statfs(2) System Calls Manual statfs(2)
NAME
statfs, fstatfs, ustat - Gets file system statistics
SYNOPSIS
#include <sys/mount.h>
int statfs( char *path, struct statfs *buffer)
int fstatfs( int file_descriptor, struct statfs *buffer)
#include <sys/types.h> #include <ustat.h>
int ustat( dev_t device, struct ustat *buffer );
PARAMETERS
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.
DESCRIPTION
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.
[Tru64 UNIX] When run against an AdvFS clone fileset, the number returned in statfs.f_bfree is the number of blocks available in the orig-
inal fileset at the time the clone fileset was created. Similarly, statfs.f_ffree reports the number of potential new files in the origi-
nal 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 This function is superseded by the statfs() and fstatfs() functions.
NOTES
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 the documentation.
RETURN VALUES
Upon successful completion, 0 (zero) is returned. Otherwise, -1 is returned, and errno is set to indicate the error.
ERRORS
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. [Tru64 UNIX] The structure pointed to by the buffer argument cannot correctly represent the value
to be returned.
This error can occur in applications compiled on DIGITAL UNIX systems, on Tru64 UNIX systems earlier than Version 5.0, or on any
system while using the __V40_OBJ_COMPAT compiler macro. These applications use a <statfs> structure not compatible with Tru64 UNIX
Version 5.0 and later systems for the following fields: f_blocks, f_bfree, f_bavail, f_mntonname, f_mntfromname.
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. [Tru64
UNIX] The structure pointed to by the buffer argument cannot correctly represent the value to be returned.
This error can occur in applications compiled on DIGITAL UNIX systems, on Tru64 UNIX systems earlier than Version 5.0, or on any
system while using the __V40_OBJ_COMPAT compiler macro. These applications use a <statfs> structure not compatible with Tru64 UNIX
Version 5.0 and later systems for the following fields: f_blocks, f_bfree, f_bavail, f_mntonname, f_mntfromname.
RELATED INFORMATION
Functions: stat(2) delim off
statfs(2)