statvfs(3) BSD Library Functions Manual statvfs(3)
NAME
fstatvfs, statvfs -- retrieve file system information
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <sys/statvfs.h>
int
fstatvfs(int fildes, struct statvfs *buf);
int
statvfs(const char *restrict path, struct statvfs *restrict buf);
DESCRIPTION
The statvfs() and fstatvfs() functions attempt to fill the structure
pointed to by buf with file system statistics, but portable applications
must not depend on this. Applications must pass a pathname or file
descriptor which refers to a file on the file system in which they are
interested.
The statvfs structure contains the following members:
f_namemax The maximum length in bytes of a file name on this file
system. Applications should use pathconf(2) instead.
f_fsid Not meaningful in this implementation.
f_frsize The size in bytes of the minimum unit of allocation on
this file system. (This corresponds to the f_bsize mem-
ber of struct statfs.)
f_bsize The preferred length of I/O requests for files on this
file system. (Corresponds to the f_iosize member of
struct statfs.)
f_flag Flags describing mount options for this file system; see
below.
In addition, there are three members of type fsfilcnt_t, which represent
counts of file serial numbers (i.e., inodes); these are named f_files,
f_favail, and f_ffree, and represent the number of file serial numbers
which exist in total, are available to unprivileged processes, and are
available to privileged processes, respectively. Likewise, the members
f_blocks, f_bavail, and f_bfree (all of type fsblkcnt_t) represent the
respective allocation-block counts.
There are two flags defined for the f_flag member:
ST_RDONLY The file system is mounted read-only.
ST_NOSUID The semantics of the S_ISUID and S_ISGID file mode bits
are not supported by, or are disabled on, this file sys-
tem.
IMPLEMENTATION NOTES
The statvfs() and fstatvfs() functions are implemented as wrappers around
the statfs() and fstatfs() functions, respectively. Not all the informa-
tion provided by those functions is made available through this inter-
face.
RETURN VALUES
The statvfs() and fstatvfs() functions return the value 0 if successful;
otherwise the value -1 is returned and the global variable errno is set
to indicate the error.
ERRORS
The statvfs() function fails if one or more of the following are true:
[EACCES] Search permission is denied for a component of the
path prefix of path.
[EFAULT] Buf or path points to an invalid address.
[EIO] An I/O error occurred while reading from or writing to
the file system.
[ELOOP] Too many symbolic links were encountered in translat-
ing path.
[ENAMETOOLONG] The length of a component of path exceeds {NAME_MAX}
characters, or the length of path exceeds {PATH_MAX}
characters.
[ENOENT] The file referred to by path does not exist.
[ENOTDIR] A component of the path prefix of Path is not a direc-
tory.
The fstatvfs() functions fails if one or more of the following are true:
[EBADF] fildes is not a valid open file descriptor.
[EFAULT] Buf points to an invalid address.
[EIO] An I/O error occurred while reading from or writing to
the file system.
SEE ALSO
statfs(2)
STANDARDS
The statvfs() and fstatvfs() functions conform to IEEE Std 1003.1-2001
(``POSIX.1''). As standardized, portable applications cannot depend on
these functions returning any valid information at all. This implementa-
tion attempts to provide as much useful information as is provided by the
underlying file system, subject to the limitations of the specified data
types.
AUTHORS
The statvfs() and fstatvfs() manual page was originally written by
Garrett Wollman <wollman@FreeBSD.org>.
BSD July 13, 2002 BSD
Mac OS X 10.8 - Generated Fri Aug 31 05:32:49 CDT 2012