bsd man page for statfs

STATFS(2)							System Calls Manual							 STATFS(2)

NAME
       statfs, fstatfs - get file system statistics

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

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

       int
       fstatfs(fd,buf)
       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 filesystem.  Buf is a
       pointer to a statfs structure defined as follows:

       #define MNAMELEN 90	 /* length of buffer for returned name */

       struct statfs {
       short   f_type;		 /* type of filesystem (see below) */
       short   f_flags; 	 /* copy of mount flags */
       short   f_bsize; 	 /* fundamental file system block size */
       short   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 */
       ino_t   f_files; 	 /* total file nodes in file system */
       ino_t   f_ffree; 	 /* free file nodes in fs */
       u_long  f_fsid[2];	 /* file system id */
       long    f_spare[4];	 /* spare for later */
       char    f_mntonname[MNAMELEN];	 /* mount point */
       char    f_mntfromname[MNAMELEN];  /* mounted filesystem */
       };
       /*
       * File system types. - Only UFS is supported so the other types are not
       * given.
       */
       #define	 MOUNT_UFS 1	/* Fast Filesystem */

       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.

       [EINVAL] 	   path contains a character with the high-order bit set.

       [ENAMETOOLONG]	   The length of a component of path exceeds 63 characters, or the length of path exceeds 255 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.

4.4 Berkeley Distribution					 December 26, 1995							 STATFS(2)