NAME

statvfs, fstatvfs - get file system information

SYNOPSIS

#include <sys/types.h>
#include <sys/statvfs.h>

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

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

DESCRIPTION

statvfs returns a ``generic superblock'' describing a file system; it can be used to acquire information about mounted file systems. buf is a pointer to a structure (described below) that is filled by the system call.

path should name a file that resides on that file system. The file system type is known to the operating system. Read, write, or execute permission for the named file is not required, but all directories listed in the path name leading to the file must be searchable.

The statvfs structure pointed to by buf includes the following members:

     ulong   f_bsize;         /* preferred file system block size */
     ulong   f_frsize;        /* fundamental filesystem block size
                              (if supported) */
     ulong   f_blocks;        /* total # of blocks on file system
                              in units of f_frsize */
     ulong   f_bfree;         /* total # of free blocks */
     ulong   f_bavail;        /* # of free blocks avail to
                                   non-superuser */
     ulong   f_files;         /* total # of file nodes (inodes) */
     ulong   f_ffree;         /* total # of free file nodes */
     ulong   f_favail;        /* # of inodes avail to
                                   non-superuser*/
     fsid_t  f_fsid;          /* file system id (dev for now) */
     char    f_basetype[FSTYPSZ]; /*  target fs type name,
                                   null-terminated */
     ulong   f_flag;          /* bit mask of flags */
     ulong   f_namemax;       /* maximum file name length */
     char    f_fstr[32];      /* file system specific string */
     ulong   f_filler[16];    /* reserved for future expansion */
f_basetype contains a null-terminated  FSType  name  of  the
mounted target (e.g. s5 mounted over rfs will contain s5).

The following flags can be returned in the f_flag field:
     ST_RDONLY     0x01       /* read-only file system */
     ST_NOSUID     0x02       /* does not support setuid/setgid
                                   semantics */

     ST_NOTRUNC    0x04       /* does not truncate file names
                                   longer than {NAME_MAX}*/

fstatvfs is similar to statvfs, except that the file named by path in statvfs is instead identified by an open file descriptor fildes obtained from a successful open, creat, dup, fcntl, or pipe system call.

statvfs fails if one or more of the following are true:

EACCES Search permission is denied on a component of the path prefix.

EFAULT path or buf points outside the process's allocated address space.

EINTR A signal was caught during statvfs execution.

EIO An I/O error occurred while reading the file system.

ELOOP Too many symbolic links were encountered in translating path.

EMULTIHOP Components of path require hopping to multiple remote machines and file system type does not allow it.

ENAMETOOLONG The length of a path component exceeds {NAME_MAX} characters, or the length of path exceeds {PATH_MAX} characters.

ENOENT Either a component of the path prefix or the file referred to by path does not exist.

ENOLINK path points to a remote machine and the link to that machine is no longer active.

ENOTDIR A component of the path prefix of path is not a directory.

fstatvfs fails if one or more of the following are true:

EFAULT buf points to an invalid address.

EBADF fildes is not an open file descriptor.

EINTR A signal was caught during fstatvfs execution.

EIO An I/O error occurred while reading the file system.

DIAGNOSTICS

Upon successful completion a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.

SEE ALSO

chmod(2), chown(2), creat(2),  link(2),  mknod(2),  pipe(2),
read(2), time(2), unlink(2), utime(2), write(2).