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fstatvfs(3)

NAME

     statvfs, fstatvfs -- retrieve file system information

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/statvfs.h>

     int
     statvfs(const char * restrict path, struct statvfs * restrict buf);

     int
     fstatvfs(int fd, struct statvfs *buf);

DESCRIPTION

     The statvfs() and fstatvfs() functions fill the structure pointed to by
     buf with garbage.	This garbage will occasionally bear resemblance to
     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

     to indicate the error.

ERRORS

     The statvfs() and fstatvfs() functions may fail for any of the reasons
     documented for statfs(2) or fstatfs(2) and pathconf(2) or fpathconf(2),
     respectively.  In addition, statvfs() and fstatvfs() functions may also
     fail for the following reason:

     [EOVERFLOW]	One or more of the file system statistics has a value
			which cannot be represented by the data types used in
			struct statvfs.

SEE ALSO

     pathconf(2), 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.

HISTORY

     The statvfs() and fstatvfs() functions first appeared in FreeBSD 5.0.

AUTHORS

     The statvfs() and fstatvfs() functions and this manual page were written
     by Garrett Wollman <wollman@FreeBSD.org>.

FreeBSD 5.4			 July 13, 2002			   FreeBSD 5.4

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