opendarwin man page for fstatfs

STATFS(2)						      BSD System Calls Manual							 STATFS(2)

NAME
     statfs -- get file system statistics

SYNOPSIS
     #include <sys/param.h>
     #include <sys/mount.h>

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

     int
     fstatfs(int fd, struct statfs *buf);

DESCRIPTION
     Statfs() returns information about a mounted file system.	Path is the path name of any file within the mounted file system.  Buf is a
     pointer to a statfs structure defined as follows:

     typedef struct { int32_t val[2]; } fsid_t;

     #define MFSNAMELEN   15 /* length of fs type name, not inc. nul */
     #define MNAMELEN	  90 /* length of buffer for returned name */

     struct statfs {
	 short	 f_otype;    /* type of file system (reserved: zero) */
	 short	 f_oflags;   /* copy of mount flags (reserved: zero) */
	 long	 f_bsize;    /* fundamental file system block size */
	 long	 f_iosize;   /* optimal transfer block size */
	 long	 f_blocks;   /* total data blocks in file system */
	 long	 f_bfree;    /* free blocks in fs */
	 long	 f_bavail;   /* free blocks avail to non-superuser */
	 long	 f_files;    /* total file nodes in file system */
	 long	 f_ffree;    /* free file nodes in fs */
	 fsid_t  f_fsid;     /* file system id (super-user only) */
	 uid_t	 f_owner;    /* user that mounted the file system */
	 short	 f_reserved1;	     /* reserved for future use */
	 short	 f_type;     /* type of file system (reserved) */
	 long	 f_flags;    /* copy of mount flags (reserved) */
	 long	 f_reserved2[2];     /* reserved for future use */
	 char	 f_fstypename[MFSNAMELEN]; /* fs type name */
	 char	 f_mntonname[MNAMELEN];    /* directory on which mounted */
	 char	 f_mntfromname[MNAMELEN];  /* mounted file system */
	 char	 f_reserved3;	     /* reserved for future use */
	 long	 f_reserved4[4];     /* reserved for future use */
     };

     Fields that are undefined for a particular file system are set to -1.  Fstatfs() returns the same information about an open file referenced
     by descriptor fd.

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

ERRORS
     Statfs() fails if one or more of the following are true:

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

     [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.

     [EACCES]		Search permission is denied for a component of the path prefix of path.

     [ELOOP]		Too many symbolic links were encountered in translating 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.

     Fstatfs() fails if one or more of the following are true:

     [EBADF]		fd 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.

HISTORY
     The statfs() function first appeared in 4.4BSD.

BSD
								 February 11, 1994							       BSD