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

NAME
     statfs, statfs64, fstatfs, fstatfs64 -- 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);

TRANSITIONAL SYNOPSIS (NOW DEPRECATED)
     int
     statfs64(const char *path, struct statfs64 *buf);

     int
     fstatfs64(int fd, struct statfs64 *buf);

DESCRIPTION
     The statfs() routine returns information about a mounted file system.  The path argument is the path
     name of any file or directory within the mounted file system.  The buf argument is a pointer to a
     statfs structure.  When the macro _DARWIN_FEATURE_64_BIT_INODE is not defined (see stat(2) for more
     information on this macro), the statfs structure is defined as:

     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 { /* when _DARWIN_FEATURE_64_BIT_INODE is NOT defined */
         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 */
         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 */
     };

     However, when the macro _DARWIN_FEATURE_64_BIT_INODE is defined, the statfs structure is defined as:

     #define MFSTYPENAMELEN  16 /* length of fs type name including null */
     #define MAXPATHLEN      1024
     #define MNAMELEN        MAXPATHLEN

     struct statfs { /* when _DARWIN_FEATURE_64_BIT_INODE is defined */
         uint32_t    f_bsize;        /* fundamental file system block size */
         int32_t     f_iosize;       /* optimal transfer block size */
         uint64_t    f_blocks;       /* total data blocks in file system */
         uint64_t    f_bfree;        /* free blocks in fs */
         uint64_t    f_bavail;       /* free blocks avail to non-superuser */
         uint64_t    f_files;        /* total file nodes in file system */
         uint64_t    f_ffree;        /* free file nodes in fs */
         fsid_t      f_fsid;         /* file system id */
         uid_t       f_owner;        /* user that mounted the filesystem */
         uint32_t    f_type;         /* type of filesystem */
         uint32_t    f_flags;        /* copy of mount exported flags */
         uint32_t    f_fssubtype;    /* fs sub-type (flavor) */
         char        f_fstypename[MFSTYPENAMELEN];   /* fs type name */
         char        f_mntonname[MAXPATHLEN];        /* directory on which mounted */
         char        f_mntfromname[MAXPATHLEN];      /* mounted filesystem */
         uint32_t    f_reserved[8];  /* For future use */
     };

     Note that the f_fstypename, f_mntonname, and f_mntfromname fields are also wider in this variant.

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

FLAGS
     These are some of the flags that may be present in the f_flags field.

     MNT_RDONLY              A read-only filesystem

     MNT_SYNCHRONOUS         File system is written to synchronously

     MNT_NOEXEC              Can't exec from filesystem

     MNT_NOSUID              Setuid bits are not honored on this filesystem

     MNT_NODEV               Don't interpret special files

     MNT_UNION               Union with underlying filesysten

     MNT_ASYNC               File system written to asynchronously

     MNT_EXPORTED            File system is exported

     MNT_LOCAL               File system is stored locally

     MNT_QUOTA               Quotas are enabled on this file system

     MNT_ROOTFS              This file system is the root of the file system

     MNT_DOVOLFS             File system supports volfs

     MNT_DONTBROWSE          File system is not appropriate path to user data

     MNT_UNKNOWNPERMISSIONS  VFS will ignore ownership information on filesystem objects

     MNT_AUTOMOUNTED         File system was mounted by automounter

     MNT_JOURNALED           File system is journaled

     MNT_DEFWRITE            File system should defer writes

     MNT_MULTILABEL          MAC support for individual labels

     MNT_CPROTECT            File system supports per-file encrypted data protection

CAVEATS
     In Mac OS X versions before 10.4, f_iosize is 4096. On these older systems, use MAXBSIZE instead.

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

ERRORS
     The statfs() routine 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 or directory 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.

     The fstatfs() routine 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.

TRANSITIONAL DESCRIPTION (NOW DEPRECATED)
     The statfs64 and fstatfs64 routines are equivalent to their corresponding non-64-suffixed routine, when
     64-bit inodes are in effect.  They were added before there was support for the symbol variants, and so
     are now deprecated.  Instead of using these, set the _DARWIN_USE_64_BIT_INODE macro before including
     header files to force 64-bit inode support.

     The statfs64 structure used by these deprecated routines is the same as the statfs structure when
     64-bit inodes are in effect (see above).

HISTORY
     The statfs() function first appeared in 4.4BSD. The statfs64() and fstatfs64() first appeared in Max OS
     X 10.5 (Leopard) and are now deprecated in favor of the corresponding symbol variants.

BSD                             August 14, 2008                            BSD