    unsigned long  f_fsid;     /* file system ID */
    unsigned long  f_flag;     /* mount flags */
    unsigned long  f_namemax;  /* maximum filename length */
};
.fi

Here the types
.B fsblkcnt_t
and
.B fsfilcnt_t
are defined in
.IR <sys/types.h> .
Both used to be
.IR "unsigned long" .

The field
.I f_flag
is a bit mask (of mount flags, see
.BR mount (8)).
Bits defined by POSIX are
.TP
.B ST_RDONLY
Read-only file system.
.TP
.B ST_NOSUID
Set-user-ID/set-group-ID bits are ignored by
.BR exec (2).
.LP
It is unspecified whether all members of the returned struct
have meaningful values on all filesystems.

.BR fstatvfs ()
returns the same information about an open file referenced by descriptor
.IR fd .
.SH "RETURN VALUE"
On success, zero is returned.
On error, \-1 is returned, and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EACCES
.RB ( statvfs ())
Search permission is denied for a component of the path prefix of
.IR path .
(See also
.BR path_resolution (2).)
.TP
.B EBADF
.RB ( fstatvfs ())
.I fd
is not a valid open file descriptor.
.TP
.B EFAULT
.I Buf
or
.I path
points to an invalid address.
.TP
.B EINTR
This call was interrupted by a signal.
.TP
.B EIO
An I/O error occurred while reading from the file system.
.TP
.B ELOOP
.RB ( statvfs ())
Too many symbolic links were encountered in translating
.IR path .
.TP
.B ENAMETOOLONG
.RB ( statvfs ())
.I path
is too long.
.TP
.B ENOENT
.RB ( statvfs ())
The file referred to by
.I path
does not exist.
.TP
.B ENOMEM
Insufficient kernel memory was available.
.TP
.B ENOSYS
The file system does not support this call.
.TP
.B ENOTDIR
.RB ( statvfs ())
A component of the path prefix of
.I path
is not a directory.
.TP
.B EOVERFLOW
Some values were too large to be represented in the returned struct.
.SH "CONFORMING TO"
POSIX.1-2001
.SH NOTES
The Linux kernel has system calls
.BR statfs ()
and
.BR fstatfs ()
to support this library call.

The current glibc implementations of
.sp
.nf
   pathconf(path, _PC_REC_XFER_ALIGN);
   pathconf(path, _PC_ALLOC_SIZE_MIN);
   pathconf(path, _PC_REC_MIN_XFER_SIZE);
.fi
.sp
respectively use the
.IR f_frsize ,
.IR f_frsize ,
and
.IR f_bsize
fields of the return value of
.IR "statvfs(path,buf)" .
.SH "SEE ALSO"
.BR statfs (2)