#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:


     [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