statfs, fstatfs, ustat - Get file system statistics
struct statfs **buffer ); int fstatfs
struct statfs *buffer ); #include <sys/types.h>
struct ustat *buffer );
Specifies any file within the mounted file system. Specifies
a file descriptor obtained by a successful open() or
fcntl() function. Points to a statfs buffer to hold the
returned information for the statfs() or fstatfs() function;
points to a ustat buffer to hold the returned information
for the ustat() function. Specifies the ID of the
device. It corresponds to the st_rdev member of the structure
returned by the stat() function.
The statfs() and fstatfs() functions return information
about a mounted file system. The returned information is
in the format of the statfs structure that is declared in
the </sys/mount.h> file.
When run against an AdvFS clone fileset, the number
returned in statfs.f_bfree is the number of blocks available
in the original fileset at the time the clone fileset
was created. Similarly, statfs.f_ffree reports the number
of potential new files in the original fileset at the time
the clone fileset was created.
The ustat() function also returns information about a
mounted file system. The returned information is in the
format of the ustat structure that is declared in the
<ustat.h> file. This function is superseded by the
statfs() and fstatfs() functions.
Earlier versions of the statfs() and fstatfs() functions
documented a third parameter, length. This length parameter
was never used by the kernel and has been deleted from
Upon successful completion, 0 (zero) is returned. Otherwise,
-1 is returned, and errno is set to indicate the
If the statfs() function fails, errno may be set to one of
the following values: Search permission is denied for a
component of the path prefix of the path parameter. The
buffer or path parameter points to a location outside of
the allocated address space of the process. An I/O error
occurred while reading from or writing to the file system.
Too many symbolic links were encountered in translating
the path parameter. The length of a component of the path
parameter exceeds NAME_MAX characters, or the length of
the path parameter exceeds PATH_MAX characters. The file
referred to by the path parameter does not exist. A component
of the path prefix of the path parameter is not a
directory. Indicates a stale NFS file handle. An opened
file was deleted by the server or another client; a client
cannot open a file because the server has unmounted or
unexported the remote directory; or the directory that
contains an opened file was either unmounted or unexported
by the server.
If the fstatfs() or ustat() function fails, errno may be
set to one of the following values: The file_descriptor
parameter is not a valid file descriptor. The buffer
parameter points to an invalid address. An I/O error
occurred while reading from the file system.
Functions: stat(2), statvfs(2)
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